diff --git a/.codacy.yml b/.codacy.yml
new file mode 100644
index 00000000..283e92f4
--- /dev/null
+++ b/.codacy.yml
@@ -0,0 +1,5 @@
+---
+exclude_paths:
+  - 'opt4j-viewer/src/main/java/ptolemy/**/*'
+  - '**/*.py'
+  - '**/*.js'
\ No newline at end of file
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/dtlz/DTLZModule.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/dtlz/DTLZModule.java
index 87b6dc36..dfc3def3 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/dtlz/DTLZModule.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/dtlz/DTLZModule.java
@@ -304,7 +304,7 @@ public void config() {
 			creator = BinaryCreator.class;
 			decoder = BinaryToDoubleDecoder.class;
 			break;
-		case DOUBLE:
+		default: // DOUBLE
 			creator = DoubleCreator.class;
 			decoder = DoubleCopyDecoder.class;
 			break;
@@ -334,6 +334,7 @@ public void config() {
 			break;
 		default:
 			evaluator = DTLZ1.class;
+			break;
 		}
 
 		bindConstant(N.class).to(n);
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/knapsack/KnapsackModule.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/knapsack/KnapsackModule.java
index d3d4639b..7ec57e11 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/knapsack/KnapsackModule.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/knapsack/KnapsackModule.java
@@ -27,8 +27,9 @@
 import org.opt4j.core.start.Constant;
 
 /**
- * The multiobjective 0/1 ILP knapsack problem as proposed in Zitzler and Thiele 1999. Either one of the nine benchmark
- * problems from Zitzler and Thiele 1999 can be selected or the number of knapsacks and items can be set manually.
+ * The multiobjective 0/1 ILP knapsack problem as proposed in Zitzler and Thiele
+ * 1999. Either one of the nine benchmark problems from Zitzler and Thiele 1999
+ * can be selected or the number of knapsacks and items can be set manually.
  * 
  * @see <a href=
  *      "http://www.tik.ee.ethz.ch/sop/download/supplementary/testProblemSuite/">http://www.tik.ee.ethz.ch/sop/download/supplementary/testProblemSuite/</a>
@@ -130,7 +131,7 @@ protected void config() {
 		}
 
 		switch (representation) {
-		case BITSTRING:
+		default: // BITSTRING
 			bindProblem(KnapsackBinaryCreatorDecoder.class, KnapsackBinaryCreatorDecoder.class,
 					KnapsackProfitEvaluator.class);
 			break;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensErrorEvaluator.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensErrorEvaluator.java
index 8ea832da..cab00ea8 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensErrorEvaluator.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensErrorEvaluator.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.benchmarks.queens;
 
 import static org.opt4j.core.Objective.Sign.MIN;
@@ -82,6 +81,22 @@ public Objectives evaluate(QueensBoard queensBoard) {
 	 */
 	private int countErrors(QueensBoard queensBoard) {
 		int errorcount = 0;
+
+		errorcount += countErrorsRowsColumns(queensBoard);
+		errorcount += countErrorsDiagonals(queensBoard);
+
+		return errorcount;
+	}
+
+	/**
+	 * Helper function to count the errors in rows and columns.
+	 * 
+	 * @param queensBoard
+	 *            the board
+	 * @return the error count in rows and columns
+	 */
+	protected int countErrorsRowsColumns(QueensBoard queensBoard) {
+		int errorcount = 0;
 		int size = problem.size();
 
 		for (int i = 0; i < size; i++) {
@@ -106,6 +121,20 @@ private int countErrors(QueensBoard queensBoard) {
 			errorcount += sum;
 		}
 
+		return errorcount;
+	}
+
+	/**
+	 * Helper function to count the errors in diagonals.
+	 * 
+	 * @param queensBoard
+	 *            the board
+	 * @return the error count in diagonals
+	 */
+	protected int countErrorsDiagonals(QueensBoard queensBoard) {
+		int errorcount = 0;
+		int size = problem.size();
+
 		for (int k = -size + 1; k < size; k++) {
 			// diagonal 1
 			int sum = 0;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensModule.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensModule.java
index 969c8309..66a5a30c 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensModule.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensModule.java
@@ -63,13 +63,6 @@ public class QueensModule extends ProblemModule {
 	@Order(3)
 	protected Dec decoder = Dec.SAT;
 
-	/**
-	 * Constructs a {@link QueensModule}.
-	 */
-	public QueensModule() {
-		super();
-	}
-
 	/**
 	 * The {@link Decoder} strategy for the queens problem.
 	 * 
@@ -105,7 +98,7 @@ public void config() {
 		Class<? extends Decoder<?, ?>> decoderClass = null;
 
 		switch (decoder) {
-		case SAT:
+		default: // SAT
 			creatorClass = QueensSATDecoder.class;
 			decoderClass = QueensSATDecoder.class;
 			break;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensSATDecoder.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensSATDecoder.java
index a0e04ade..571a1884 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensSATDecoder.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/queens/QueensSATDecoder.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.benchmarks.queens;
 
@@ -90,7 +89,20 @@ public QueensBoard convertModel(Model model) {
 	@Override
 	public Set<Constraint> createConstraints() {
 		Set<Constraint> constraints = new HashSet<Constraint>();
+
+		constraints.addAll(createConstraintsRowsColumns());
+		constraints.addAll(createConstraintsDiagonal());
+		return constraints;
+	}
+
+	/**
+	 * Helper function for createConstraints() that creates the constraints regarding rows and columns.
+	 * 
+	 * @return constraints regarding rows and columns
+	 */
+	protected Set<Constraint> createConstraintsRowsColumns() {
 		int size = problem.size();
+		Set<Constraint> constraints = new HashSet<Constraint>();
 
 		for (int i = 0; i < size; i++) {
 
@@ -112,6 +124,19 @@ public Set<Constraint> createConstraints() {
 			constraints.add(constraint);
 		}
 
+		return constraints;
+
+	}
+
+	/**
+	 * Helper function for createConstraints() that creates the constraints regarding diagonals.
+	 * 
+	 * @return constraints regarding diagonals
+	 */
+	protected Set<Constraint> createConstraintsDiagonal() {
+		int size = problem.size();
+		Set<Constraint> constraints = new HashSet<Constraint>();
+
 		for (int k = -size + 1; k < size; k++) {
 			// diagonal 1
 			Constraint constraint = new Constraint("<=", 1);
@@ -137,5 +162,6 @@ public Set<Constraint> createConstraints() {
 		}
 
 		return constraints;
+
 	}
 }
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG1.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG1.java
index 1df65bcb..463c7ff6 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG1.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG1.java
@@ -66,7 +66,7 @@ protected static List<Double> t1(final List<Double> y, final int k) {
 		}
 
 		for (int i = k; i < n; i++) {
-			t.add(WFGTransFunctions.s_linear(y.get(i), 0.35));
+			t.add(WFGTransFunctions.sLinear(y.get(i), 0.35));
 		}
 
 		return t;
@@ -85,7 +85,7 @@ protected static List<Double> t2(final List<Double> y, final int k) {
 		}
 
 		for (int i = k; i < n; i++) {
-			t.add(WFGTransFunctions.b_flat(y.get(i), 0.8, 0.75, 0.85));
+			t.add(WFGTransFunctions.bFlat(y.get(i), 0.8, 0.75, 0.85));
 		}
 
 		return t;
@@ -96,7 +96,7 @@ protected static List<Double> t3(final List<Double> y) {
 		List<Double> t = new ArrayList<Double>();
 
 		for (int i = 0; i < n; i++) {
-			t.add(WFGTransFunctions.b_poly(y.get(i), 0.02));
+			t.add(WFGTransFunctions.bPoly(y.get(i), 0.02));
 		}
 
 		return t;
@@ -125,13 +125,13 @@ protected static List<Double> t4(final List<Double> y, final int k, final int M)
 			final List<Double> y_sub = y.subList(head, tail);
 			final List<Double> w_sub = w.subList(head, tail);
 
-			t.add(WFGTransFunctions.r_sum(y_sub, w_sub));
+			t.add(WFGTransFunctions.rSum(y_sub, w_sub));
 		}
 
 		final List<Double> y_sub = y.subList(k, n);
 		final List<Double> w_sub = w.subList(k, n);
 
-		t.add(WFGTransFunctions.r_sum(y_sub, w_sub));
+		t.add(WFGTransFunctions.rSum(y_sub, w_sub));
 
 		return t;
 	}
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG2.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG2.java
index 78cb7289..9f1b9764 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG2.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG2.java
@@ -70,7 +70,7 @@ protected static List<Double> t2(final List<Double> y, final int k) {
 			final int head = k + 2 * (i - k) - 2;
 			final int tail = k + 2 * (i - k);
 
-			t.add(WFGTransFunctions.r_nonsep(y.subList(head, tail), 2));
+			t.add(WFGTransFunctions.rNonsep(y.subList(head, tail), 2));
 		}
 
 		return t;
@@ -98,13 +98,13 @@ protected static List<Double> t3(final List<Double> y, final int k, final int M)
 			final List<Double> y_sub = y.subList(head, tail);
 			final List<Double> w_sub = w.subList(head, tail);
 
-			t.add(WFGTransFunctions.r_sum(y_sub, w_sub));
+			t.add(WFGTransFunctions.rSum(y_sub, w_sub));
 		}
 
 		final List<Double> y_sub = y.subList(k, n);
 		final List<Double> w_sub = w.subList(k, n);
 
-		t.add(WFGTransFunctions.r_sum(y_sub, w_sub));
+		t.add(WFGTransFunctions.rSum(y_sub, w_sub));
 
 		return t;
 	}
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG4.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG4.java
index 18b26a49..b8626ef2 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG4.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG4.java
@@ -58,7 +58,7 @@ public static List<Double> t1(final List<Double> y) {
 		List<Double> t = new ArrayList<Double>();
 
 		for (int i = 0; i < n; i++) {
-			t.add(WFGTransFunctions.s_multi(y.get(i), 30, 10, 0.35));
+			t.add(WFGTransFunctions.sMulti(y.get(i), 30, 10, 0.35));
 		}
 
 		return t;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG5.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG5.java
index 00b980ca..dff7f264 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG5.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG5.java
@@ -58,7 +58,7 @@ protected static List<Double> t1(final List<Double> y) {
 		List<Double> t = new ArrayList<Double>();
 
 		for (int i = 0; i < n; i++) {
-			t.add(WFGTransFunctions.s_decept(y.get(i), 0.35, 0.001, 0.05));
+			t.add(WFGTransFunctions.sDecept(y.get(i), 0.35, 0.001, 0.05));
 		}
 
 		return t;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG6.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG6.java
index f0149505..d995b2d7 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG6.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG6.java
@@ -68,12 +68,12 @@ public static List<Double> t2(final List<Double> y, final int k, final int M) {
 
 			final List<Double> y_sub = y.subList(head, tail);
 
-			t.add(WFGTransFunctions.r_nonsep(y_sub, k / (M - 1)));
+			t.add(WFGTransFunctions.rNonsep(y_sub, k / (M - 1)));
 		}
 
 		final List<Double> y_sub = y.subList(k, n);
 
-		t.add(WFGTransFunctions.r_nonsep(y_sub, n - k));
+		t.add(WFGTransFunctions.rNonsep(y_sub, n - k));
 
 		return t;
 	}
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG7.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG7.java
index 3f193cf5..f4f79cd5 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG7.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG7.java
@@ -69,9 +69,9 @@ public static List<Double> t1(final List<Double> y, final int k) {
 			final List<Double> y_sub = y.subList(i + 1, n);
 			final List<Double> w_sub = w.subList(i + 1, n);
 
-			final double u = WFGTransFunctions.r_sum(y_sub, w_sub);
+			final double u = WFGTransFunctions.rSum(y_sub, w_sub);
 
-			t.add(WFGTransFunctions.b_param(y.get(i), u, 0.98 / 49.98, 0.02, 50));
+			t.add(WFGTransFunctions.bParam(y.get(i), u, 0.98 / 49.98, 0.02, 50));
 		}
 
 		for (int i = k; i < n; i++) {
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG8.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG8.java
index 438bc178..f15d48ce 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG8.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG8.java
@@ -73,9 +73,9 @@ protected static List<Double> t1(final List<Double> y, final int k) {
 			final List<Double> y_sub = y.subList(0, i);
 			final List<Double> w_sub = w.subList(0, i);
 
-			final double u = WFGTransFunctions.r_sum(y_sub, w_sub);
+			final double u = WFGTransFunctions.rSum(y_sub, w_sub);
 
-			t.add(WFGTransFunctions.b_param(y.get(i), u, 0.98 / 49.98, 0.02, 50));
+			t.add(WFGTransFunctions.bParam(y.get(i), u, 0.98 / 49.98, 0.02, 50));
 		}
 
 		return t;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG9.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG9.java
index 67601c7b..220dcc1c 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG9.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFG9.java
@@ -66,9 +66,9 @@ protected static List<Double> t1(final List<Double> y) {
 			final List<Double> y_sub = y.subList(i + 1, n);
 			final List<Double> w_sub = w.subList(i + 1, n);
 
-			final double u = WFGTransFunctions.r_sum(y_sub, w_sub);
+			final double u = WFGTransFunctions.rSum(y_sub, w_sub);
 
-			t.add(WFGTransFunctions.b_param(y.get(i), u, 0.98 / 49.98, 0.02, 50));
+			t.add(WFGTransFunctions.bParam(y.get(i), u, 0.98 / 49.98, 0.02, 50));
 		}
 
 		t.add(y.get(n - 1));
@@ -85,11 +85,11 @@ protected static List<Double> t2(final List<Double> y, final int k) {
 		List<Double> t = new ArrayList<Double>();
 
 		for (int i = 0; i < k; i++) {
-			t.add(WFGTransFunctions.s_decept(y.get(i), 0.35, 0.001, 0.05));
+			t.add(WFGTransFunctions.sDecept(y.get(i), 0.35, 0.001, 0.05));
 		}
 
 		for (int i = k; i < n; i++) {
-			t.add(WFGTransFunctions.s_multi(y.get(i), 30, 95, 0.35));
+			t.add(WFGTransFunctions.sMulti(y.get(i), 30, 95, 0.35));
 		}
 
 		return t;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGEvaluator.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGEvaluator.java
index 67c9582a..0a5c0e57 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGEvaluator.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGEvaluator.java
@@ -109,7 +109,7 @@ protected static List<Double> calculateF(final List<Double> x, final List<Double
 			S.add(m * 2.0);
 		}
 
