diff --git a/docs/development.rst b/docs/development.rst
index 478254aa..2bbf9eeb 100644
--- a/docs/development.rst
+++ b/docs/development.rst
@@ -95,6 +95,8 @@ Implement an Action
    - Make use of ``kwargs['logger']``, available in ``setup()``
    - If you want to draw markers for RViz, use ``kwargs['marker_handler']``, available in ``setup()`` (with ROS backend)
 - Use arguments from ``__init__()`` for a longer running initialization in ``setup()`` and the arguments from ``execute()`` to set values just before executing the action.
+  - ``__init__()`` does not need to contain all osc2-defined arguments. This can be convenient as variable argument resolving might not be available during ``__init__()``.
+  - ``execute()`` contains all osc2-arguments.
 - ``setup()`` provides several arguments that might be useful:
   - ``input_dir``: Directory containing the scenario file
   - ``output_dir``: If given on command-line, contains the directory to save output to
diff --git a/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_floorplan.py b/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_floorplan.py
index 5cb9df93..863e7f2c 100644
--- a/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_floorplan.py
+++ b/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_floorplan.py
@@ -18,7 +18,7 @@
 from enum import Enum
 
 import py_trees
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 import docker
 import tempfile
@@ -46,20 +46,20 @@ def setup(self, **kwargs):
         # self.output_dir = tempfile.mkdtemp() # for testing: does not remove directory afterwards
 
         if "input_dir" not in kwargs:
-            raise ValueError("input_dir not defined.")
+            raise ActionError("input_dir not defined.", action=self)
         input_dir = kwargs["input_dir"]
         # check docker image
         self.client = docker.from_env()
         image_name = 'floorplan:latest'
         filterred_images = self.client.images.list(filters={'reference': image_name})
         if len(filterred_images) == 0:
-            raise ValueError(f"Required docker image '{image_name}' does not exist.")
+            raise ActionError(f"Required docker image '{image_name}' does not exist.", action=self)
 
         # check files
         if not os.path.isabs(self.file_path):
             self.file_path = os.path.join(input_dir, self.file_path)
         if not os.path.isfile(self.file_path):
-            raise ValueError(f"Floorplan file {self.file_path} not found.")
+            raise ActionError(f"Floorplan file {self.file_path} not found.", action=self)
         self.floorplan_name = os.path.splitext(os.path.basename(self.file_path))[0]
 
     def update(self) -> py_trees.common.Status:
diff --git a/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_gazebo_world.py b/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_gazebo_world.py
index c0be2116..c8dd7d24 100644
--- a/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_gazebo_world.py
+++ b/libs/scenario_execution_floorplan_dsl/scenario_execution_floorplan_dsl/actions/generate_gazebo_world.py
@@ -17,7 +17,7 @@
 import os
 import py_trees
 from scenario_execution_gazebo.actions.utils import SpawnUtils
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 from shutil import which
 import tempfile
 
@@ -31,15 +31,15 @@ def __init__(self, associated_actor, sdf_template: str, arguments: list):
 
     def setup(self, **kwargs):
         if which("xacro") is None:
-            raise ValueError("'xacro' not found.")
+            raise ActionError("'xacro' not found.", action=self)
         if "input_dir" not in kwargs:
-            raise ValueError("input_dir not defined.")
+            raise ActionError("input_dir not defined.", action=self)
         input_dir = kwargs["input_dir"]
 
         if not os.path.isabs(self.sdf_template):
             self.sdf_template = os.path.join(input_dir, self.sdf_template)
         if not os.path.isfile(self.sdf_template):
-            raise ValueError(f"SDF Template {self.sdf_template} not found.")
+            raise ActionError(f"SDF Template {self.sdf_template} not found.", action=self)
         self.tmp_file = tempfile.NamedTemporaryFile(suffix=".sdf")  # for testing, do not delete temp file: delete=False
 
     def execute(self, associated_actor, sdf_template: str, arguments: list):
diff --git a/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_relative_spawn_actor.py b/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_relative_spawn_actor.py
index d3da21d4..22ab2e8d 100644
--- a/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_relative_spawn_actor.py
+++ b/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_relative_spawn_actor.py
@@ -21,6 +21,7 @@
 from tf2_ros.transform_listener import TransformListener
 from tf2_geometry_msgs import PoseStamped
 from .gazebo_spawn_actor import GazeboSpawnActor
+from scenario_execution.actions.base_action import ActionError
 
 
 class GazeboRelativeSpawnActor(GazeboSpawnActor):
@@ -97,4 +98,4 @@ def calculate_new_pose(self):
                 f' w: {new_pose.pose.orientation.w} x: {new_pose.pose.orientation.x} y: {new_pose.pose.orientation.y} z: {new_pose.pose.orientation.z}' \
                 ' } }'
         except TransformException as e:
-            raise ValueError(f"No transform available ({self.parent_frame_id}->{self.frame_id})") from e
+            raise ActionError(f"No transform available ({self.parent_frame_id}->{self.frame_id})", action=self) from e
diff --git a/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_spawn_actor.py b/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_spawn_actor.py
index 2d8fe1dc..7ea6b56d 100644
--- a/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_spawn_actor.py
+++ b/libs/scenario_execution_gazebo/scenario_execution_gazebo/actions/gazebo_spawn_actor.py
@@ -23,6 +23,7 @@
 from rclpy.qos import QoSProfile, QoSDurabilityPolicy, QoSHistoryPolicy, QoSReliabilityPolicy
 from rclpy.node import Node
 import py_trees
+from scenario_execution.actions.base_action import ActionError
 from scenario_execution.actions.run_process import RunProcess
 from .utils import SpawnUtils
 
