diff --git a/lib/porp.rb b/lib/porp.rb
index b9a3827..a2a7645 100755
--- a/lib/porp.rb
+++ b/lib/porp.rb
@@ -58,4 +58,5 @@ def self.purge_current_namespace!
 
 require 'porp/orpmodel'
 require 'porp/stockentity'
+require 'porp/stockholding'
 require 'porp/saleentity'
diff --git a/lib/porp/orpmodel.rb b/lib/porp/orpmodel.rb
index 609edda..748ee81 100755
--- a/lib/porp/orpmodel.rb
+++ b/lib/porp/orpmodel.rb
@@ -19,13 +19,17 @@ def initialize(id)
     def ==(other)
       @id.to_s == other.id.to_s
     end
+    
+    # Formats the class name of the object for use in the redis keyspace
+    def self.rklass
+      self.name.downcase.match(/(\w+)$/)[0]
+    end
   
     # Fetches the next available id for a new record. This method sets a
     # record key with this id so effectively creates the record  
     def self.new_id
-      klass = self.name.downcase
-      id = redis.incr("#{Porp.ns}:#{klass}:uid")
-      redis.set("#{Porp.ns}:#{klass}:id:#{id.to_s}:created", 1)
+      id = redis.incr("#{Porp.ns}:#{rklass}:uid")
+      redis.set("#{Porp.ns}:#{rklass}:id:#{id.to_s}:created", 1)
       id
     end
 
@@ -36,13 +40,11 @@ def self.find_by_id(id)
 
     # Checks whether a record exists
     def self.exists?(id)
-      klass = self.name.downcase
-      redis.key?("#{Porp.ns}:#{klass}:id:#{id.to_s}:created")
+      redis.key?("#{Porp.ns}:#{rklass}:id:#{id.to_s}:created")
     end
 
     # Creates accessor methods for attributes stored as simple values in the db
     def self.property(*names)
-      klass = self.name.downcase
       names.each do |name|
         self.class_eval <<-EOCE
           def #{name}
@@ -50,11 +52,11 @@ def #{name}
           end
       
           def _#{name}
-            redis.get("#{Porp.ns}:#{klass}:id:" + id.to_s + ":#{name}")
+            redis.get("#{Porp.ns}:#{rklass}:id:" + id.to_s + ":#{name}")
           end
 
           def #{name}=(val)
-            redis.set("#{Porp.ns}:#{klass}:id:" + id.to_s + ":#{name}", val)
+            redis.set("#{Porp.ns}:#{rklass}:id:" + id.to_s + ":#{name}", val)
           end
         EOCE
       end
diff --git a/lib/porp/stockentity.rb b/lib/porp/stockentity.rb
index 7bc7e8d..2c0f0c5 100755
--- a/lib/porp/stockentity.rb
+++ b/lib/porp/stockentity.rb
@@ -43,21 +43,15 @@ def sale_entities
     end
     
     # Associates the StockEntity with a StockHolding
-    def add_stock_holding(stkh_id)
-      if StockHolding.exists?(stkh_id)
-        stkh = StockHolding.new(stkh_id)
-        # Don't associate with other StockEntities' StockHoldings
-        raise if stkh.stock_entity != id
-        redis.sadd("#{Porp.ns}:stockholding:id:#{id}:stockholdings", stkh_id)
-      else
-        false
-      end
+    def add_new_stock_holding(quantity, cost)
+      stkh = Porp::StockHolding.create(self, quantity, cost)
+      redis.sadd("#{Porp.ns}:stockholding:id:#{id}:stockholdings", stkh.id)
     end
     
     # Archive an end-of-life StockHolding
-    def archive_stock_holding(stkh_id)
+    def archive_stock_holding(stkh)
       redis.smove("#{Porp.ns}:stockholding:id:#{id}:stockholdings",
-                  "#{Porp.ns}:stockholding:id:#{id}:archivestockholdings", stkh_id)
+                  "#{Porp.ns}:stockholding:id:#{id}:archivestockholdings", stkh.id)
     end
   end
 end
diff --git a/lib/porp/stockholding.rb b/lib/porp/stockholding.rb
index 0dd16e3..26ea8bd 100755
--- a/lib/porp/stockholding.rb
+++ b/lib/porp/stockholding.rb
@@ -22,19 +22,27 @@ class Porp
 in similar fashion.
 =end
   class StockHolding < OrpModel
-    property :stock_entity
+    property :stock_entity_id
+    property :quantity
+    property :unit_cost
   
-    # Creates a new StockHolding record linked to StockEntity with id stke_id
-    def self.create(stke_id)
-      if StockEntity.exists?(stke_id)
-        new_stock_holding = self.new(self.new_id)
-        new_stock_holding.stock_entity = stke_id
-        stock_entity = StockEntity.new(stke_id)
-        stock_entity.add_stock_holding(new_stock_holding.id)
-        new_stock_holding
-      else
-        false
-      end
+    # Creates a new StockHolding record linked to StockEntity stke
+    def self.create(stke, quantity, unit_cost)
+      new_stkh = self.new(self.new_id)
+      new_stkh.stock_entity_id = stke.id
+      new_stkh.quantity = quantity
+      new_stkh.unit_cost = unit_cost
+      new_stkh
+    end
+    
+    def stock_entity
+      Porp::StockEntity.new(stock_entity_id)
+    end
+    
+    # Returns whether the StockHolding is end of life. True when quantity is
+    # zero (and StockMovements > 0?)
+    def eol?
+      quantity == 0
     end
   end
 end