-		return caculateF(x, h, S);
+		return calculateF(x, h, S);
 	}
 
 	protected static List<Double> normalizeZ(final List<Double> z, final List<Double> z_max) {
@@ -146,7 +146,7 @@ protected static List<Double> calculateX(final List<Double> t_p, final List<Bool
 		return result;
 	}
 
-	protected static List<Double> caculateF(final List<Double> x, final List<Double> h, final List<Double> S) {
+	protected static List<Double> calculateF(final List<Double> x, final List<Double> h, final List<Double> S) {
 		assert (x.size() == h.size());
 		assert (h.size() == S.size());
 
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI1.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI1.java
index 3c76cd8e..7acf523a 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI1.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI1.java
@@ -80,7 +80,7 @@ protected static List<Double> shape(final List<Double> t_p) {
 			S.add(1.0);
 		}
 
-		return caculateF(x, h, S);
+		return calculateF(x, h, S);
 	}
 
 	/*
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI3.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI3.java
index 115f5849..b34ca313 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI3.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGI3.java
@@ -68,9 +68,9 @@ public static List<Double> t1(final List<Double> y) {
 			final List<Double> y_sub = y.subList(0, i);
 			final List<Double> w_sub = w.subList(0, i);
 
-			final double u = WFGTransFunctions.r_sum(y_sub, w_sub);
+			final double u = WFGTransFunctions.rSum(y_sub, w_sub);
 
-			t.add(WFGTransFunctions.b_param(y.get(i), u, 0.98 / 49.98, 0.02, 50));
+			t.add(WFGTransFunctions.bParam(y.get(i), u, 0.98 / 49.98, 0.02, 50));
 		}
 
 		return t;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGModule.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGModule.java
index 1228c356..b5672108 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGModule.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGModule.java
@@ -304,7 +304,7 @@ public void config() {
 		Class<? extends Evaluator<?>> evaluator = null;
 
 		switch (encoding) {
-		case BINARY:
+		default: //BINARY
 			creator = BinaryCreator.class;
 			decoder = BinaryToDoubleDecoder.class;
 			break;
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGTransFunctions.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGTransFunctions.java
index 47b09962..53a2edb5 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGTransFunctions.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/wfg/WFGTransFunctions.java
@@ -59,7 +59,7 @@ public static double corretToZeroOne(final double a) {
 
 	}
 
-	public static double b_poly(final double y, final double alpha) {
+	public static double bPoly(final double y, final double alpha) {
 		assert (y >= 0.0);
 		assert (y <= 1.0);
 		assert (alpha > 0.0);
@@ -75,7 +75,7 @@ public static double b_poly(final double y, final double alpha) {
 		return result;
 	}
 
-	public static double b_flat(final double y, final double A, final double B, final double C) {
+	public static double bFlat(final double y, final double A, final double B, final double C) {
 		assert (y >= 0.0);
 		assert (y <= 1.0);
 		assert (A >= 0.0);
@@ -103,7 +103,7 @@ public static double b_flat(final double y, final double A, final double B, fina
 		return result;
 	}
 
-	public static double b_param(final double y, final double u, final double A, final double B, final double C) {
+	public static double bParam(final double y, final double u, final double A, final double B, final double C) {
 		assert (y >= 0.0);
 		assert (y <= 1.0);
 		assert (u >= 0.0);
@@ -125,7 +125,7 @@ public static double b_param(final double y, final double u, final double A, fin
 		return result;
 	}
 
-	public static double s_linear(final double y, final double A) {
+	public static double sLinear(final double y, final double A) {
 		assert (y >= 0.0);
 		assert (y <= 1.0);
 		assert (A > 0.0);
@@ -141,7 +141,7 @@ public static double s_linear(final double y, final double A) {
 		return result;
 	}
 
-	public static double s_decept(final double y, final double A, final double B, final double C) {
+	public static double sDecept(final double y, final double A, final double B, final double C) {
 		assert (y >= 0.0);
 		assert (y <= 1.0);
 		assert (A > 0.0);
@@ -166,7 +166,7 @@ public static double s_decept(final double y, final double A, final double B, fi
 		return result;
 	}
 
-	public static double s_multi(final double y, final double A, final double B, final double C) {
+	public static double sMulti(final double y, final double A, final double B, final double C) {
 		assert (y >= 0.0);
 		assert (y <= 1.0);
 		assert (A >= 1);
@@ -188,7 +188,7 @@ public static double s_multi(final double y, final double A, final double B, fin
 		return result;
 	}
 
-	public static double r_sum(final List<Double> y, final List<Double> w) {
+	public static double rSum(final List<Double> y, final List<Double> w) {
 		assert (!y.isEmpty());
 		assert (w.size() == y.size());
 
@@ -212,7 +212,7 @@ public static double r_sum(final List<Double> y, final List<Double> w) {
 		return result;
 	}
 
-	public static double r_nonsep(final List<Double> y, final int A) {
+	public static double rNonsep(final List<Double> y, final int A) {
 		final int y_len = y.size();
 
 		assert (y_len != 0);
diff --git a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/zdt/ZDTModule.java b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/zdt/ZDTModule.java
index de02bc73..1d638697 100644
--- a/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/zdt/ZDTModule.java
+++ b/opt4j-benchmarks/src/main/java/org/opt4j/benchmarks/zdt/ZDTModule.java
@@ -194,6 +194,7 @@ public void setFunction(Function function) {
 			break;
 		default:
 			n = 30;
+			break;
 		}
 
 	}
@@ -254,6 +255,15 @@ public void config() {
 			creator = DoubleCreator.class;
 			decoder = DoubleCopyDecoder.class;
 			break;
+		default:
+			if (function == Function.ZDT5) {
+				creator = ZDT5BinaryCreator.class;
+				decoder = BinaryCopyDecoder.class;
+			} else {
+				creator = BinaryCreator.class;
+				decoder = BinaryToDoubleDecoder.class;
+			}
+			break;
 		}
 
 		switch (function) {
diff --git a/opt4j-core/src/main/java/org/opt4j/core/Genotype.java b/opt4j-core/src/main/java/org/opt4j/core/Genotype.java
index 2d312b6a..6054d7e3 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/Genotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/Genotype.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.core;
 
 /**
diff --git a/opt4j-core/src/main/java/org/opt4j/core/Objective.java b/opt4j-core/src/main/java/org/opt4j/core/Objective.java
index 65895cc5..3591ada4 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/Objective.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/Objective.java
@@ -172,9 +172,7 @@ public boolean equals(Object obj) {
 				return false;
 		} else if (!name.equals(other.name))
 			return false;
-		if (sign != other.sign)
-			return false;
-		return true;
+		return sign == other.sign;
 	}
 
 }
diff --git a/opt4j-core/src/main/java/org/opt4j/core/common/archive/PopulationArchive.java b/opt4j-core/src/main/java/org/opt4j/core/common/archive/PopulationArchive.java
index 97d4eb57..3311516e 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/common/archive/PopulationArchive.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/common/archive/PopulationArchive.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.core.common.archive;
 
@@ -52,7 +51,8 @@ public boolean update(Set<? extends Individual> individuals) {
 
 		List<Individual> candidates = new ArrayList<Individual>(individuals);
 
-		Objectives o1, o2;
+		Objectives o1;
+		Objectives o2;
 		for (int i = 0; i < candidates.size() - 1; i++) {
 			o1 = candidates.get(i).getObjectives();
 			for (int j = i + 1; j < candidates.size(); j++) {
diff --git a/opt4j-core/src/main/java/org/opt4j/core/common/archive/UnboundedArchive.java b/opt4j-core/src/main/java/org/opt4j/core/common/archive/UnboundedArchive.java
index d54e2bf2..52c48a1a 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/common/archive/UnboundedArchive.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/common/archive/UnboundedArchive.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.core.common.archive;
 
 import java.util.Collection;
@@ -38,19 +37,11 @@
 @Singleton
 public class UnboundedArchive extends AbstractArchive {
 
-	/**
-	 * Constructs a new archive of unbounded size.
-	 */
-	public UnboundedArchive() {
-		super();
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * 
-	 * @see
-	 * org.opt4j.common.archive.AbstractArchive#addNondominated(java.util.Collection
-	 * )
+	 * @see org.opt4j.common.archive.AbstractArchive#addNondominated(java.util.
+	 * Collection )
 	 */
 	@Override
 	protected boolean updateWithNondominated(Collection<Individual> candidates) {
diff --git a/opt4j-core/src/main/java/org/opt4j/core/common/random/MTRandom.java b/opt4j-core/src/main/java/org/opt4j/core/common/random/MTRandom.java
index 4898a775..4ead244d 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/common/random/MTRandom.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/common/random/MTRandom.java
@@ -32,8 +32,8 @@
  *         <p>
  *         A Java implementation of the MT19937 (Mersenne Twister) pseudo random
  *         number generator algorithm based upon the original C code by Makoto
- *         Matsumoto and Takuji Nishimura (see <a
- *         href="http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html">
+ *         Matsumoto and Takuji Nishimura (see
+ *         <a href="http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html">
  *         http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html</a> for more
  *         information.
  *         <p>
@@ -50,21 +50,21 @@
  *         and should <b>not</b> be used for cryptographic systems or in any
  *         other situation where true random numbers are required.
  *         <p>
- *         <!-- Creative Commons License --> <a
- *         href="http://creativecommons.org/licenses/LGPL/2.1/"><img
- *         alt="CC-GNU LGPL" border="0"
- *         src="http://creativecommons.org/images/public/cc-LGPL-a.png" /></a><br />
- *         This software is licensed under the <a
- *         href="http://creativecommons.org/licenses/LGPL/2.1/">CC-GNU LGPL</a>.
- *         <!-- /Creative Commons License -->
+ *         <!-- Creative Commons License -->
+ *         <a href="http://creativecommons.org/licenses/LGPL/2.1/"><img alt=
+ *         "CC-GNU LGPL" border="0" src=
+ *         "http://creativecommons.org/images/public/cc-LGPL-a.png" /></a><br />
+ *         This software is licensed under the
+ *         <a href="http://creativecommons.org/licenses/LGPL/2.1/">CC-GNU
+ *         LGPL</a>. <!-- /Creative Commons License -->
  * 
- *         <!-- <rdf:RDF xmlns="http://web.resource.org/cc/"
- *         xmlns:dc="http://purl.org/dc/elements/1.1/"
- *         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+ *         <!-- <rdf:RDF xmlns="http://web.resource.org/cc/" xmlns:dc=
+ *         "http://purl.org/dc/elements/1.1/" xmlns:rdf=
+ *         "http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  * 
- *         <Work rdf:about=""> <license
- *         rdf:resource="http://creativecommons.org/licenses/LGPL/2.1/" />
- *         <dc:type rdf:resource="http://purl.org/dc/dcmitype/Software" />
+ *         <Work rdf:about="">
+ *         <license rdf:resource="http://creativecommons.org/licenses/LGPL/2.1/"
+ *         /> <dc:type rdf:resource="http://purl.org/dc/dcmitype/Software" />
  *         </Work>
  * 
  *         <License rdf:about="http://creativecommons.org/licenses/LGPL/2.1/">
@@ -233,7 +233,10 @@ public synchronized void setSeed(int[] buf) {
 			throw new IllegalArgumentException("Seed buffer may not be empty");
 		}
 		// ---- Begin Mersenne Twister Algorithm ----
-		int i = 1, j = 0, k = (N > length ? N : length);
+		int i = 1;
+		int j = 0;
+		int k = (N > length ? N : length);
+
 		setSeed(MAGIC_SEED);
 		for (; k > 0; k--) {
 			mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >>> 30)) * MAGIC_FACTOR2)) + buf[j] + j;
@@ -290,7 +293,9 @@ public synchronized void setSeed(int[] buf) {
 	@Override
 	protected synchronized int next(int bits) {
 		// ---- Begin Mersenne Twister Algorithm ----
-		int y, kk;
+		int y;
+		int kk;
+
 		if (mti >= N) { // generate N words at one time
 
 			// In the original C implementation, mti is checked here
@@ -361,7 +366,10 @@ protected synchronized int next(int bits) {
 	 *             if the given byte array is null.
 	 */
 	public static int[] pack(byte[] buf) {
-		int k, blen = buf.length, ilen = ((buf.length + 3) >>> 2);
+		int k;
+		int blen = buf.length;
+		int ilen = ((buf.length + 3) >>> 2);
+		
 		int[] ibuf = new int[ilen];
 		for (int n = 0; n < ilen; n++) {
 			int m = (n + 1) << 2;
diff --git a/opt4j-core/src/main/java/org/opt4j/core/common/random/Rand.java b/opt4j-core/src/main/java/org/opt4j/core/common/random/Rand.java
index 29ed88b3..9d8d4ea9 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/common/random/Rand.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/common/random/Rand.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.core.common.random;
 
 import java.util.Random;
@@ -36,6 +36,8 @@
 @ImplementedBy(RandomDefault.class)
 public abstract class Rand extends Random {
 
+	private static final long serialVersionUID = 1L;
+
 	/**
 	 * Constructs a Rand.
 	 */
@@ -53,6 +55,4 @@ public Rand(long seed) {
 		super(seed);
 	}
 
-	private static final long serialVersionUID = 1L;
-
 }
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/Icons.java b/opt4j-core/src/main/java/org/opt4j/core/config/Icons.java
index 01256bb2..e0a75dd4 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/Icons.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/Icons.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.core.config;
 
 import java.awt.Component;
@@ -186,13 +185,6 @@ public class Icons {
 	 */
 	public static final String TEXT = "icons/text.png";
 
-	/**
-	 * Constructs {@link Icons}.
-	 */
-	public Icons() {
-		super();
-	}
-
 	/**
 	 * Returns the {@link URL} of a file.
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/Property.java b/opt4j-core/src/main/java/org/opt4j/core/config/Property.java
index 40e61ce1..7c237711 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/Property.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/Property.java
@@ -232,7 +232,7 @@ public void setValue(Object value) throws InvocationTargetException {
 	}
 