@@ -68,7 +69,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         self.utils = SpawnUtils(logger=self.logger)
 
@@ -88,12 +89,12 @@ def setup(self, **kwargs):
                 self.entity_model, self.entity_name, self.xacro_arguments)
 
             if not self.sdf:
-                raise ValueError(f'Invalid model specified ({self.entity_model})')
+                raise ActionError(f'Invalid model specified ({self.entity_model})', action=self)
             self.current_state = SpawnActionState.MODEL_AVAILABLE
 
     def execute(self, associated_actor, spawn_pose: list, world_name: str, xacro_arguments: list, model: str):  # pylint: disable=arguments-differ
         if self.entity_model != model or set(self.xacro_arguments) != set(xacro_arguments):
-            raise ValueError("Runtime change of model not supported.")
+            raise ActionError("Runtime change of model not supported.", action=self)
         self.spawn_pose = spawn_pose
         self.world_name = world_name
 
@@ -175,7 +176,7 @@ def get_spawn_pose(self):
                 f' w: {quaternion[0]} x: {quaternion[1]} y: {quaternion[2]} z: {quaternion[3]}' \
                 ' } }'
         except KeyError as e:
-            raise ValueError("Could not get values") from e
+            raise ActionError("Could not get values", action=self) from e
         return pose
 
     def set_command(self, command):
diff --git a/libs/scenario_execution_nav2/scenario_execution_nav2/actions/init_nav2.py b/libs/scenario_execution_nav2/scenario_execution_nav2/actions/init_nav2.py
index 7c27c851..1bbeac9d 100644
--- a/libs/scenario_execution_nav2/scenario_execution_nav2/actions/init_nav2.py
+++ b/libs/scenario_execution_nav2/scenario_execution_nav2/actions/init_nav2.py
@@ -31,7 +31,7 @@
 
 from .nav2_common import NamespaceAwareBasicNavigator
 from scenario_execution_ros.actions.common import get_pose_stamped, NamespacedTransformListener
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class InitNav2State(Enum):
@@ -91,7 +91,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         self.tf_buffer = Buffer()
         self.tf_listener = NamespacedTransformListener(
diff --git a/libs/scenario_execution_pybullet/scenario_execution_pybullet/actions/sim_run.py b/libs/scenario_execution_pybullet/scenario_execution_pybullet/actions/sim_run.py
index c4ba4688..358a3e62 100644
--- a/libs/scenario_execution_pybullet/scenario_execution_pybullet/actions/sim_run.py
+++ b/libs/scenario_execution_pybullet/scenario_execution_pybullet/actions/sim_run.py
@@ -15,7 +15,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import py_trees
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 import pybullet as p
 import math
 
@@ -30,10 +30,10 @@ def setup(self, **kwargs):
         try:
             tick_period: float = kwargs['tick_period']
         except KeyError as e:
-            raise KeyError("didn't find 'tick_period' in setup's kwargs") from e
+            raise ActionError("didn't find 'tick_period' in setup's kwargs", action=self) from e
         if not math.isclose(240 % tick_period, 0., abs_tol=1e-4):
-            raise ValueError(
-                f"Scenario Execution Tick Period of {tick_period} is not compatible with PyBullet stepping. Please set step-duration to be a multiple of 1/240s")
+            raise ActionError(
+                f"Scenario Execution Tick Period of {tick_period} is not compatible with PyBullet stepping. Please set step-duration to be a multiple of 1/240s", action=self)
         self.sim_steps_per_tick = round(240 * tick_period)
         self.logger.info(f"Forward simulation by {self.sim_steps_per_tick} step per scenario tick.")
 
diff --git a/libs/scenario_execution_x11/scenario_execution_x11/actions/capture_screen.py b/libs/scenario_execution_x11/scenario_execution_x11/actions/capture_screen.py
index 432c49aa..c28ab8eb 100644
--- a/libs/scenario_execution_x11/scenario_execution_x11/actions/capture_screen.py
+++ b/libs/scenario_execution_x11/scenario_execution_x11/actions/capture_screen.py
@@ -17,6 +17,7 @@
 from enum import Enum
 import py_trees
 import os
+from scenario_execution.actions.base_action import ActionError
 from scenario_execution.actions.run_process import RunProcess
 