 	/**
-	 * Sets the value of the property. The property has first to be converted to a the corresponding type.
+	 * Sets the value of the property. The property has first to be converted to the corresponding type.
 	 * 
 	 * @param value
 	 *            the value to set
@@ -241,6 +241,7 @@ public void setValue(Object value) throws InvocationTargetException {
 	 */
 	public void setValue(String value) throws InvocationTargetException {
 		Class<?> type = this.type;
+		String valueToSet = value;
 
 		if (type.equals(Integer.TYPE)) {
 			type = Integer.class;
@@ -256,19 +257,19 @@ public void setValue(String value) throws InvocationTargetException {
 			type = Byte.class;
 		} else if (type.equals(Short.TYPE)) {
 			type = Short.class;
-		} else if (type.equals(String.class) && value == null) {
-			value = "";
+		} else if (type.equals(String.class) && valueToSet == null) {
+			valueToSet = "";
 		}
 
 		Object object = null;
 		try {
 			if (Character.TYPE.equals(type) || Character.class.equals(type)) {
-				object = value.toCharArray()[0];
+				object = valueToSet.toCharArray()[0];
 			} else if (type.isEnum()) {
-				object = PropertyModule.toEnumElement(value, type.asSubclass(Enum.class));
+				object = PropertyModule.toEnumElement(valueToSet, type.asSubclass(Enum.class));
 			} else if (type.equals(Class.class)) {
-				if (value != null && !value.equals("")) {
-					Class<?> c = Class.forName(value);
+				if (valueToSet != null && !valueToSet.equals("")) {
+					Class<?> c = Class.forName(valueToSet);
 
 					Type gtype = getter.getGenericReturnType();
 					Type actual = getEnclosingType(gtype);
@@ -284,7 +285,7 @@ public void setValue(String value) throws InvocationTargetException {
 				// and all objects that have a constructor that accepts one
 				// string
 				Constructor<?> constructor = type.getConstructor(String.class);
-				object = constructor.newInstance(value.trim());
+				object = constructor.newInstance(valueToSet.trim());
 			}
 		} catch (Exception e) {
 			Throwable t = e;
@@ -295,7 +296,7 @@ public void setValue(String value) throws InvocationTargetException {
 
 			throw new InvocationTargetException(e,
 					"Failed assignment: module=" + module.getClass().getName() + " property=\"" + getName()
-							+ "\" value=\"" + value + "\" (" + t.getClass().getName()
+							+ "\" value=\"" + valueToSet + "\" (" + t.getClass().getName()
 							+ (message != null ? ": " + message : "") + ")");
 		}
 		setValueObject(object);
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/PropertyModule.java b/opt4j-core/src/main/java/org/opt4j/core/config/PropertyModule.java
index f8547114..12f0913f 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/PropertyModule.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/PropertyModule.java
@@ -209,7 +209,7 @@ public PropertyModule(Module module) {
 
 					Property p = getProperty(required.property());
 					if (p == null) {
-						throw new NullPointerException("Unknown property " + required.property() + " in annotation "
+						throw new IllegalArgumentException("Unknown property " + required.property() + " in annotation "
 								+ required + " in module " + this.getClass());
 					}
 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/ClipboardFrame.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/ClipboardFrame.java
index c40edba8..75361ebf 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/ClipboardFrame.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/ClipboardFrame.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.core.config.visualization;
 
 import java.awt.BorderLayout;
@@ -72,8 +72,14 @@ public void processMouseEvent(MouseEvent me) {
 						StringSelection stringSelection = new StringSelection(content);
 						Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
 						clipboard.setContents(stringSelection, ClipboardFrame.this);
+						break;
+					default:
+						break;
 					}
 					ClipboardFrame.this.dispose();
+					break;
+				default:
+					break;
 				}
 			}
 		};
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Configurator.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Configurator.java
index 326b58f1..a182a531 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Configurator.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Configurator.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.core.config.visualization;
 
@@ -70,7 +69,7 @@ public void start(String[] args) throws ClassNotFoundException {
 		String filename = null;
 		Class<? extends Task> taskClass = null;
 		if (args.length < 1) {
-			throw new RuntimeException("Specify the task class");
+			throw new IllegalArgumentException("Specify the task class");
 		}
 
 		String taskname = args[0];
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultModulesPanel.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultModulesPanel.java
index a361626c..ccf5de47 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultModulesPanel.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultModulesPanel.java
@@ -257,7 +257,10 @@ public Component getTreeCellRendererComponent(JTree tree, Object value, boolean
 	 */
 	protected static class MyTree extends JTree implements DragGestureListener {
 
-		DragSource dragSource = null;
+		protected DragSource dragSource = null;
+		
+		protected DragSourceListener dragSourceListener = new DragSourceAdapter() {
+		};
 
 		public MyTree(TreeNode root) {
 			super(root);
@@ -266,9 +269,6 @@ public MyTree(TreeNode root) {
 			dragSource.createDefaultDragGestureRecognizer(this, DnDConstants.ACTION_MOVE, this);
 		}
 
-		protected DragSourceListener dragSourceListener = new DragSourceAdapter() {
-		};
-
 		@Override
 		public void dragGestureRecognized(DragGestureEvent dge) {
 			TreeNode node = (TreeNode) this.getLastSelectedPathComponent();
@@ -370,7 +370,7 @@ protected void populateTree() {
 
 		for (Class<? extends Module> module : allModules) {
 			Class<?> category = getCategory(module, false);
-			assert (module != category) : module;
+			assert (!module.equals(category)) : module;
 			map.put(module, category);
 		}
 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultSelectedPanel.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultSelectedPanel.java
index be3608d9..d9c699eb 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultSelectedPanel.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultSelectedPanel.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.core.config.visualization;
 
@@ -82,9 +81,50 @@
 @SuppressWarnings("serial")
 public class DefaultSelectedPanel extends SelectedPanel implements SetListener {
 
+	protected final TabbedPane tabs = new TabbedPane();
+
+	protected final Format format;
+
+	protected final SelectedModules selectedModules;
+
+	protected final FileChooser fileChooser;
+
+	protected final Map<PropertyModule, PropertyPanel> map = new HashMap<PropertyModule, PropertyPanel>();
+
+	protected final DropTarget dropTarget;
+
+	/**
+	 * The drop listener for the drag-and-drop functionality.
+	 */
+	protected final DropTargetListener dropListener = new DropTargetAdapter() {
+		@Override
+		public void drop(DropTargetDropEvent dtde) {
+			Transferable transferable = dtde.getTransferable();
+			DataFlavor flaver = ModuleTransferable.localModuleFlavor;
+			try {
+
+				if (transferable.isDataFlavorSupported(flaver)) {
+					Object o = transferable.getTransferData(flaver);
+					PropertyModule module = (PropertyModule) o;
+					selectedModules.add(module);
+
+					dtde.acceptDrop(DnDConstants.ACTION_MOVE);
+					dtde.getDropTargetContext().dropComplete(true);
+				} else {
+					dtde.rejectDrop();
+				}
+
+			} catch (UnsupportedFlavorException e) {
+				e.printStackTrace();
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+		}
+	};
+
 	protected static class MyScrollPane extends JScrollPane {
 
-		PropertyPanel panel;
+		protected PropertyPanel panel;
 
 		public MyScrollPane(PropertyPanel panel) {
 			super(panel);
@@ -158,9 +198,10 @@ public TabComponent(PropertyModule module) {
 
 		protected void setLabelName(String name) {
 			if (name.length() > 22) {
-				name = name.substring(0, 18) + "...";
+				label.setName(name.substring(0, 18) + "...");
+			} else {
+				label.setName(name);
 			}
-			label.setName(name);
 			removeAll();
 
 			label = new JLabel(label.getName(), label.getIcon(), SwingConstants.LEFT);
@@ -270,47 +311,6 @@ public void mouseExited(MouseEvent e) {
 		};
 	}
 
-	protected final TabbedPane tabs = new TabbedPane();
-
-	protected final Format format;
-
-	protected final SelectedModules selectedModules;
-
-	protected final FileChooser fileChooser;
-
-	protected final Map<PropertyModule, PropertyPanel> map = new HashMap<PropertyModule, PropertyPanel>();
-
-	protected final DropTarget dropTarget;
-
-	/**
-	 * The drop listener for the drag-and-drop functionality.
-	 */
-	protected final DropTargetListener dropListener = new DropTargetAdapter() {
-		@Override
-		public void drop(DropTargetDropEvent dtde) {
-			Transferable transferable = dtde.getTransferable();
-			DataFlavor flaver = ModuleTransferable.localModuleFlavor;
-			try {
-
-				if (transferable.isDataFlavorSupported(flaver)) {
-					Object o = transferable.getTransferData(flaver);
-					PropertyModule module = (PropertyModule) o;
-					selectedModules.add(module);
-
-					dtde.acceptDrop(DnDConstants.ACTION_MOVE);
-					dtde.getDropTargetContext().dropComplete(true);
-				} else {
-					dtde.rejectDrop();
-				}
-
-			} catch (UnsupportedFlavorException e) {
-				e.printStackTrace();
-			} catch (IOException e) {
-				e.printStackTrace();
-			}
-		}
-	};
-
 	/**
 	 * Constructs a {@link DefaultSelectedPanel}.
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultTasksPanel.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultTasksPanel.java
index 4153230b..7b8e0301 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultTasksPanel.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DefaultTasksPanel.java
@@ -105,6 +105,8 @@ public Component prepareRenderer(TableCellRenderer renderer, int row, int column
 	 * The {@link Model}.
 	 */
 	protected class Model extends AbstractTableModel {
+		
+		protected String[] columnNames = { "Task", "State" };
 
 		@Override
 		public int getColumnCount() {
@@ -130,8 +132,6 @@ public Object getValueAt(int row, int column) {
 			return null;
 		}
 
-		protected String[] columnNames = { "Task", "State" };
-
 		@Override
 		public String getColumnName(int i) {
 			return columnNames[i];
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DialogLayout.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DialogLayout.java
index 21e75232..14106cb1 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DialogLayout.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/DialogLayout.java
@@ -75,6 +75,7 @@ public DialogLayout(int hGap, int vGap) {
 	 */
 	@Override
 	public void addLayoutComponent(String name, Component comp) {
+		// nothing to be done
 	}
 
 	/*
@@ -84,6 +85,7 @@ public void addLayoutComponent(String name, Component comp) {
 	 */
 	@Override
 	public void removeLayoutComponent(Component comp) {
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/FileOperations.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/FileOperations.java
index 68dae413..a6479560 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/FileOperations.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/FileOperations.java
@@ -47,6 +47,16 @@
  */
 @Singleton
 public class FileOperations {
+	
+	protected File file = null;
+
+	protected final FileChooser fileChooser;
+
+	protected final ModuleRegister moduleRegister;
+
+	protected final SelectedModules selectedModules;
+
+	protected final Set<FileOperationsListener> listeners = new CopyOnWriteArraySet<FileOperationsListener>();
 
 	/**
 	 * The {@link FileOperationsListener}.
@@ -65,16 +75,6 @@ public interface FileOperationsListener {
 		public void setCurrentFile(File file);
 	}
 
-	protected File file = null;
-
-	protected final FileChooser fileChooser;
-
-	protected final ModuleRegister moduleRegister;
-
-	protected final SelectedModules selectedModules;
-
-	protected final Set<FileOperationsListener> listeners = new CopyOnWriteArraySet<FileOperationsListener>();
-
 	/**
 	 * Constructs a {@link FileOperations}.
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Menu.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Menu.java
index b67f9a86..737b3b48 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Menu.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/Menu.java
@@ -48,13 +48,13 @@
 @SuppressWarnings("serial")
 public class Menu extends JMenuBar implements FileOperationsListener, Startupable {
 
-	final JMenuItem load = new JMenuItem("Load ...", Icons.getIcon(Icons.FOLDER));
+	protected final JMenuItem load = new JMenuItem("Load ...", Icons.getIcon(Icons.FOLDER));
 
-	final JMenuItem save = new JMenuItem("Save", Icons.getIcon(Icons.DISK));
+	protected final JMenuItem save = new JMenuItem("Save", Icons.getIcon(Icons.DISK));
 
-	final JMenuItem saveAs = new JMenuItem("Save As ...", Icons.getIcon(Icons.DISK));
+	protected final JMenuItem saveAs = new JMenuItem("Save As ...", Icons.getIcon(Icons.DISK));
 
-	final JMenuItem about = new JMenuItem("About");
+	protected final JMenuItem about = new JMenuItem("About");
 
 	protected final FileOperations fileOperations;
 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/PropertyPanel.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/PropertyPanel.java
index d6a53107..0637f195 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/PropertyPanel.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/PropertyPanel.java
@@ -199,23 +199,24 @@ public void keyReleased(KeyEvent e) {
 	}
 
 	protected String format(Property property, String value) {
+		String result = value;
 		if (property.isNumber()) {
-			value = value.trim();
-			if (value.equals("")) {
-				value = "0";
-			} else if (value.equals("-")) {
-				value = "0";
+			result = result.trim();
+			if ("".equals(result)) {
+				result = "0";
+			} else if ("-".equals(result)) {
+				result = "0";
 			} else {
-				if (value.startsWith(".")) {
-					value = "0" + value;
+				if (result.startsWith(".")) {
+					result = "0" + result;
 				}
-				if (value.endsWith(".")) {
-					value = value + "0";
+				if (result.endsWith(".")) {
+					result = result + "0";
 				}
 			}
-			return value;
+			return result;
 		}
-		return value;
+		return result;
 	}
 
 	protected void fillComponentsMap() {
@@ -311,18 +312,22 @@ protected void addReferenceRow(Citation citation) {
 
 				@Override
 				public void mouseReleased(MouseEvent e) {
+					// nothing to be done
 				}
 
 				@Override
 				public void mousePressed(MouseEvent e) {
+					// nothing to be done
 				}
 
 				@Override
 				public void mouseExited(MouseEvent e) {
+					// nothing to be done
 				}
 
 				@Override
 				public void mouseEntered(MouseEvent e) {
+					// nothing to be done
 				}
 
 				@Override
diff --git a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/SelectedModules.java b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/SelectedModules.java
index 00e4f206..f3601766 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/config/visualization/SelectedModules.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/config/visualization/SelectedModules.java
@@ -46,13 +46,6 @@ public class SelectedModules extends TreeSet<PropertyModule> {
 
 	protected Set<SetListener> listeners = new CopyOnWriteArraySet<SetListener>();
 
-	/**
-	 * Constructs a new, empty {@link SelectedModules} set.
-	 */
-	public SelectedModules() {
-		super();
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanGenotype.java b/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanGenotype.java
index f863328a..81ea0cbc 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanGenotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanGenotype.java
@@ -52,12 +52,6 @@
 @SuppressWarnings("serial")
 public class BooleanGenotype extends ArrayList<Boolean> implements ListGenotype<Boolean> {
 
-	/**
-	 * Constructs a {@link BooleanGenotype}.
-	 */
-	public BooleanGenotype() {
-		super();
-	}
 
 	/*
 	 * (non-Javadoc)
diff --git a/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanMapGenotype.java b/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanMapGenotype.java
index 6c125ab2..b5f66028 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanMapGenotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/genotype/BooleanMapGenotype.java
@@ -63,6 +63,8 @@ public class BooleanMapGenotype<K> extends BooleanGenotype implements MapGenotyp
 
 	protected final List<K> list;
 
+	private static final long serialVersionUID = 1L;
+
 	/**
 	 * Constructs a {@link BooleanMapGenotype}.
 	 * 
@@ -181,14 +183,12 @@ public String toString() {
 	 */
 	@Override
 	public int getIndexOf(K key) {
-		if (!containsKey(key)){
+		if (!containsKey(key)) {
 			throw new IllegalArgumentException(ERROR_MESSAGE_INVALID_KEY);
 		}
 		return list.indexOf(key);
 	}
 
-	private static final long serialVersionUID = 1L;
-
 	/*
 	 * (non-Javadoc)
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/genotype/DoubleMapGenotype.java b/opt4j-core/src/main/java/org/opt4j/core/genotype/DoubleMapGenotype.java
index fd3dcd19..5fab70e4 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/genotype/DoubleMapGenotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/genotype/DoubleMapGenotype.java
@@ -63,6 +63,8 @@
 public class DoubleMapGenotype<K> extends DoubleGenotype implements MapGenotype<K, Double> {
 
 	protected final List<K> keys;
+	
+	private static final long serialVersionUID = 1L;
 
 	/**
 	 * Constructs a {@link DoubleMapGenotype}.
@@ -190,8 +192,6 @@ public int getIndexOf(K key) {
 		return keys.indexOf(key);
 	}
 
-	private static final long serialVersionUID = 1L;
-
 	/*
 	 * (non-Javadoc)
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerGenotype.java b/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerGenotype.java
index d3a70346..a752a396 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerGenotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerGenotype.java
@@ -25,7 +25,8 @@
 
 /**
  * <p>
- * The {@link IntegerGenotype} is a {@link Genotype} that consists of {@link Integer} values.
+ * The {@link IntegerGenotype} is a {@link Genotype} that consists of
+ * {@link Integer} values.
  * </p>
  * <p>
  * Example problem: Select the outcome of throwing five dice<br/>
@@ -47,8 +48,11 @@ public class IntegerGenotype extends ArrayList<Integer> implements ListGenotype<
 
 	protected final Bounds<Integer> bounds;
 
+	private static final long serialVersionUID = 1L;
+
 	/**
-	 * Constructs a {@link IntegerGenotype} with a specified lower and upper bound for all values.
+	 * Constructs a {@link IntegerGenotype} with a specified lower and upper
+	 * bound for all values.
 	 * 
 	 * @param lowerBound
 	 *            the lower bound
@@ -136,6 +140,4 @@ public void init(Random random, int n) {
 			}
 		}
 	}
-
-	private static final long serialVersionUID = 1L;
 }
diff --git a/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerMapGenotype.java b/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerMapGenotype.java
index 2ac00fdb..c70b7da3 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerMapGenotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/genotype/IntegerMapGenotype.java
@@ -60,6 +60,8 @@ public class IntegerMapGenotype<K> extends IntegerGenotype implements MapGenotyp
 
 	protected final List<K> list;
 
+	private static final long serialVersionUID = 1L;
+
 	/**
 	 * Constructs a {@link IntegerMapGenotype}.
 	 * 
@@ -209,8 +211,6 @@ public int getIndexOf(K key) {
 		return list.indexOf(key);
 	}
 
-	private static final long serialVersionUID = 1L;
-
 	/*
 	 * (non-Javadoc)
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/genotype/SelectMapGenotype.java b/opt4j-core/src/main/java/org/opt4j/core/genotype/SelectMapGenotype.java
index aa4040d8..8f535347 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/genotype/SelectMapGenotype.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/genotype/SelectMapGenotype.java
@@ -66,6 +66,8 @@
  */
 public class SelectMapGenotype<K, V> extends IntegerGenotype implements MapGenotype<K, V> {
 
+	private static final long serialVersionUID = 1L;
+	
 	protected final List<K> keys;
 	protected final Map<K, List<V>> values;
 
@@ -251,8 +253,6 @@ public String toString() {
 		return s + "]";
 	}
 
-	private static final long serialVersionUID = 1L;
-
 	/*
 	 * (non-Javadoc)
 	 * 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/start/Opt4J.java b/opt4j-core/src/main/java/org/opt4j/core/start/Opt4J.java
index 28b73a98..45b1d8c5 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/start/Opt4J.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/start/Opt4J.java
@@ -84,7 +84,7 @@ public static String getDateISO() {
 
 	static class SplashDecorator {
 
-		DelayTask delay = new DelayTask(1);
+		protected DelayTask delay = new DelayTask(1);
 
 		protected SplashScreen splash;
 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTask.java b/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTask.java
index c209adeb..3dd19616 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTask.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTask.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.core.start;
 
 import java.lang.reflect.Type;
@@ -130,7 +130,7 @@ public synchronized void close() {
 	public synchronized void open() {
 		if (injector == null && !isClosed) {
 			if (!isInit) {
-				throw new RuntimeException("Task is not initialized. Call method init(modules) first.");
+				throw new IllegalStateException("Task is not initialized. Call method init(modules) first.");
 			}
 			if (parentInjector == null) {
 				injector = Guice.createInjector(modules);
@@ -208,14 +208,30 @@ private void check(Injector injector) {
 			evaluators = injector.getInstance(Key.get(new TypeLiteral<Set<Evaluator<Object>>>() {
 			}));
 		} catch (Exception e) {
-			throw new RuntimeException("Problem configuration Exception: \n" + e.getLocalizedMessage(), e);
+			throw new IllegalStateException("Problem configuration Exception: \n" + e.getLocalizedMessage(), e);
 		}
 		try {
 			injector.getInstance(Optimizer.class);
 		} catch (Exception e) {
-			throw new RuntimeException("Optimizer configuration Exception: \n" + e.getLocalizedMessage(), e);
+			throw new IllegalStateException("Optimizer configuration Exception: \n" + e.getLocalizedMessage(), e);
 		}
 
+		checkInjectedCreatorDecoderEvaluators(creator, decoder, evaluators);
+	}
+
+	/**
+	 * Helper function for check() to check the injected creator, decoder, and
+	 * evaluators.
+	 * 
+	 * @param creator
+	 *            the creator
+	 * @param decoder
+	 *            the decoder
+	 * @param evaluators
+	 *            the set of evaluators
+	 */
+	private void checkInjectedCreatorDecoderEvaluators(Creator<Genotype> creator, Decoder<Genotype, Object> decoder,
+			Set<Evaluator<Object>> evaluators) {
 		try {
 
 			Type creatorType0 = Parameters.getType(Creator.class, creator, "G");
@@ -267,7 +283,7 @@ private void check(Injector injector) {
 	 * optimizer.Control.State)
 	 */
 	@Override
-	public void stateChanged(org.opt4j.core.optimizer.Control.State state) {
+	public void stateChanged(Control.State state) {
 		stateChanged();
 	}
 
diff --git a/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTasksPanel.java b/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTasksPanel.java
index fd873536..50b1503c 100644
--- a/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTasksPanel.java
+++ b/opt4j-core/src/main/java/org/opt4j/core/start/Opt4JTasksPanel.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.core.start;
 
 import java.awt.Color;
@@ -82,8 +82,8 @@ public ProgressRenderer() {
 		}
 
 		@Override
-		public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
-				boolean hasFocus, int row, int column) {
+		public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus,
+				int row, int column) {
 			if (value instanceof Progress) {
 				Progress progress = (Progress) value;
 				Double v = progress.get();
@@ -103,9 +103,8 @@ class Table extends JTable {
 		/*
 		 * (non-Javadoc)
 		 * 
-		 * @see
-		 * javax.swing.JTable#prepareRenderer(javax.swing.table.TableCellRenderer
-		 * , int, int)
+		 * @see javax.swing.JTable#prepareRenderer(javax.swing.table.
+		 * TableCellRenderer , int, int)
 		 */
 		@Override
 		public Component prepareRenderer(TableCellRenderer renderer, int row, int column) {
@@ -299,7 +298,7 @@ public void mouseReleased(MouseEvent e) {
 		 * @param event
 		 *            the triggered event
 		 */
-		void display(MouseEvent event) {
+		protected void display(MouseEvent event) {
 
 			if (event.isPopupTrigger()) {
 				try {
@@ -418,6 +417,9 @@ public void actionPerformed(ActionEvent e) {
 					pause.setEnabled(false);
 					stop.setEnabled(false);
 					break;
+				default:
+					throw new IllegalArgumentException(
+							"Control state " + control.getState() + " not supported by " + this);
 				}
 			} else {
 				terminate.setEnabled(false);
diff --git a/opt4j-core/src/test/java/org/opt4j/common/random/RandomTest.java b/opt4j-core/src/test/java/org/opt4j/common/random/RandomTest.java
index df00b0be..73de1966 100644
--- a/opt4j-core/src/test/java/org/opt4j/common/random/RandomTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/common/random/RandomTest.java
@@ -23,6 +23,7 @@
 
 import static org.junit.Assert.assertEquals;
 
+import org.junit.Assert;
 import org.junit.Test;
 import org.opt4j.core.common.random.Rand;
 import org.opt4j.core.common.random.RandomJava;
@@ -36,17 +37,17 @@ public class RandomTest {
 	public void testConsistencyRandomMersenneTwister() {
 		RandomMersenneTwister r0 = new RandomMersenneTwister(123);
 		RandomMersenneTwister r1 = new RandomMersenneTwister(123);
-		testConsistency(r0, r1);
+		Assert.assertTrue(testConsistency(r0, r1));
 	}
 
 	@Test
 	public void testConsistencyRandomJava() {
 		RandomJava r0 = new RandomJava(123);
 		RandomJava r1 = new RandomJava(123);
-		testConsistency(r0, r1);
+		Assert.assertTrue(testConsistency(r0, r1));
 	}
 
-	public void testConsistency(Rand r0, Rand r1) {
+	public boolean testConsistency(Rand r0, Rand r1) {
 		for (int i = 0; i < SAMPLES; i++) {
 			assertEquals(r0.nextDouble(), r1.nextDouble(), 0.0);
 		}
@@ -68,5 +69,7 @@ public void testConsistency(Rand r0, Rand r1) {
 		for (int i = 0; i < SAMPLES; i++) {
 			assertEquals(r0.nextGaussian(), r1.nextGaussian(), 0.0);
 		}
+
+		return true;
 	}
 }
diff --git a/opt4j-core/src/test/java/org/opt4j/core/AbstractIndividualFactoryTest.java b/opt4j-core/src/test/java/org/opt4j/core/AbstractIndividualFactoryTest.java
index ac5f36a4..d9ce0d83 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/AbstractIndividualFactoryTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/AbstractIndividualFactoryTest.java
@@ -8,10 +8,10 @@
 
 public abstract class AbstractIndividualFactoryTest {
 
-	IndividualStateListener listener = new IndividualStateListener() {
+	protected IndividualStateListener listener = new IndividualStateListener() {
 		@Override
 		public void inidividualStateChanged(Individual individual) {
-
+			// nothing to be done
 		}
 	};
 
diff --git a/opt4j-core/src/test/java/org/opt4j/core/DefaultIndividualFactoryTest.java b/opt4j-core/src/test/java/org/opt4j/core/DefaultIndividualFactoryTest.java
index 506b586f..d76162e7 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/DefaultIndividualFactoryTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/DefaultIndividualFactoryTest.java
@@ -6,8 +6,8 @@
 import com.google.inject.Provider;
 
 public class DefaultIndividualFactoryTest extends AbstractIndividualFactoryTest {
-	Individual individual = new Individual();
-	PermutationGenotype<Object> genotype = new PermutationGenotype<Object>();
+	protected Individual individual = new Individual();
+	protected PermutationGenotype<Object> genotype = new PermutationGenotype<Object>();
 
 	@Override
 	public AbstractIndividualFactory<Individual> getFactory() {
diff --git a/opt4j-core/src/test/java/org/opt4j/core/IndividiualSetTest.java b/opt4j-core/src/test/java/org/opt4j/core/IndividiualSetTest.java
index a449e3a7..ce20ee7d 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/IndividiualSetTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/IndividiualSetTest.java
@@ -20,8 +20,8 @@ public void addTest() {
 	}
 
 	private class AddIndividualSetListener implements IndividualSetListener {
-		IndividualSet collection;
-		Individual i;
+		protected IndividualSet collection;
+		protected Individual i;
 
 		@Override
 		public void individualRemoved(IndividualSet collection, Individual i) {
@@ -76,6 +76,7 @@ public void individualRemoved(IndividualSet collection, Individual i) {
 
 			@Override
 			public void individualAdded(IndividualSet collection, Individual individual) {
+				// nothing to be done
 			}
 		};
 		set.addListener(l);
@@ -102,10 +103,12 @@ public void addListenerTest() {
 		IndividualSetListener l = new IndividualSetListener() {
 			@Override
 			public void individualRemoved(IndividualSet collection, Individual individual) {
+				// nothing to be done
 			}
 