 
@@ -36,12 +37,12 @@ def __init__(self, output_filename: str, frame_rate: float):
 
     def setup(self, **kwargs):
         if "DISPLAY" not in os.environ:
-            raise ValueError("capture_screen() requires environment variable 'DISPLAY' to be set.")
+            raise ActionError("capture_screen() requires environment variable 'DISPLAY' to be set.", action=self)
 
         if kwargs['output_dir']:
             if not os.path.exists(kwargs['output_dir']):
-                raise ValueError(
-                    f"Specified destination dir '{kwargs['output_dir']}' does not exist")
+                raise ActionError(
+                    f"Specified destination dir '{kwargs['output_dir']}' does not exist", action=self)
             self.output_dir = kwargs['output_dir']
 
     def execute(self, output_filename: str, frame_rate: float):  # pylint: disable=arguments-differ
diff --git a/scenario_execution/scenario_execution/actions/base_action.py b/scenario_execution/scenario_execution/actions/base_action.py
index c4e254fb..3e5d8893 100644
--- a/scenario_execution/scenario_execution/actions/base_action.py
+++ b/scenario_execution/scenario_execution/actions/base_action.py
@@ -16,6 +16,7 @@
 
 import py_trees
 from scenario_execution.model.types import ParameterDeclaration, ScenarioDeclaration
+from scenario_execution.model.error import OSC2Error
 
 
 class BaseAction(py_trees.behaviour.Behaviour):
@@ -78,7 +79,7 @@ def get_blackboard_namespace(node: ParameterDeclaration):
 
     def register_access_to_associated_actor_variable(self, variable_name):
         if not self._model.actor:
-            raise ValueError("Model does not have 'actor'.")
+            raise ActionError("Model does not have 'actor'.", action=self)
         blackboard = self.get_blackboard_client()
         model_blackboard_name = self._model.actor.get_fully_qualified_var_name(include_scenario=False)
         model_blackboard_name += "/" + variable_name
@@ -94,3 +95,11 @@ def get_associated_actor_variable(self, variable_name):
         model_blackboard_name = self.register_access_to_associated_actor_variable(variable_name)
         self.logger.debug(f"Get variable '{model_blackboard_name}'")
         return getattr(self.get_blackboard_client(), model_blackboard_name)
+
+
+class ActionError(OSC2Error):
+
+    def __init__(self, msg: str, action: BaseAction, *args) -> None:
+        if action is not None:
+            ctx = action._model.get_ctx()
+        super().__init__(msg, ctx, *args)
diff --git a/scenario_execution/scenario_execution/actions/log.py b/scenario_execution/scenario_execution/actions/log.py
index b57d6d1a..4cc77f66 100644
--- a/scenario_execution/scenario_execution/actions/log.py
+++ b/scenario_execution/scenario_execution/actions/log.py
@@ -16,7 +16,7 @@
 
 import py_trees
 from py_trees.common import Status
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class Log(BaseAction):
@@ -38,7 +38,7 @@ def update(self) -> py_trees.common.Status:
         if not self.published:
             self.published = True
             if not self.msg:
-                raise ValueError("log(): Empty message.")
+                raise ActionError("log(): Empty message.", action=self)
             self.logger.info(f"{self.msg}")
 
         return Status.SUCCESS
diff --git a/scenario_execution/scenario_execution/model/error.py b/scenario_execution/scenario_execution/model/error.py
index 6c64d4bb..8d1c076f 100644
--- a/scenario_execution/scenario_execution/model/error.py
+++ b/scenario_execution/scenario_execution/model/error.py
@@ -18,24 +18,36 @@
 from antlr4 import ParserRuleContext
 
 
-class OSC2ParsingError(Exception):
-    """
-    Error class for OSC2 parser
-    """
+class OSC2Error(Exception):
 
     def __init__(self, msg: str, context, *args) -> None:
         super().__init__(*args)
         self.msg = msg
         if isinstance(context, ParserRuleContext):
-            self.line = context.start.line
-            self.column = context.start.column
-            self.context = context.getText()
-            self.filename = ""
+            self.osc_ctx = (context.start.line, context.start.column, context.getText(), "")
         else:
-            self.line = context[0]
-            self.column = context[1]
-            self.context = context[2]
-            self.filename = context[3]
+            self.osc_ctx = context
 
     def __str__(self) -> str:
-        return self.msg
+        error_str = ""
+        if self.osc_ctx is not None:
+            if len(self.osc_ctx) == 4:
+                context = self.osc_ctx[2].replace('\n', '')
+                error_str = f"(line: {self.osc_ctx[0]}, column: {self.osc_ctx[1]} in '{self.osc_ctx[3]}') -> {context}: "
+            else:
+                error_str = f"<invalid context: {self.osc_ctx}>: "
+        error_str += self.msg
+        return error_str
+
+
+class OSC2ParsingError(OSC2Error):
+    """
+    Error class for OSC2 parser
+    """
+
+    def __init__(self, msg: str, context, *args) -> None:
+        if isinstance(context, ParserRuleContext):
+            ctx = (context.start.line, context.start.column, context.getText(), "")
+        else:
+            ctx = context
+        super().__init__(msg, ctx, *args)
diff --git a/scenario_execution/scenario_execution/model/model_blackboard.py b/scenario_execution/scenario_execution/model/model_blackboard.py
index d2456522..de59e7d3 100644
--- a/scenario_execution/scenario_execution/model/model_blackboard.py
+++ b/scenario_execution/scenario_execution/model/model_blackboard.py
@@ -26,8 +26,7 @@ def create_py_tree_blackboard(model, tree, logger, log_tree):
     try:
         model_blackboard.build(model, tree, log_tree)
     except OSC2ParsingError as e:
-        raise ValueError(
-            f'Error while creating py-tree:\nTraceback <line: {e.line}, column: {e.column}> in "{e.filename}":\n  -> {e.context}\n{e.__class__.__name__}: {e.msg}') from e
+        raise ValueError(f'Error while creating py-tree: {e}') from e
 
 
 class ModelToBlackboard(object):
diff --git a/scenario_execution/scenario_execution/model/model_resolver.py b/scenario_execution/scenario_execution/model/model_resolver.py
index 81118477..87ddfa81 100644
--- a/scenario_execution/scenario_execution/model/model_resolver.py
+++ b/scenario_execution/scenario_execution/model/model_resolver.py
@@ -29,8 +29,7 @@ def resolve_internal_model(model, tree, logger, log_tree):
     try:
         osc2scenario_resolver.visit(model)
     except OSC2ParsingError as e:
-        raise ValueError(
-            f'Error while creating tree:\nTraceback <line: {e.line}, column: {e.column}> in "{e.filename}":\n  -> {e.context}\n{e.__class__.__name__}: {e.msg}') from e
+        raise ValueError(f'Error while creating tree: {e}') from e
 
     if log_tree:
         logger.info("----Internal model (resolved)-----")
diff --git a/scenario_execution/scenario_execution/model/model_to_py_tree.py b/scenario_execution/scenario_execution/model/model_to_py_tree.py
index f5a0074a..cecda3b7 100644
--- a/scenario_execution/scenario_execution/model/model_to_py_tree.py
+++ b/scenario_execution/scenario_execution/model/model_to_py_tree.py
@@ -31,8 +31,7 @@ def create_py_tree(model, tree, logger, log_tree):
     try:
         final_tree = model_to_py_tree.build(model, tree, log_tree)
     except OSC2ParsingError as e:
-        raise ValueError(
-            f'Error while creating py-tree:\nTraceback <line: {e.line}, column: {e.column}> in "{e.filename}":\n  -> {e.context}\n{e.__class__.__name__}: {e.msg}') from e
+        raise ValueError(f'Error while creating py-tree: {e}') from e
     return final_tree
 
 
@@ -102,15 +101,15 @@ def update(self):
         return Status.SUCCESS
 
 
-class ExpressionBehavior(py_trees.behaviour.Behaviour):
-
-    def __init__(self, name: "ExpressionBehavior", expression: Expression):
-        super().__init__(name)
+class ExpressionBehavior(BaseAction):  # py_trees.behaviour.Behaviour):
 
+    def __init__(self, name: "ExpressionBehavior", expression: Expression, model, logger):
+        super().__init__()
+        self._set_base_properities(name, model, logger)
         self.expression = expression
 
     def update(self):
-        if self.expression.eval():
+        if self.expression.eval(self.get_blackboard_client()):
             return Status.SUCCESS
         else:
             return Status.RUNNING
@@ -215,7 +214,7 @@ def compare_method_arguments(self, method, expected_args, behavior_name, node):
                 if error_string:
                     error_string += ", "
                 error_string += "unknown: " + ", ".join(unknown_args)
-            return method_args, error_string
+            return method_args, error_string, missing_args
 
         def create_decorator(self, node: ModifierDeclaration, resolved_values):
             available_modifiers = ["repeat", "inverter", "timeout", "retry", "failure_is_running", "failure_is_success",
@@ -311,18 +310,19 @@ def visit_behavior_invocation(self, node: BehaviorInvocation):
                     # if __init__() is defined, check parameters. Allowed:
                     # - __init__(self)
                     # - __init__(self, resolve_variable_reference_arguments_in_execute)
-                    # - __init__(self, <all-osc-defined-args>)
-                    init_args, error_string = self.compare_method_arguments(init_method, expected_args, behavior_name, node)
+                    # - __init__(self, <some-or-all-osc-defined-args>)
+                    init_args, error_string, args_not_in_init = self.compare_method_arguments(
+                        init_method, expected_args, behavior_name, node)
                     if init_args != ["self"] and \
                             init_args != ["self", "resolve_variable_reference_arguments_in_execute"] and \
-                            set(init_args) != set(expected_args):
+                            not all(x in expected_args for x in init_args):
                         raise OSC2ParsingError(
-                            msg=f'Plugin {behavior_name}: __init__() either only has "self" argument or all arguments defined in osc. {error_string}\n'
+                            msg=f'Plugin {behavior_name}: __init__() either only has "self" argument and osc-defined arguments. {error_string}\n'
                                 f'expected definition with all arguments: {expected_args}', context=node.get_ctx()
                         )
                 execute_method = getattr(behavior_cls, "execute", None)
                 if execute_method is not None:
-                    _, error_string = self.compare_method_arguments(execute_method, expected_args, behavior_name, node)
+                    _, error_string, _ = self.compare_method_arguments(execute_method, expected_args, behavior_name, node)
                     if error_string:
                         raise OSC2ParsingError(
                             msg=f'Plugin {behavior_name}: execute() arguments differ from osc-definition: {error_string}.', context=node.get_ctx()
@@ -336,12 +336,14 @@ def visit_behavior_invocation(self, node: BehaviorInvocation):
                     f"Instantiate action '{action_name}', plugin '{behavior_name}'. with:\nExpected execute() arguments: {expected_args}")
                 try:
                     if init_args is not None and init_args != ['self'] and init_args != ['self', 'resolve_variable_reference_arguments_in_execute']:
-                        final_args = node.get_resolved_value(self.blackboard)
+                        final_args = node.get_resolved_value(self.blackboard, skip_keys=args_not_in_init)
 