 			@Override
 			public void individualAdded(IndividualSet collection, Individual individual) {
+				// nothing to be done
 			}
 		};
 		set.addListener(l);
@@ -176,8 +179,8 @@ public void isEmptyTest() {
 	}
 
 	private class RemoveIndividualSetListener implements IndividualSetListener {
-		IndividualSet collection;
-		Individual individual;
+		protected IndividualSet collection;
+		protected Individual individual;
 
 		@Override
 		public void individualRemoved(IndividualSet collection, Individual individual) {
diff --git a/opt4j-core/src/test/java/org/opt4j/core/IndividualSetTest.java b/opt4j-core/src/test/java/org/opt4j/core/IndividualSetTest.java
index e0be9014..7758d9bd 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/IndividualSetTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/IndividualSetTest.java
@@ -35,7 +35,7 @@ public class IndividualSetTest {
 
 	protected final static int SIZE = 10000;
 
-	List<Individual> list = new ArrayList<Individual>();
+	protected List<Individual> list = new ArrayList<Individual>();
 
 	@Before
 	public void setUp() throws Exception {
diff --git a/opt4j-core/src/test/java/org/opt4j/core/IndividualTest.java b/opt4j-core/src/test/java/org/opt4j/core/IndividualTest.java
index 71751169..a137cbd9 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/IndividualTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/IndividualTest.java
@@ -8,6 +8,9 @@
 import org.opt4j.core.genotype.PermutationGenotype;
 
 public class IndividualTest {
+	
+	private boolean stateChanged = false;
+	
 	@Test
 	public void getPhenotypeTest() {
 		Individual individual = new Individual();
@@ -37,8 +40,6 @@ public void getObjectivesTest() {
 		Assert.assertTrue(individual.isEvaluated());
 	}
 
-	private boolean stateChanged = false;
-
 	@Test
 	public void setStateTest() {
 		Individual individual = new Individual();
diff --git a/opt4j-core/src/test/java/org/opt4j/core/common/archive/AbstractArchiveTest.java b/opt4j-core/src/test/java/org/opt4j/core/common/archive/AbstractArchiveTest.java
index c18ceeb8..d82f8e2b 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/common/archive/AbstractArchiveTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/common/archive/AbstractArchiveTest.java
@@ -18,7 +18,7 @@
 public class AbstractArchiveTest {
 
 	class TestArchive extends AbstractArchive {
-		Collection<Individual> candidates = null;
+		protected Collection<Individual> candidates = null;
 
 		@Override
 		protected boolean updateWithNondominated(Collection<Individual> candidates) {
diff --git a/opt4j-core/src/test/java/org/opt4j/core/common/archive/CrowdingArchiveTest.java b/opt4j-core/src/test/java/org/opt4j/core/common/archive/CrowdingArchiveTest.java
index ded7859f..1b30bbae 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/common/archive/CrowdingArchiveTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/common/archive/CrowdingArchiveTest.java
@@ -42,8 +42,8 @@ public class CrowdingArchiveTest {
 
 	protected final static int SIZE = 200;
 
-	Set<Individual> set = new HashSet<Individual>();
-	CrowdingArchive crowdingArchive = null;
+	protected Set<Individual> set = new HashSet<Individual>();
+	protected CrowdingArchive crowdingArchive = null;
 
 	protected static class MockProblem implements Creator<Genotype>, Decoder<Genotype, Object>, Evaluator<Object> {
 		@Override
diff --git a/opt4j-core/src/test/java/org/opt4j/core/config/PropertyTest.java b/opt4j-core/src/test/java/org/opt4j/core/config/PropertyTest.java
index a88543bc..92592022 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/config/PropertyTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/config/PropertyTest.java
@@ -316,6 +316,7 @@ public void setMockEnum(MyEnum i) {
 
 		@Override
 		public void configure(Binder binder) {
+			// nothing to be done
 		}
 	}
 
diff --git a/opt4j-core/src/test/java/org/opt4j/core/genotype/DoubleMapGenotypeTest.java b/opt4j-core/src/test/java/org/opt4j/core/genotype/DoubleMapGenotypeTest.java
index 34807a5e..1300d211 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/genotype/DoubleMapGenotypeTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/genotype/DoubleMapGenotypeTest.java
@@ -50,9 +50,7 @@ public boolean equals(Object obj) {
 			MockObject other = (MockObject) obj;
 			if (!getOuterType().equals(other.getOuterType()))
 				return false;
-			if (field != other.field)
-				return false;
-			return true;
+			return field == other.field;
 		}
 		
 		@Override
diff --git a/opt4j-core/src/test/java/org/opt4j/core/genotype/IntegerMapGenotypeTest.java b/opt4j-core/src/test/java/org/opt4j/core/genotype/IntegerMapGenotypeTest.java
index e12d861e..8a82d8e3 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/genotype/IntegerMapGenotypeTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/genotype/IntegerMapGenotypeTest.java
@@ -58,9 +58,7 @@ public boolean equals(Object obj) {
 				return false;
 			if (Double.doubleToLongBits(field1) != Double.doubleToLongBits(other.field1))
 				return false;
-			if (field2 != other.field2)
-				return false;
-			return true;
+			return field2 == other.field2;
 		}
 
 		private IntegerMapGenotypeTest getOuterType() {
diff --git a/opt4j-core/src/test/java/org/opt4j/core/genotype/SelectGenotypeTest.java b/opt4j-core/src/test/java/org/opt4j/core/genotype/SelectGenotypeTest.java
index b59a082b..625732e3 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/genotype/SelectGenotypeTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/genotype/SelectGenotypeTest.java
@@ -54,9 +54,7 @@ public boolean equals(Object obj) {
 				return false;
 			if (Double.doubleToLongBits(field1) != Double.doubleToLongBits(other.field1))
 				return false;
-			if (field2 != other.field2)
-				return false;
-			return true;
+			return field2 == other.field2;
 		}
 
 		private SelectGenotypeTest getOuterType() {
@@ -92,6 +90,7 @@ public void testArrayConstructor() {
 		mockObjects.add(obj3);
 		SelectGenotype<MockObject> selectGenotype = new SelectGenotype<SelectGenotypeTest.MockObject>(inputArray);
 		testGenotype(selectGenotype, mockObjects);
+		assertFalse(selectGenotype.isEmpty());
 	}
 
 	@Test
@@ -110,6 +109,7 @@ public void testListConstructor() {
 		mockObjects.add(obj3);
 		SelectGenotype<MockObject> selectGenotype = new SelectGenotype<SelectGenotypeTest.MockObject>(inputList);
 		testGenotype(selectGenotype, mockObjects);
+		assertFalse(selectGenotype.isEmpty());
 	}
 
 }
diff --git a/opt4j-core/src/test/java/org/opt4j/core/optimizer/AbstractOptimizerTest.java b/opt4j-core/src/test/java/org/opt4j/core/optimizer/AbstractOptimizerTest.java
index dd66b50c..cac445d5 100644
--- a/opt4j-core/src/test/java/org/opt4j/core/optimizer/AbstractOptimizerTest.java
+++ b/opt4j-core/src/test/java/org/opt4j/core/optimizer/AbstractOptimizerTest.java
@@ -9,8 +9,13 @@
 import org.opt4j.core.Individual;
 
 public class AbstractOptimizerTest {
+	
+	protected boolean started = false;
+	protected boolean archiveHasRun = false;
+	protected boolean completerHasRun = false;
+	
 	class MockOptimizer extends AbstractOptimizer {
-		TestMethod t;
+		protected TestMethod t;
 
 		public MockOptimizer(Population population, Archive archive, IndividualCompleter completer, Control control,
 				Iteration iteration) {
@@ -78,8 +83,6 @@ public void test() throws TerminationException, StopException {
 		Assert.assertFalse(optimizer.isRunning());
 	}
 
-	boolean started = false;
-
 	@Test
 	public void startOptimizationWithListener() throws TerminationException {
 		final MockOptimizer optimizer = new MockOptimizer(null, null, null, null, null);
@@ -94,6 +97,7 @@ public void optimizationStarted(Optimizer optimizer) {
 
 			@Override
 			public void optimizationStopped(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 		};
@@ -102,15 +106,13 @@ public void optimizationStopped(Optimizer optimizer) {
 		optimizer.setOptimizeTest(new TestMethod() {
 			@Override
 			public void test() throws TerminationException, StopException {
+				// nothing to be done
 			}
 		});
 		optimizer.startOptimization();
 		Assert.assertTrue(started);
 	}
 
-	boolean archiveHasRun = false;
-	boolean completerHasRun = false;
-
 	@Test
 	public void nextIteration() throws TerminationException {
 		final Control c = new Control();
@@ -172,10 +174,12 @@ public boolean update(Set<? extends Individual> individuals) {
 
 			@Override
 			public void complete(Individual... individuals) throws TerminationException {
+				// nothing to be done
 			}
 
 			@Override
 			public void complete(Iterable<? extends Individual> iterable) throws TerminationException {
+				// nothing to be done
 			}
 		};
 		final MockOptimizer optimizer = new MockOptimizer(p, a, completer, c, new Iteration(10));
@@ -215,10 +219,12 @@ public boolean update(Set<? extends Individual> individuals) {
 		}, new IndividualCompleter() {
 			@Override
 			public void complete(Individual... individuals) throws TerminationException {
+				// nothing to be done
 			}
 
 			@Override
 			public void complete(Iterable<? extends Individual> iterable) throws TerminationException {
+				// nothing to be done
 			}
 		}, c, new Iteration(4));
 		Assert.assertFalse(optimizer.isRunning());
@@ -241,6 +247,7 @@ public void addOptimizerIterationListener() {
 		OptimizerIterationListener l = new OptimizerIterationListener() {
 			@Override
 			public void iterationComplete(int iteration) {
+				// nothing to be done
 			}
 		};
 		optimizer.addOptimizerIterationListener(l);
@@ -255,10 +262,12 @@ public void addOptimizerStateListener() {
 		OptimizerStateListener l = new OptimizerStateListener() {
 			@Override
 			public void optimizationStarted(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 			@Override
 			public void optimizationStopped(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 		};
@@ -274,6 +283,7 @@ public void removeOptimizerIterationListener() {
 		OptimizerIterationListener l = new OptimizerIterationListener() {
 			@Override
 			public void iterationComplete(int iteration) {
+				// nothing to be done
 			}
 		};
 		optimizer.addOptimizerIterationListener(l);
@@ -287,10 +297,12 @@ public void removeOptimizerStateListener() {
 		OptimizerStateListener l = new OptimizerStateListener() {
 			@Override
 			public void optimizationStarted(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 			@Override
 			public void optimizationStopped(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 		};
@@ -306,15 +318,18 @@ public void injectListeners() {
 		OptimizerIterationListener l1 = new OptimizerIterationListener() {
 			@Override
 			public void iterationComplete(int iteration) {
+				// nothing to be done
 			}
 		};
 		OptimizerStateListener l2 = new OptimizerStateListener() {
 			@Override
 			public void optimizationStarted(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 			@Override
 			public void optimizationStopped(Optimizer optimizer) {
+				// nothing to be done
 			}
 
 		};
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/AbstractGenericOperator.java b/opt4j-operators/src/main/java/org/opt4j/operators/AbstractGenericOperator.java
index 6bbcb9d7..92e9231f 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/AbstractGenericOperator.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/AbstractGenericOperator.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators;
 
@@ -55,8 +54,14 @@
  * @param <Q>
  *            The specified {@link Operator} with a wildcard (?).
  */
-public abstract class AbstractGenericOperator<O extends Operator<?>, Q extends Operator<?>> implements
-		GenericOperator<O> {
+public abstract class AbstractGenericOperator<O extends Operator<?>, Q extends Operator<?>>
+		implements GenericOperator<O> {
+
+	protected SortedMap<Class<? extends Genotype>, O> classOperators = new TreeMap<Class<? extends Genotype>, O>(
+			new ClassComparator());
+	protected Map<OperatorPredicate, O> genericOperators = new HashMap<OperatorPredicate, O>();
+
+	protected List<Class<? extends Q>> cldef = new ArrayList<Class<? extends Q>>();
 
 	/**
 	 * Comparator for a specific order: Superclasses always are sorted after
@@ -89,12 +94,6 @@ public int compare(Class<? extends Genotype> arg0, Class<? extends Genotype> arg
 
 	}
 
-	protected SortedMap<Class<? extends Genotype>, O> classOperators = new TreeMap<Class<? extends Genotype>, O>(
-			new ClassComparator());
-	protected Map<OperatorPredicate, O> genericOperators = new HashMap<OperatorPredicate, O>();
-
-	protected List<Class<? extends Q>> cldef = new ArrayList<Class<? extends Q>>();
-
 	/**
 	 * Constructs an {@link AbstractGenericOperator} class with the given
 	 * clazzes of default operators.
@@ -173,7 +172,8 @@ public O getOperator(Genotype genotype) {
 					return operator;
 				}
 			}
-			throw new IncompatibilityException("No handler found for " + genotype.getClass() + " in " + this.getClass());
+			throw new IncompatibilityException(
+					"No handler found for " + genotype.getClass() + " in " + this.getClass());
 		}
 
 	}
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/BasicCrossoverModule.java b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/BasicCrossoverModule.java
index e8aaa794..3fc269aa 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/BasicCrossoverModule.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/BasicCrossoverModule.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators.crossover;
 
@@ -154,13 +153,6 @@ public enum IntegerType {
 		XPOINT;
 	}
 
-	/**
-	 * Constructs a {@link BasicCrossoverModule}.
-	 */
-	public BasicCrossoverModule() {
-		super();
-	}
-
 	/**
 	 * Returns the rate of the {@link CrossoverIntegerRate}.
 	 * 
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleSBX.java b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleSBX.java
index c41bbbb1..79521697 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleSBX.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleSBX.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.operators.crossover;
 
 import static java.lang.annotation.RetentionPolicy.RUNTIME;
@@ -68,13 +67,13 @@
  */
 public class CrossoverDoubleSBX extends CrossoverDoubleElementwise {
 