                         if node.actor:
                             final_args["associated_actor"] = node.actor.get_resolved_value(self.blackboard)
                             final_args["associated_actor"]["name"] = node.actor.name
 
+                        for k in args_not_in_init:
+                            del final_args[k]
                         instance = behavior_cls(**final_args)
                     else:
                         instance = behavior_cls()
@@ -363,7 +365,7 @@ def visit_event_condition(self, node: EventCondition):
             expression = ""
             for child in node.get_children():
                 if isinstance(child, (RelationExpression, LogicalExpression)):
-                    expression = ExpressionBehavior(name=node.get_ctx()[2], expression=self.visit(child))
+                    expression = ExpressionBehavior(name=node.get_ctx()[2], expression=self.visit(child), model=node, logger=self.logger)
                 elif isinstance(child, ElapsedExpression):
                     elapsed_condition = self.visit_elapsed_expression(child)
                     expression = py_trees.timers.Timer(name=f"wait {elapsed_condition}s", duration=float(elapsed_condition))
diff --git a/scenario_execution/scenario_execution/model/osc2_parser.py b/scenario_execution/scenario_execution/model/osc2_parser.py
index 94118ffb..1da88337 100644
--- a/scenario_execution/scenario_execution/model/osc2_parser.py
+++ b/scenario_execution/scenario_execution/model/osc2_parser.py
@@ -64,8 +64,7 @@ def load_internal_model(self, tree, file_name: str, log_model: bool = False, deb
             walker.walk(model_builder, tree)
             model = model_builder.get_model()
         except OSC2ParsingError as e:
-            raise ValueError(
-                f'Error creating internal model: Traceback <line: {e.line}, column: {e.column}> in "{e.filename}":\n  -> {e.context}\n{e.__class__.__name__}: {e.msg}') from e
+            raise ValueError(f'Error creating internal model: {e}') from e
         if log_model:
             self.logger.info("----Internal model-----")
             print_tree(model, self.logger)
diff --git a/scenario_execution/scenario_execution/model/types.py b/scenario_execution/scenario_execution/model/types.py
index 9903e826..9148ef76 100644
--- a/scenario_execution/scenario_execution/model/types.py
+++ b/scenario_execution/scenario_execution/model/types.py
@@ -394,7 +394,9 @@ def get_parameter_names(self):
                 names.append(child.name)
         return list(set(names))
 
-    def get_resolved_value(self, blackboard=None):
+    def get_resolved_value(self, blackboard=None, skip_keys=None):
+        if skip_keys is None:
+            skip_keys = []
         params = {}
 
         # set values defined in base type
@@ -406,6 +408,8 @@ def get_resolved_value(self, blackboard=None):
         param_keys = list(params.keys())
         for child in self.get_children():
             if isinstance(child, ParameterDeclaration):
+                if child.name in skip_keys:
+                    continue
                 # set from parameter
                 param_type, _ = child.get_type()
 
@@ -433,16 +437,19 @@ def get_resolved_value(self, blackboard=None):
                 if named:
                     raise OSC2ParsingError(
                         msg=f'Positional argument after named argument not allowed.', context=child.get_ctx())
-                params[param_keys[pos]] = child.get_resolved_value(blackboard)
+                if param_keys[pos] not in skip_keys:
+                    params[param_keys[pos]] = child.get_resolved_value(blackboard)
                 pos += 1
             elif isinstance(child, NamedArgument):
                 named = True
-                params[child.name] = child.get_resolved_value(blackboard)
+                if child.name not in skip_keys:
+                    params[child.name] = child.get_resolved_value(blackboard)
             elif isinstance(child, KeepConstraintDeclaration):
                 tmp = child.get_resolved_value(blackboard)
                 merge_nested_dicts(params, tmp, key_must_exist=False)
             elif isinstance(child, MethodDeclaration):
-                params[child.name] = child.get_resolved_value(blackboard)
+                if child.name not in skip_keys:
+                    params[child.name] = child.get_resolved_value(blackboard)
 
         return params
 
@@ -1836,7 +1843,7 @@ def get_type_string(self):
         return type_string
 
     def get_resolved_value(self, blackboard=None):
-        return visit_expression(self, blackboard).eval()
+        return visit_expression(self, blackboard).eval(blackboard)
 
 
 class UnaryExpression(ModelExpression):
@@ -1904,7 +1911,7 @@ def get_type_string(self):
         return "bool"
 
     def get_resolved_value(self, blackboard=None):
-        return visit_expression(self, blackboard).eval()
+        return visit_expression(self, blackboard).eval(blackboard)
 
 
 class RelationExpression(ModelExpression):
@@ -1931,7 +1938,7 @@ def get_type_string(self):
         return "bool"
 
     def get_resolved_value(self, blackboard=None):
-        return visit_expression(self, blackboard).eval()
+        return visit_expression(self, blackboard).eval(blackboard)
 
 
 class ListExpression(ModelExpression):
@@ -2272,20 +2279,22 @@ def __init__(self, left, right, operator) -> None:
         self.right = right
         self.operator = operator
 