+	protected double nu;
+
 	@Retention(RUNTIME)
 	@BindingAnnotation
 	protected @interface Nu {
 	}
 
-	protected double nu;
-
 	/**
 	 * Constructs a {@link CrossoverDoubleSBX} with a nu value and a random
 	 * generator.
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleUnfairAverage.java b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleUnfairAverage.java
index 438e3c85..0d246ee4 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleUnfairAverage.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverDoubleUnfairAverage.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.operators.crossover;
 
 import java.util.List;
@@ -93,7 +92,10 @@ public CrossoverDoubleUnfairAverage(
 	 */
 	@Override
 	protected void crossover(List<Double> p1, List<Double> p2, List<Double> o1, List<Double> o2) {
-		double z1, z2, x, y;
+		double z1;
+		double z2;
+		double x;
+		double y;
 
 		int size = p1.size();
 		int j = random.nextInt(size);
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverListXPoint.java b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverListXPoint.java
index 95b51384..e761a195 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverListXPoint.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverListXPoint.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators.crossover;
 
@@ -82,7 +81,7 @@ public Pair<G> crossover(G p1, G p2) {
 		int size = p1.size();
 
 		if (x <= 0 || x > size - 1) {
-			throw new RuntimeException(this.getClass() + " : x is " + x + " for binary vector size " + size);
+			throw new IllegalArgumentException(this.getClass() + " : x is " + x + " for binary vector size " + size);
 		}
 
 		SortedSet<Integer> points = new TreeSet<Integer>();
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverPermutationOnePoint.java b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverPermutationOnePoint.java
index ab21b02a..c2ba2491 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverPermutationOnePoint.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/crossover/CrossoverPermutationOnePoint.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators.crossover;
 
@@ -104,36 +103,85 @@ public Pair<PermutationGenotype<?>> crossover(PermutationGenotype<?> p1, Permuta
 			Set<Object> elements1 = new HashSet<Object>();
 			Set<Object> elements2 = new HashSet<Object>();
 
-			int offset = rotation ? random.nextInt(size) : 0;
+			crossoverToCutpoint(p1, p2, o1, o2, elements1, elements2);
+			crossoverFill(p1, p2, o1, o2, elements1, elements2);
 
-			int cutpoint = random.nextInt(size);
+		}
 
-			for (int i = 0; i < cutpoint; i++) {
-				final int pos = (offset + i) % size;
-				Object e1 = p1.get(pos);
-				Object e2 = p2.get(pos);
-				o1.add(e1);
-				o2.add(e2);
-				elements1.add(e1);
-				elements2.add(e2);
-			}
+		Pair<PermutationGenotype<?>> offspring = new Pair<PermutationGenotype<?>>(o1, o2);
+		return offspring;
+	}
+
+	/**
+	 * Helper function for crossover() to crossover and rotate up to the coined cut
+	 * point.
+	 * 
+	 * @param p1
+	 *            parent one
+	 * @param p2
+	 *            parent two
+	 * @param o1
+	 *            child one
+	 * @param o2
+	 *            child two
+	 * @param elements1
+	 *            elements of genotype child one
+	 * @param elements2
+	 *            elements of genotype child two
+	 */
+	protected void crossoverToCutpoint(PermutationGenotype<?> p1, PermutationGenotype<?> p2,
+			PermutationGenotype<Object> o1, PermutationGenotype<Object> o2, Set<Object> elements1,
+			Set<Object> elements2) {
+		int size = p1.size();
+		int offset = rotation ? random.nextInt(size) : 0;
+
+		int cutpoint = random.nextInt(size);
+
+		for (int i = 0; i < cutpoint; i++) {
+			final int pos = (offset + i) % size;
+			Object e1 = p1.get(pos);
+			Object e2 = p2.get(pos);
+			o1.add(e1);
+			o2.add(e2);
+			elements1.add(e1);
+			elements2.add(e2);
+		}
 
-			offset = rotation ? random.nextInt(size) : 0;
-
-			for (int i = 0; i < size; i++) {
-				final int pos = (offset + i) % size;
-				Object e1 = p1.get(pos);
-				Object e2 = p2.get(pos);
-				if (!elements1.contains(e2)) {
-					o1.add(e2);
-				}
-				if (!elements2.contains(e1)) {
-					o2.add(e1);
-				}
+	}
+
+	/**
+	 * Helper function for crossover() to fill and rotate after the cut point.
+	 * 
+	 * @param p1
+	 *            parent one
+	 * @param p2
+	 *            parent two
+	 * @param o1
+	 *            child one
+	 * @param o2
+	 *            child two
+	 * @param elements1
+	 *            elements of genotype child one
+	 * @param elements2
+	 *            elements of genotype child two
+	 */
+	protected void crossoverFill(PermutationGenotype<?> p1, PermutationGenotype<?> p2, PermutationGenotype<Object> o1,
+			PermutationGenotype<Object> o2, Set<Object> elements1, Set<Object> elements2) {
+		int size = p1.size();
+		int offset = rotation ? random.nextInt(size) : 0;
+
+		for (int i = 0; i < size; i++) {
+			final int pos = (offset + i) % size;
+			Object e1 = p1.get(pos);
+			Object e2 = p2.get(pos);
+			if (!elements1.contains(e2)) {
+				o1.add(e2);
+			}
+			if (!elements2.contains(e1)) {
+				o2.add(e1);
 			}
 		}
 
-		Pair<PermutationGenotype<?>> offspring = new Pair<PermutationGenotype<?>>(o1, o2);
-		return offspring;
 	}
+
 }
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/mutate/BasicMutateModule.java b/opt4j-operators/src/main/java/org/opt4j/operators/mutate/BasicMutateModule.java
index 074251ac..01caffbe 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/mutate/BasicMutateModule.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/mutate/BasicMutateModule.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators.mutate;
 
@@ -123,13 +122,6 @@ public enum PermutationType {
 		REVERT;
 	}
 
-	/**
-	 * Constructs a {@link BasicMutateModule}.
-	 */
-	public BasicMutateModule() {
-		super();
-	}
-
 	/**
 	 * Returns the {@link MutationRateType}.
 	 * 
@@ -258,6 +250,10 @@ public void config() {
 			break;
 		case CONSTANT:
 			bind(MutationRate.class).to(ConstantMutationRate.class).in(SINGLETON);
+			break;
+		default:
+			bind(MutationRate.class).to(AdaptiveMutationRate.class).in(SINGLETON);
+			break;
 		}
 
 		Class<? extends MutatePermutation> permutation = MutatePermutationMixed.class;
@@ -275,6 +271,8 @@ public void config() {
 		case REVERT:
 			permutation = MutatePermutationRevert.class;
 			break;
+		default:
+			break;
 		}
 		bind(MutatePermutation.class).to(permutation).in(SINGLETON);
 
@@ -285,6 +283,9 @@ public void config() {
 		case POLYNOMIAL:
 			bind(MutateDouble.class).to(MutateDoublePolynomial.class).in(SINGLETON);
 			break;
+		default:
+			bind(MutateDouble.class).to(MutateDoublePolynomial.class).in(SINGLETON);
+			break;
 		}
 	}
 }
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/mutate/MutateDoubleGauss.java b/opt4j-operators/src/main/java/org/opt4j/operators/mutate/MutateDoubleGauss.java
index ab7c4bd2..764ec3db 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/mutate/MutateDoubleGauss.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/mutate/MutateDoubleGauss.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators.mutate;
 
@@ -65,10 +64,11 @@ public MutateDoubleGauss(Rand random, NormalizeDouble normalize,
 	 */
 	@Override
 	protected double mutateElement(double element, double lb, double ub, double p) {
+		double result = element;
 		if (random.nextDouble() < p) {
-			element += sigma * random.nextGaussian();
+			result += sigma * random.nextGaussian();
 		}
-		return element;
+		return result;
 	}
 
 }
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/neighbor/BasicNeighborModule.java b/opt4j-operators/src/main/java/org/opt4j/operators/neighbor/BasicNeighborModule.java
index 215b76a0..463d78e0 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/neighbor/BasicNeighborModule.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/neighbor/BasicNeighborModule.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.operators.neighbor;
 
@@ -86,13 +85,6 @@ public void setPermutationType(PermutationType permutationMode) {
 		this.permutationType = permutationMode;
 	}
 
-	/**
-	 * Constructs a {@link BasicNeighborModule}.
-	 */
-	public BasicNeighborModule() {
-		super();
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * 
@@ -115,6 +107,9 @@ public void config() {
 		case REVERT:
 			permutation = NeighborPermutationRevert.class;
 			break;
+		default:
+			permutation = NeighborPermutationMixed.class;
+			break;
 		}
 		bind(NeighborPermutation.class).to(permutation).in(SINGLETON);
 	}
diff --git a/opt4j-operators/src/main/java/org/opt4j/operators/normalize/NormalizeDoubleWrap.java b/opt4j-operators/src/main/java/org/opt4j/operators/normalize/NormalizeDoubleWrap.java
index a13af819..eea0354e 100644
--- a/opt4j-operators/src/main/java/org/opt4j/operators/normalize/NormalizeDoubleWrap.java
+++ b/opt4j-operators/src/main/java/org/opt4j/operators/normalize/NormalizeDoubleWrap.java
@@ -44,15 +44,16 @@ public class NormalizeDoubleWrap extends NormalizeDoubleElementwise {
 	@Override
 	public double normalize(double value, double lb, double ub) {
 		double diff = ub - lb;
-		if (value < lb) {
-			double distance = lb - value;
-			value += Math.ceil(distance / diff) * diff;
+		double result = value;
+		if (result < lb) {
+			double distance = lb - result;
+			result += Math.ceil(distance / diff) * diff;
 		}
-		if (value > ub) {
-			double distance = value - ub;
-			value -= Math.ceil(distance / diff) * diff;
+		if (result > ub) {
+			double distance = result - ub;
+			result -= Math.ceil(distance / diff) * diff;
 		}
-		return value;
+		return result;
 	}
 
 }
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/BasicMatingModule.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/BasicMatingModule.java
index f76c494c..35572a15 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/BasicMatingModule.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/BasicMatingModule.java
@@ -61,14 +61,6 @@ public enum CouplerType {
 		UNIQUE;
 	}
 
-	/**
-	 * Constructs a {@link BasicMatingModule}.
-	 * 
-	 */
-	public BasicMatingModule() {
-		super();
-	}
-
 	/**
 	 * Returns the type of {@link Coupler} operator to use.
 	 * 
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Hypervolume.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Hypervolume.java
index cb7d73bc..11a5c796 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Hypervolume.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Hypervolume.java
@@ -34,11 +34,13 @@
 import com.google.inject.Inject;
 
 /**
- * The {@link Hypervolume}, see "Zitzler, E., and Thiele, L. (1998): Multiobjective Optimization Using Evolutionary
- * Algorithms - A Comparative Case Study. Parallel Problem Solving from Nature (PPSN-V), 292-301." is a
- * {@link FrontDensityIndicator} based on determination of the hypervolume contribution. The calculation is based on a
- * normalization between 0 and 1 in each dimension and a transformation to a maximization problem. Additionally an
- * offset value (default 1) is added to each dimension.
+ * The {@link Hypervolume}, see "Zitzler, E., and Thiele, L. (1998):
+ * Multiobjective Optimization Using Evolutionary Algorithms - A Comparative
+ * Case Study. Parallel Problem Solving from Nature (PPSN-V), 292-301." is a
+ * {@link FrontDensityIndicator} based on determination of the hypervolume
+ * contribution. The calculation is based on a normalization between 0 and 1 in
+ * each dimension and a transformation to a maximization problem. Additionally
+ * an offset value (default 1) is added to each dimension.
  * 
  * 
  * @see SMSModule
@@ -56,7 +58,8 @@ public class Hypervolume implements FrontDensityIndicator {
 	 * Constructs a {@link Hypervolume}.
 	 * 
 	 * @param offset
-	 *            the offset that is added to each dimension before the hypervolume is calculated
+	 *            the offset that is added to each dimension before the
+	 *            hypervolume is calculated
 	 */
 	@Inject
 	public Hypervolume(@Constant(value = "offset", namespace = Hypervolume.class) double offset) {
@@ -66,7 +69,9 @@ public Hypervolume(@Constant(value = "offset", namespace = Hypervolume.class) do
 	/*
 	 * (non-Javadoc)
 	 * 
-	 * @see org.opt4j.optimizer.ea.FrontDensityIndicator#getDensityValues(java.util .Collection)
+	 * @see
+	 * org.opt4j.optimizer.ea.FrontDensityIndicator#getDensityValues(java.util
+	 * .Collection)
 	 */
 	@Override
 	public Map<Individual, Double> getDensityValues(Collection<Individual> individuals) {
@@ -74,10 +79,11 @@ public Map<Individual, Double> getDensityValues(Collection<Individual> individua
 	}
 
 	/**
-	 * Calculates the density values for a front of non-dominated individuals based on the contribution of the
-	 * {@link Hypervolume}.
+	 * Calculates the density values for a front of non-dominated individuals
+	 * based on the contribution of the {@link Hypervolume}.
 	 * 
-	 * A special approach for two dimension exists as well as a general approach for n dimensions.
+	 * A special approach for two dimension exists as well as a general approach
+	 * for n dimensions.
 	 * 
 	 * @param individuals
 	 *            the individuals
@@ -170,7 +176,8 @@ public int compare(double[] o1, double[] o2) {
 	}
 
 	/**
-	 * Transforms the non-dominated {@link Individual}s to a front where each objective is to be minimized.
+	 * Transforms the non-dominated {@link Individual}s to a front where each
+	 * objective is to be minimized.
 	 * 
 	 * @param individuals
 	 *            the individuals
@@ -225,8 +232,8 @@ protected List<double[]> normalize(List<double[]> front) {
 	}
 
 	/**
-	 * Inverts (from a minimization to a maximization problem) a front of solutions and adds an offset value to each
-	 * dimension.
+	 * Inverts (from a minimization to a maximization problem) a front of
+	 * solutions and adds an offset value to each dimension.
 	 * 
 	 * @param front
 	 *            the front of non-dominated solutions
@@ -253,8 +260,9 @@ protected List<double[]> invert(List<double[]> front, double offset) {
 	}
 
 	/**
-	 * Implements the {@link Hypervolume} calculations as proposed by Zitzler, E., and Thiele, L. (1998). All points
-	 * have positive values in all dimensions and the hypervolume is calculated from 0.
+	 * Implements the {@link Hypervolume} calculations as proposed by Zitzler,
+	 * E., and Thiele, L. (1998). All points have positive values in all
+	 * dimensions and the hypervolume is calculated from 0.
 	 * 
 	 * @param front
 	 *            the front of non-dominated solutions
@@ -278,7 +286,7 @@ protected double calculateHypervolume(List<double[]> front, int nObjectives) {
 			double tempDistance = surfaceUnchangedTo(front, nObjectives - 1);
 			volume += tempVolume * (tempDistance - distance);
 			distance = tempDistance;
-			front = reduceNondominatedSet(front, nObjectives - 1, distance);
+			reduceNondominatedSet(front, nObjectives - 1, distance);
 		}
 
 		return volume;
@@ -331,15 +339,16 @@ protected double surfaceUnchangedTo(List<double[]> front, int objective) {
 		return value;
 	}
 
-	protected List<double[]> reduceNondominatedSet(List<double[]> front, int objective, double threshold) {
-		List<double[]> result = new ArrayList<double[]>();
+	protected void reduceNondominatedSet(List<double[]> front, int objective, double threshold) {
+		List<double[]> lames = new ArrayList<double[]>();
 
 		for (double[] p : front) {
-			if (p[objective] > threshold) {
-				result.add(p);
+			if (p[objective] <= threshold) {
+				lames.add(p);
 			}
 		}
-		return result;
+
+		front.removeAll(lames);
 	}
 
 }
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/MatingCrossoverMutate.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/MatingCrossoverMutate.java
index 37d2f892..82d4e20a 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/MatingCrossoverMutate.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/MatingCrossoverMutate.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.optimizers.ea;
 
 import java.util.ArrayList;
@@ -165,7 +165,8 @@ protected Collection<Individual> getOffspringInternal(int size, Collection<Indiv
 	protected Pair<Individual> mate(Individual parent1, Individual parent2, boolean doCrossover) {
 		Genotype p1 = parent1.getGenotype();
 		Genotype p2 = parent2.getGenotype();
-		Genotype o1, o2;
+		Genotype o1;
+		Genotype o2;
 
 		if (doCrossover) {
 			Pair<Genotype> offspring = crossover.crossover(p1, p2);
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Nsga2.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Nsga2.java
index 9eb6e4cd..e643c1b6 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Nsga2.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Nsga2.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.optimizers.ea;
 
@@ -184,43 +183,27 @@ protected Map<Individual, Integer> getRank(List<List<Individual>> fronts) {
 	 */
 	public List<List<Individual>> fronts(Collection<Individual> individuals) {
 
-		List<Individual> pop = new ArrayList<Individual>(individuals);
-		Map<Individual, Integer> id = new HashMap<Individual, Integer>();
-		for (int i = 0; i < pop.size(); i++) {
-			id.put(pop.get(i), i);
+		List<Individual> population = new ArrayList<Individual>(individuals);
+		Map<Individual, Integer> individualIDs = new HashMap<Individual, Integer>();
+		for (int i = 0; i < population.size(); i++) {
+			individualIDs.put(population.get(i), i);
 		}
 
 		List<List<Individual>> fronts = new ArrayList<List<Individual>>();
 
-		Map<Individual, List<Individual>> S = new HashMap<Individual, List<Individual>>();
-		int[] n = new int[pop.size()];
+		Map<Individual, List<Individual>> dominatedIndividuals = new HashMap<Individual, List<Individual>>();
+		int[] numberOfDominations = new int[population.size()];
 
-		for (Individual e : pop) {
-			S.put(e, new ArrayList<Individual>());
-			n[id.get(e)] = 0;
+		for (Individual e : population) {
+			dominatedIndividuals.put(e, new ArrayList<Individual>());
+			numberOfDominations[individualIDs.get(e)] = 0;
 		}
 
-		for (int i = 0; i < pop.size(); i++) {
-			for (int j = i + 1; j < pop.size(); j++) {
-				Individual p = pop.get(i);
-				Individual q = pop.get(j);
-
-				Objectives po = p.getObjectives();
-				Objectives qo = q.getObjectives();
-
-				if (po.dominates(qo)) {
-					S.get(p).add(q);
-					n[id.get(q)]++;
-				} else if (qo.dominates(po)) {
-					S.get(q).add(p);
-					n[id.get(p)]++;
-				}
-			}
-		}
+		frontsResolveDomination(population, numberOfDominations, individualIDs, dominatedIndividuals);
 
 		List<Individual> f1 = new ArrayList<Individual>();
-		for (Individual i : pop) {
-			if (n[id.get(i)] == 0) {
+		for (Individual i : population) {
+			if (numberOfDominations[individualIDs.get(i)] == 0) {
 				f1.add(i);
 			}
 		}
@@ -229,9 +212,9 @@ public List<List<Individual>> fronts(Collection<Individual> individuals) {
 		while (!fi.isEmpty()) {
 			List<Individual> h = new ArrayList<Individual>();
 			for (Individual p : fi) {
-				for (Individual q : S.get(p)) {
-					n[id.get(q)]--;
-					if (n[id.get(q)] == 0) {
+				for (Individual q : dominatedIndividuals.get(p)) {
+					numberOfDominations[individualIDs.get(q)]--;
+					if (numberOfDominations[individualIDs.get(q)] == 0) {
 						h.add(q);
 					}
 				}
@@ -242,4 +225,38 @@ public List<List<Individual>> fronts(Collection<Individual> individuals) {
 		return fronts;
 	}
 
+	/**
+	 * Helper function for fronts() that determines the number of dominations
+	 * and the dominated individuals for each individual
+	 * 
+	 * @param population
+	 *            the individuals to consider
+	 * @param numberOfDominations
+	 *            the number of dominations
+	 * @param individualID
+	 *            helper ID for the individuals
+	 * @param dominatedIndividuals
+	 *            the individuals dominated by each individual
+	 */
+	protected void frontsResolveDomination(List<Individual> population, int[] numberOfDominations,
+			Map<Individual, Integer> individualID, Map<Individual, List<Individual>> dominatedIndividuals) {
+		for (int i = 0; i < population.size(); i++) {
+			for (int j = i + 1; j < population.size(); j++) {
+				Individual p = population.get(i);
+				Individual q = population.get(j);
+
+				Objectives po = p.getObjectives();
+				Objectives qo = q.getObjectives();
+
+				if (po.dominates(qo)) {
+					dominatedIndividuals.get(p).add(q);
+					numberOfDominations[individualID.get(q)]++;
+				} else if (qo.dominates(po)) {
+					dominatedIndividuals.get(q).add(p);
+					numberOfDominations[individualID.get(p)]++;
+				}
+			}
+		}
+	}
+
 }
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Spea2.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Spea2.java
index 1814b85d..ae2d4221 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Spea2.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/ea/Spea2.java
@@ -43,8 +43,8 @@
 
 /**
  * <p>
- * The {@link Spea2}-Selector is a Java implementation of the <a
- * href="http://e-collection.ethbib.ethz.ch/ecol-pool/incoll/incoll_324.pdf"
+ * The {@link Spea2}-Selector is a Java implementation of the
+ * <a href="http://e-collection.ethbib.ethz.ch/ecol-pool/incoll/incoll_324.pdf"
  * >SPEA2-MOEA</a>, see "SPEA2: Improving the Strength Pareto Evolutionary
  * Algorithm For Multiobjective Optimization, Eckart Zitzler, Marco Laumanns,
  * and Lothar Thiele, In Evolutionary Methods for Design, Optimisation, and
@@ -79,7 +79,8 @@ public class Spea2 implements Selector {
 	 * @author lukasiewycz
 	 * 
 	 */
-	private static class Spea2IndividualSet extends LinkedHashSet<Individual> implements Comparable<Spea2IndividualSet> {
+	private static class Spea2IndividualSet extends LinkedHashSet<Individual>
+			implements Comparable<Spea2IndividualSet> {
 		private static final long serialVersionUID = 1L;
 		protected final int id;
 		protected int fitness;
@@ -338,32 +339,7 @@ protected List<Spea2IndividualSet> getNearest(int n, Collection<Spea2IndividualS
 
 		List<Spea2IndividualSet> lames = new ArrayList<Spea2IndividualSet>();
 
-		Map<Spea2IndividualSet, List<Spea2IndividualSet>> orderedLists = new LinkedHashMap<Spea2IndividualSet, List<Spea2IndividualSet>>();
-
-		for (Spea2IndividualSet w0 : candidates) {
-			List<Spea2IndividualSet> list = new ArrayList<Spea2IndividualSet>();
-			for (Spea2IndividualSet w1 : candidates) {
-				if (w0 != w1) {
-					w1.setNextDistance(distance(w0, w1));
-					list.add(w1);
-				}
-			}
-			Collections.sort(list, new Comparator<Spea2IndividualSet>() {
-				@Override
-				public int compare(Spea2IndividualSet o1, Spea2IndividualSet o2) {
-					double v = o1.getNextDistance() - o2.getNextDistance();
-					if (v < 0) {
-						return -1;
-					} else if (v > 0) {
-						return 1;
-					} else {
-						return 0;
-					}
-				}
-
-			});
-			orderedLists.put(w0, list);
-		}
+		Map<Spea2IndividualSet, List<Spea2IndividualSet>> orderedLists = getNearestPreOrder(candidates);
 
 		while (lames.size() < n) {
 			List<Spea2IndividualSet> lcandidates = new ArrayList<Spea2IndividualSet>(orderedLists.keySet());
@@ -406,6 +382,44 @@ public int compare(Spea2IndividualSet o1, Spea2IndividualSet o2) {
 		return lames;
 	}
 
+	/**
+	 * Helper function to preorder the candidates for getNearest() operation
+	 * 
+	 * @param candidates
+	 *            the candidate IndividualSets
+	 * @return the preordered IndividualSets
+	 */
+	protected Map<Spea2IndividualSet, List<Spea2IndividualSet>> getNearestPreOrder(
+			Collection<Spea2IndividualSet> candidates) {
+		Map<Spea2IndividualSet, List<Spea2IndividualSet>> orderedLists = new LinkedHashMap<Spea2IndividualSet, List<Spea2IndividualSet>>();
+
+		for (Spea2IndividualSet w0 : candidates) {
+			List<Spea2IndividualSet> list = new ArrayList<Spea2IndividualSet>();
+			for (Spea2IndividualSet w1 : candidates) {
+				if (w0 != w1) {
+					w1.setNextDistance(distance(w0, w1));
+					list.add(w1);
+				}
+			}
+			Collections.sort(list, new Comparator<Spea2IndividualSet>() {
+				@Override
+				public int compare(Spea2IndividualSet o1, Spea2IndividualSet o2) {
+					double v = o1.getNextDistance() - o2.getNextDistance();
+					if (v < 0) {
+						return -1;
+					} else if (v > 0) {
+						return 1;
+					} else {
+						return 0;
+					}
+				}
+
+			});
+			orderedLists.put(w0, list);
+		}
+		return orderedLists;
+	}
+
 	protected double getMinDistance(Spea2IndividualSet w0) {
 		double min = Double.MAX_VALUE;
 		for (Spea2IndividualSet w1 : individualSets) {
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MOPSO.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MOPSO.java
index 66f442b7..dc6b36f5 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MOPSO.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MOPSO.java
@@ -154,7 +154,7 @@ public void normalize(DoubleGenotype genotype) {
 	 */
 	@Override
 	public void initialize() {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleNonUniform.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleNonUniform.java
index 48754df8..1895dcfd 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleNonUniform.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleNonUniform.java
@@ -70,11 +70,12 @@ public MutateDoubleNonUniform(Rand random, NormalizeDouble normalize, Iteration
 	 */
 	@Override
 	protected double mutateElement(double x, double lb, double ub, double p) {
+		double element = x;
 		if (random.nextDouble() < p) {
 			double tau = random.nextBoolean() ? 1 : -1;
-			x += tau * delta(perturbation);
+			element += tau * delta(perturbation);
 		}
-		return x;
+		return element;
 	}
 
 	/**
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleUniform.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleUniform.java
index d1fe0250..af56a293 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleUniform.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/MutateDoubleUniform.java
@@ -68,11 +68,12 @@ public MutateDoubleUniform(Rand random, NormalizeDouble normalize,
 	 */
 	@Override
 	protected double mutateElement(double x, double lb, double ub, double p) {
+		double element = x;
 		if (random.nextDouble() < p) {
 			double v = (random.nextDouble() - 0.5) * perturbation;
-			x += v;
+			element += v;
 		}
-		return x;
+		return element;
 	}
 
 }
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/Particle.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/Particle.java
index 834e06a2..c37182ca 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/Particle.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/mopso/Particle.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.optimizers.mopso;
 
@@ -27,8 +26,6 @@
 import org.opt4j.core.Individual;
 import org.opt4j.core.Objectives;
 
-import com.google.inject.Inject;
-
 /**
  * The {@link Particle} extends the {@link Individual} by an id, a velocity
  * {@link Genotype}, a personal best {@link Genotype} and the corresponding best
@@ -47,14 +44,6 @@ public class Particle extends Individual {
 
 	protected Objectives objectivesBest = null;
 
-	/**
-	 * Constructs a {@link Particle}.
-	 */
-	@Inject
-	public Particle() {
-		super();
-	}
-
 	/**
 	 * Returns the velocity.
 	 * 
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/rs/RandomSearch.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/rs/RandomSearch.java
index 208e4403..e6b39504 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/rs/RandomSearch.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/rs/RandomSearch.java
@@ -65,6 +65,7 @@ public RandomSearch(Population population, IndividualFactory individualFactory,
 
 	@Override
 	public void initialize() {
+		// nothing to be done
 	}
 
 	@Override
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/CoolingSchedulesModule.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/CoolingSchedulesModule.java
index e1f6873e..33e971ff 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/CoolingSchedulesModule.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/CoolingSchedulesModule.java
@@ -53,14 +53,6 @@ public class CoolingSchedulesModule extends CoolingScheduleModule {
 	@Order(0)
 	protected Type type = Type.LINEAR;
 