-    def resolve(self, param):
+    def resolve(self, param, blackboard):
         if isinstance(param, Expression):
-            return param.eval()
+            return param.eval(blackboard)
         elif isinstance(param, VariableReference):
             return param.get_value()
+        elif isinstance(param, FunctionApplicationExpression):
+            return param.get_resolved_value(blackboard)
         else:
             return param
 
-    def eval(self):
-        left = self.resolve(self.left)
+    def eval(self, blackboard):
+        left = self.resolve(self.left, blackboard)
         if self.right is None:
             return self.operator(left)
         else:
-            right = self.resolve(self.right)
+            right = self.resolve(self.right, blackboard)
             return self.operator(left, right)
 
 
@@ -2339,6 +2348,8 @@ def visit_expression(node, blackboard):
                     args[idx] = var_def
                 else:
                     args[idx] = child.get_resolved_value(blackboard)
+            elif isinstance(child, FunctionApplicationExpression):
+                args[idx] = child
             else:
                 args[idx] = child.get_resolved_value(blackboard)
         idx += 1
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/assert_lifecycle_state.py b/scenario_execution_ros/scenario_execution_ros/actions/assert_lifecycle_state.py
index 7138b38a..6701e418 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/assert_lifecycle_state.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/assert_lifecycle_state.py
@@ -19,7 +19,7 @@
 from lifecycle_msgs.srv import GetState
 from lifecycle_msgs.msg import TransitionEvent
 from scenario_execution_ros.actions.conversions import get_qos_preset_profile
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 from enum import Enum
 from queue import Queue
 from collections import deque
@@ -56,7 +56,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         topic_transition_event_name = "/" + self.node_name + "/transition_event"
         self.subscription = self.node.create_subscription(
@@ -67,7 +67,7 @@ def setup(self, **kwargs):
 
     def execute(self, node_name: str, state_sequence: list, allow_initial_skip: bool, fail_on_unexpected: bool, keep_running: bool):
         if self.node_name != node_name or self.state_sequence != state_sequence:
-            raise ValueError("Runtime change of arguments 'name', 'state_sequence not supported.")
+            raise ActionError("Runtime change of arguments 'name', 'state_sequence not supported.", action=self)
 
         if all(isinstance(state, tuple) and len(state) == 2 for state in self.state_sequence):
             self.state_sequence = [state[0] for state in self.state_sequence]
@@ -75,7 +75,7 @@ def execute(self, node_name: str, state_sequence: list, allow_initial_skip: bool
             allowed_states = ['unconfigured', 'inactive', 'active', 'finalized']
             for value in self.state_sequence:
                 if value not in allowed_states:
-                    raise ValueError("The specified state_sequence is not valid")
+                    raise ActionError("The specified state_sequence is not valid", action=self)
         self.state_sequence = deque(self.state_sequence)
         self.allow_initial_skip = allow_initial_skip
         self.fail_on_unexpected = fail_on_unexpected
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/assert_tf_moving.py b/scenario_execution_ros/scenario_execution_ros/actions/assert_tf_moving.py
index 0e13c518..2b2164bc 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/assert_tf_moving.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/assert_tf_moving.py
@@ -20,7 +20,7 @@
 import time
 import tf2_ros
 from .common import NamespacedTransformListener
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 from tf2_ros import TransformException  # pylint: disable= no-name-in-module
 import math
 
@@ -51,7 +51,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         self.feedback_message = f"Waiting for transform {self.parent_frame_id} --> {self.frame_id}"  # pylint: disable= attribute-defined-outside-init
         self.tf_buffer = tf2_ros.Buffer()
@@ -67,7 +67,7 @@ def setup(self, **kwargs):
 
     def execute(self, frame_id: str, parent_frame_id: str, timeout: int, threshold_translation: float, threshold_rotation: float, wait_for_first_transform: bool, tf_topic_namespace: str, use_sim_time: bool):
         if self.tf_topic_namespace != tf_topic_namespace:
-            raise ValueError("Runtime change of argument 'tf_topic_namespace' not supported.")
+            raise ActionError("Runtime change of argument 'tf_topic_namespace' not supported.", action=self)
         self.frame_id = frame_id
         self.parent_frame_id = parent_frame_id
         self.timeout = timeout
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/assert_topic_latency.py b/scenario_execution_ros/scenario_execution_ros/actions/assert_topic_latency.py
index 601fade6..7ac038d7 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/assert_topic_latency.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/assert_topic_latency.py
@@ -21,7 +21,7 @@
 import importlib
 import time
 from scenario_execution_ros.actions.conversions import get_comparison_operator, get_qos_preset_profile
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class AssertTopicLatency(BaseAction):
@@ -51,17 +51,17 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         success = self.check_topic()
         if not success and self.wait_for_first_message:
-            raise ValueError("Invalid topic or type specified.")
+            raise ActionError("Invalid topic or type specified.", action=self)
         elif not success and not self.wait_for_first_message:
-            raise ValueError("Topic type must be specified. Please provide a valid topic type.")
+            raise ActionError("Topic type must be specified. Please provide a valid topic type.", action=self)
 
     def execute(self, topic_name: str, topic_type: str, latency: float, comparison_operator: bool, rolling_average_count: int, wait_for_first_message: bool):
         if self.timer != 0:
-            raise ValueError("Action does not yet support to get retriggered")
+            raise ActionError("Action does not yet support to get retriggered", action=self)
         self.timer = time.time()
 
     def update(self) -> py_trees.common.Status:
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/odometry_distance_traveled.py b/scenario_execution_ros/scenario_execution_ros/actions/odometry_distance_traveled.py
index d821e067..e2fa6b52 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/odometry_distance_traveled.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/odometry_distance_traveled.py
@@ -19,7 +19,7 @@
 from nav_msgs.msg import Odometry
 from py_trees.common import Status
 import py_trees
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class OdometryDistanceTraveled(BaseAction):
@@ -49,7 +49,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
         self.callback_group = rclpy.callback_groups.MutuallyExclusiveCallbackGroup()
         namespace = self.namespace
         if self.namespace_override:
@@ -59,7 +59,7 @@ def setup(self, **kwargs):
 
     def execute(self, associated_actor, distance: float, namespace_override: str):
         if self.namespace != associated_actor["namespace"] or self.namespace_override != namespace_override:
-            raise ValueError("Runtime change of namespace not supported.")
+            raise ActionError("Runtime change of namespace not supported.", action=self)
         self.distance_expected = distance
         self.distance_traveled = 0.0
         self.previous_x = 0
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_action_call.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_action_call.py
index b906f537..d8dcd8e6 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_action_call.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_action_call.py
@@ -24,7 +24,7 @@
 from rosidl_runtime_py.set_message import set_message_fields
 import py_trees  # pylint: disable=import-error
 from action_msgs.msg import GoalStatus
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class ActionCallActionState(Enum):
@@ -69,7 +69,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         datatype_in_list = self.action_type_string.split(".")
         try:
@@ -77,7 +77,7 @@ def setup(self, **kwargs):
                 importlib.import_module(".".join(datatype_in_list[0:-1])),
                 datatype_in_list[-1])
         except ValueError as e:
-            raise ValueError(f"Invalid action_type '{self.action_type}':") from e
+            raise ActionError(f"Invalid action_type '{self.action_type}': {e}", action=self) from e
 
         client_kwargs = {
             "callback_group": self.cb_group,
@@ -92,7 +92,7 @@ def setup(self, **kwargs):
 
     def execute(self, action_name: str, action_type: str, data: str, transient_local: bool = False):
         if self.action_name != action_name or self.action_type_string != action_type or self.transient_local != transient_local:
-            raise ValueError(f"Updating action_name or action_type_string not supported.")
+            raise ActionError(f"Updating action_name or action_type_string not supported.", action=self)
 
         self.parse_data(data)
         self.current_state = ActionCallActionState.IDLE
@@ -103,7 +103,7 @@ def parse_data(self, data):
                 trimmed_data = data.encode('utf-8').decode('unicode_escape')
                 self.data = literal_eval(trimmed_data)
             except Exception as e:  # pylint: disable=broad-except
-                raise ValueError(f"Error while parsing sevice call data:") from e
+                raise ActionError(f"Error while parsing sevice call data:", action=self) from e
 
     def update(self) -> py_trees.common.Status:
         """
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_bag_record.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_bag_record.py
index a40ae23b..f10659db 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_bag_record.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_bag_record.py
@@ -19,6 +19,7 @@
 from enum import Enum
 
 import py_trees
+from scenario_execution.actions.base_action import ActionError
 from scenario_execution.actions.run_process import RunProcess
 import shutil
 import signal
@@ -50,12 +51,11 @@ def setup(self, **kwargs):
         set up
         """
         if "output_dir" not in kwargs:
-            raise ValueError("output_dir not defined.")
+            raise ActionError("output_dir not defined.", action=self)
 
         if kwargs['output_dir']:
             if not os.path.exists(kwargs['output_dir']):
-                raise ValueError(
-                    f"Specified destination dir '{kwargs['output_dir']}' does not exist")
+                raise ActionError(f"Specified destination dir '{kwargs['output_dir']}' does not exist", action=self)
             self.output_dir = kwargs['output_dir']
 
     def execute(self, topics: list, timestamp_suffix: bool, hidden_topics: bool, storage: str, use_sim_time: bool):  # pylint: disable=arguments-differ
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_launch.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_launch.py
index d546d691..bfb72396 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_launch.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_launch.py
@@ -14,6 +14,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+from scenario_execution.actions.base_action import ActionError
 from scenario_execution.actions.run_process import RunProcess
 import signal
 