-	/**
-	 * Constructs a {@link CoolingSchedulesModule}.
-	 * 
-	 */
-	public CoolingSchedulesModule() {
-		super();
-	}
-
 	/**
 	 * Type of {@link CoolingSchedule} to use.
 	 * 
diff --git a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/SimulatedAnnealing.java b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/SimulatedAnnealing.java
index 3f974631..ec4a26aa 100644
--- a/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/SimulatedAnnealing.java
+++ b/opt4j-optimizers/src/main/java/org/opt4j/optimizers/sa/SimulatedAnnealing.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.optimizers.sa;
 
@@ -69,6 +68,10 @@ public class SimulatedAnnealing implements IterativeOptimizer {
 
 	private final Iteration iteration;
 
+	private double fold;
+
+	private Individual old;
+
 	/**
 	 * Constructs a new {@link SimulatedAnnealing}.
 	 * 
@@ -90,9 +93,8 @@ public class SimulatedAnnealing implements IterativeOptimizer {
 	 *            the cooling schedule
 	 */
 	@Inject
-	public SimulatedAnnealing(Population population, Archive archive,
-			IndividualFactory individualFactory, IndividualCompleter completer,
-			Rand random, Neighbor<Genotype> neighbor, Copy<Genotype> copy,
+	public SimulatedAnnealing(Population population, Archive archive, IndividualFactory individualFactory,
+			IndividualCompleter completer, Rand random, Neighbor<Genotype> neighbor, Copy<Genotype> copy,
 			CoolingSchedule coolingSchedule, Iteration iteration) {
 		this.random = random;
 		this.neighbor = neighbor;
@@ -112,12 +114,9 @@ public SimulatedAnnealing(Population population, Archive archive,
 	 */
 	@Override
 	public void initialize() throws TerminationException {
-
+		// nothing to be done
 	}
 
-	private double fold;
-	private Individual old;
-
 	/*
 	 * (non-Javadoc)
 	 * 
@@ -128,7 +127,7 @@ public void next() throws TerminationException {
 
 		if (population.isEmpty()) {
 			// the first iteration
-			
+
 			old = individualFactory.create();
 
 			population.add(old);
@@ -137,7 +136,7 @@ public void next() throws TerminationException {
 			fold = f(old);
 		} else {
 			// all iterations > 1
-			
+
 			Genotype g = copy.copy(old.getGenotype());
 			neighbor.neighbor(g);
 
@@ -153,9 +152,7 @@ public void next() throws TerminationException {
 			if (fy <= fold) {
 				sw = true;
 			} else {
-				double a = (fold - fy)
-						/ coolingSchedule.getTemperature(iteration.value(),
-								iteration.max());
+				double a = (fold - fy) / coolingSchedule.getTemperature(iteration.value(), iteration.max());
 				double e = Math.exp(a);
 				if (random.nextDouble() < e) {
 					sw = true;
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/AbstractSATDecoder.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/AbstractSATDecoder.java
index a4a533ca..977f049c 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/AbstractSATDecoder.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/AbstractSATDecoder.java
@@ -19,7 +19,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
 
 package org.opt4j.satdecoding;
 
@@ -124,7 +123,7 @@ protected synchronized void init() {
 
 			} catch (Throwable e) {
 				System.err.println("Failed initialization of " + getClass().getName() + " with " + e);
-				throw new RuntimeException(e);
+				throw new IllegalArgumentException(e);
 			} finally {
 				isInit = true;
 			}
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Constraint.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Constraint.java
index e11bedf2..167e36c7 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Constraint.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Constraint.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.satdecoding;
 
 import java.util.ArrayList;
@@ -51,6 +50,8 @@ public class Constraint extends ArrayList<Term> {
 	protected Operator operator = Operator.GE;
 	protected int rhs = 1;
 
+	private static final long serialVersionUID = 1L;
+
 	/**
 	 * The {@link Operator}s correspond to the Boolean operators &lt;=,=,&gt;=.
 	 */
@@ -183,7 +184,7 @@ public Integer next() {
 
 					@Override
 					public void remove() {
-						throw new RuntimeException("Operation not supported");
+						throw new UnsupportedOperationException("Do not remove constraint coefficients.");
 					}
 				};
 			}
@@ -215,7 +216,7 @@ public Literal next() {
 
 					@Override
 					public void remove() {
-						throw new RuntimeException("Operation not supported");
+						throw new UnsupportedOperationException("Do not remove constraint literals.");
 					}
 				};
 			}
@@ -429,6 +430,4 @@ public boolean equals(Object obj) {
 		return (super.equals(other) && operator == other.operator && rhs == other.rhs);
 	}
 
-	private static final long serialVersionUID = 1L;
-
 }
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Model.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Model.java
index 6f5ad8c8..366a91fe 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Model.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Model.java
@@ -40,13 +40,6 @@ public class Model {
 
 	protected final Map<Object, Boolean> map = new HashMap<Object, Boolean>();
 
-	/**
-	 * Constructs a {@link Model}.
-	 */
-	public Model() {
-		super();
-	}
-
 	/**
 	 * Returns the value of the variable, or null if this variable is not
 	 * defined.
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Order.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Order.java
index a5d85957..ab3d1921 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Order.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Order.java
@@ -40,13 +40,6 @@ public abstract class Order {
 
 	protected double varDecay = 1;
 
-	/**
-	 * Constructs an {@link Order}.
-	 */
-	public Order() {
-		super();
-	}
-
 	/**
 	 * Returns the scaling factor for the offset value.
 	 * 
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Term.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Term.java
index 8500ff92..a433b7db 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Term.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/Term.java
@@ -46,7 +46,7 @@ public Term(int coeff, Literal lit) {
 		this.coeff = coeff;
 		this.lit = lit;
 		if (lit == null) {
-			throw new NullPointerException();
+			throw new IllegalArgumentException("Literal must not be null.");
 		}
 	}
 
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/VarOrder.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/VarOrder.java
index 29fe7b78..a46871a0 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/VarOrder.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/VarOrder.java
@@ -41,13 +41,6 @@ public class VarOrder extends Order {
 
 	protected final Map<Object, Boolean> phase = new HashMap<Object, Boolean>();
 
-	/**
-	 * Constructs a {@link VarOrder}.
-	 */
-	public VarOrder() {
-		super();
-	}
-
 	/**
 	 * Sets the activity of the specified variable.
 	 * 
diff --git a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/sat4j/VariableOrder.java b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/sat4j/VariableOrder.java
index f11d4365..979457cd 100644
--- a/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/sat4j/VariableOrder.java
+++ b/opt4j-satdecoding/src/main/java/org/opt4j/satdecoding/sat4j/VariableOrder.java
@@ -95,7 +95,7 @@ public void setLits(ILits lits) {
 	 */
 	@Override
 	public void init() {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-tutorial/src/main/java/org/opt4j/tutorial/helloworld/HelloWorldCreator.java b/opt4j-tutorial/src/main/java/org/opt4j/tutorial/helloworld/HelloWorldCreator.java
index 887f694f..b434e248 100644
--- a/opt4j-tutorial/src/main/java/org/opt4j/tutorial/helloworld/HelloWorldCreator.java
+++ b/opt4j-tutorial/src/main/java/org/opt4j/tutorial/helloworld/HelloWorldCreator.java
@@ -7,9 +7,9 @@
 
 public class HelloWorldCreator implements Creator<SelectGenotype<Character>> {
 
-	Character[] ALPHABET = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
+	protected Character[] ALPHABET = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
 			'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', ' ' };
-	Random random = new Random();
+	protected Random random = new Random();
 
 	public SelectGenotype<Character> create() {
 		SelectGenotype<Character> genotype = new SelectGenotype<Character>(ALPHABET);
diff --git a/opt4j-tutorial/src/main/java/org/opt4j/tutorial/minones/MinOnesEvaluator.java b/opt4j-tutorial/src/main/java/org/opt4j/tutorial/minones/MinOnesEvaluator.java
index 5cf962a9..9b7c5ba1 100644
--- a/opt4j-tutorial/src/main/java/org/opt4j/tutorial/minones/MinOnesEvaluator.java
+++ b/opt4j-tutorial/src/main/java/org/opt4j/tutorial/minones/MinOnesEvaluator.java
@@ -7,7 +7,7 @@
 
 public class MinOnesEvaluator implements Evaluator<MinOnesResult> {
 
-	Objective ones = new Objective("ones", Sign.MIN);
+	protected Objective ones = new Objective("ones", Sign.MIN);
 
 	@Override
 	public Objectives evaluate(MinOnesResult minOnesResult) {
diff --git a/opt4j-tutorial/src/main/java/org/opt4j/tutorial/salesman/SalesmanWidgetService.java b/opt4j-tutorial/src/main/java/org/opt4j/tutorial/salesman/SalesmanWidgetService.java
index 1472001a..143ff192 100644
--- a/opt4j-tutorial/src/main/java/org/opt4j/tutorial/salesman/SalesmanWidgetService.java
+++ b/opt4j-tutorial/src/main/java/org/opt4j/tutorial/salesman/SalesmanWidgetService.java
@@ -29,6 +29,8 @@
 // of a single route in the viewer.
 public class SalesmanWidgetService implements IndividualMouseListener {
 
+	protected final Viewport viewport;
+	
 	// Panel that paints a single SalesmanRoute (which is the phenotype of an
 	// Individual)
 	public static class MyPanel extends JPanel {
@@ -74,7 +76,7 @@ protected void paintComponent(Graphics g) {
 	@WidgetParameters(title = "Route", resizable = false, maximizable = false)
 	protected static class SalesmanWidget implements Widget {
 
-		final Individual individual;
+		protected final Individual individual;
 
 		public SalesmanWidget(Individual individual) {
 			super();
@@ -89,12 +91,11 @@ public JPanel getPanel() {
 
 		@Override
 		public void init(Viewport viewport) {
+			// nothing to be done
 		}
 
 	}
 
-	protected final Viewport viewport;
-
 	// The route is shown by a double click of a individual in the archive
 	// monitor panel. Thus we need the ArchiveMonitorPanel and the main
 	// GUIFrame.
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java
index a40d55d8..67d102e2 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.viewer;
 
 import java.awt.BorderLayout;
@@ -259,18 +258,22 @@ public void stateChanged(ChangeEvent e) {
 
 			@Override
 			public void columnAdded(TableColumnModelEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
 			public void columnMarginChanged(ChangeEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
 			public void columnMoved(TableColumnModelEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
 			public void columnRemoved(TableColumnModelEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
@@ -342,7 +345,7 @@ protected void sortIndividiualMouseListeners() {
 	 */
 	@Override
 	public synchronized void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	protected boolean updateOrder() {
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java
index aefe96fd..1054cfcf 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.viewer;
 
 import java.awt.geom.Point2D;
@@ -79,7 +79,7 @@ protected static class PlotDataObjective {
 		protected final List<Point2D.Double> meanValues = new CopyOnWriteArrayList<Point2D.Double>();
 		protected final int MAXVALUES = 2000;
 
-		final Set<Double> currentIteration = new HashSet<Double>();
+		protected final Set<Double> currentIteration = new HashSet<Double>();
 
 		PlotDataObjective(Objective objective) {
 			this.objective = objective;
@@ -98,7 +98,7 @@ public void update(Objectives objectives) {
 			}
 		}
 
-		protected synchronized void simplify(List<java.awt.geom.Point2D.Double> values) {
+		protected synchronized void simplify(List<Point2D.Double> values) {
 			if (values.size() > MAXVALUES) {
 				List<Point2D.Double> copy = new ArrayList<Point2D.Double>(values);
 
@@ -167,17 +167,15 @@ public void complete(int iteration) {
 			}
 		}
 
-		private void addValue(double min, List<java.awt.geom.Point2D.Double> points, int iteration) {
-			if (!Double.isInfinite(min)) {
-				if (points.isEmpty() || points.get(points.size() - 1).getY() != min) {
-					if (!points.isEmpty()) {
-						Point2D.Double steppoint = new Point2D.Double(iteration, points.get(points.size() - 1).getY());
-						points.add(steppoint);
-					}
-
-					Point2D.Double point = new Point2D.Double(iteration, min);
-					points.add(point);
+		private void addValue(double min, List<Point2D.Double> points, int iteration) {
+			if (!Double.isInfinite(min) && (points.isEmpty() || points.get(points.size() - 1).getY() != min)) {
+				if (!points.isEmpty()) {
+					Point2D.Double steppoint = new Point2D.Double(iteration, points.get(points.size() - 1).getY());
+					points.add(steppoint);
 				}
+
+				Point2D.Double point = new Point2D.Double(iteration, min);
+				points.add(point);
 			}
 		}
 	}
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java
index 11bddec3..d2f3234a 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java
@@ -211,7 +211,7 @@ public JPanel getPanel() {
 	 */
 	@Override
 	public void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java
index a492a43a..98bb9953 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java
@@ -217,7 +217,7 @@ public void registerAtObjectivesMonitor(ObjectivesMonitor objectivesMonitor) {
 	 */
 	@Override
 	public void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java
index dcb015eb..296e35ef 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java
@@ -252,7 +252,7 @@ protected final JTable getTable() {
 	 */
 	@Override
 	public synchronized void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java
index 5e5ac1d6..4c801caa 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java
@@ -168,6 +168,7 @@ public void iterationComplete(int iteration) {
 	 */
 	@Override
 	public void optimizationStarted(Optimizer optimizer) {
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java
index 68012736..12c409bc 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java
@@ -168,6 +168,7 @@ public void windowClosing(WindowEvent e) {
 					break;
 				default:
 					control.doStop();
+					break;
 				}
 				frame.dispose();
 			}
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java
index b649824e..43b29527 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java
@@ -56,14 +56,6 @@ public class Viewport {
 
 	protected final Map<Widget, JInternalFrame> widgets = new HashMap<Widget, JInternalFrame>();
 
-	/**
-	 * Constructs a {@link Viewport} for {@link Widget}s.
-	 * 
-	 */
-	public Viewport() {
-
-	}
-
 	/**
 	 * Initialization. This method has to be called once after construction.
 	 */