@@ -29,7 +30,7 @@ def execute(self, package_name: str, launch_file: str, arguments: list, wait_for
         if isinstance(arguments, list):
             for arg in arguments:
                 if 'key' not in arg or 'value' not in arg:
-                    raise ValueError(f'Invalid argument: {arg}')
+                    raise ActionError(f'Invalid argument: {arg}', action=self)
                 if arg["key"] is not None:
                     self.command.append(f'{arg["key"]}:={arg["value"]}')
         self.logger.info(f'Command: {" ".join(self.command)}')
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_log_check.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_log_check.py
index 617b6a16..dc557f92 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_log_check.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_log_check.py
@@ -19,7 +19,7 @@
 import rclpy
 from rcl_interfaces.msg import Log
 from py_trees.common import Status
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class RosLogCheck(BaseAction):
@@ -48,7 +48,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         topic_qos = QoSProfile(
             depth=100,
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_service_call.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_service_call.py
index 7a3b5af8..0f84a27d 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_service_call.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_service_call.py
@@ -22,7 +22,7 @@
 from rclpy.qos import QoSProfile, DurabilityPolicy
 from rosidl_runtime_py.set_message import set_message_fields
 import py_trees  # pylint: disable=import-error
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class ServiceCallActionState(Enum):
@@ -68,7 +68,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         datatype_in_list = self.service_type_str.split(".")
         try:
@@ -76,7 +76,7 @@ def setup(self, **kwargs):
                 importlib.import_module(".".join(datatype_in_list[0:-1])),
                 datatype_in_list[-1])
         except ValueError as e:
-            raise ValueError(f"Invalid service_type '{self.service_type}':") from e
+            raise ActionError(f"Invalid service_type '{self.service_type}': {e}", action=self) from e
 
         client_kwargs = {
             "callback_group": self.cb_group,
@@ -95,7 +95,7 @@ def setup(self, **kwargs):
 
     def execute(self,  service_name: str, service_type: str, data: str, transient_local: bool):
         if self.service_name != service_name or self.service_type_str != service_type or self.data_str != data or self.transient_local != transient_local:
-            raise ValueError("service_name, service_type and data arguments are not changeable during runtime.")
+            raise ActionError("service_name, service_type and data arguments are not changeable during runtime.", action=self)
         self.current_state = ServiceCallActionState.IDLE
 
     def update(self) -> py_trees.common.Status:
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_set_node_parameter.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_set_node_parameter.py
index 3464ad7c..dfda1c66 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_set_node_parameter.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_set_node_parameter.py
@@ -18,6 +18,7 @@
 
 from .ros_service_call import RosServiceCall
 from rcl_interfaces.msg import ParameterType
+from scenario_execution.actions.base_action import ActionError
 
 
 class RosSetNodeParameter(RosServiceCall):
@@ -70,7 +71,7 @@ def __init__(self, node_name: str, parameter_name: str, parameter_value: str):
 
     def execute(self, node_name: str, parameter_name: str, parameter_value: str):   # pylint: disable=arguments-differ,arguments-renamed
         if self.node_name != node_name or self.parameter_name != parameter_name or self.parameter_value != parameter_value:
-            raise ValueError("node_name, parameter_name and parameter_value are not changeable during runtime.")
+            raise ActionError("node_name, parameter_name and parameter_value are not changeable during runtime.", action=self)
 
     @staticmethod
     def is_float(element: any) -> bool:
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_check_data.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_check_data.py
index d1c1255c..74fa9e84 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_check_data.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_check_data.py
@@ -21,7 +21,7 @@
 from rosidl_runtime_py.set_message import set_message_fields
 from scenario_execution_ros.actions.conversions import get_qos_preset_profile, get_comparison_operator, get_ros_message_type
 import builtins
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class RosTopicCheckData(BaseAction):
@@ -61,7 +61,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         self.subscriber = self.node.create_subscription(
             msg_type=get_ros_message_type(self.topic_type),
@@ -83,7 +83,7 @@ def execute(self,
                 fail_if_bad_comparison: bool,
                 wait_for_first_message: bool):
         if self.topic_name != topic_name or self.topic_type != topic_type or self.qos_profile != qos_profile:
-            raise ValueError("Updating topic parameters not supported.")
+            raise ActionError("Updating topic parameters not supported.", action=self)
         self.member_name = member_name
         self.set_expected_value(expected_value)
         self.comparison_operator = get_comparison_operator(comparison_operator)
@@ -130,7 +130,7 @@ def check_data(self, msg):
 
     def set_expected_value(self, expected_value_string):
         if not isinstance(expected_value_string, str):
-            raise ValueError("Only string allowed as expected_value.")
+            raise ActionError("Only string allowed as expected_value.", action=self)
         error_string = ""
         try:
             parsed_value = literal_eval("".join(expected_value_string.split('\\')))
@@ -146,4 +146,4 @@ def set_expected_value(self, expected_value_string):
                 else:
                     set_message_fields(self.expected_value, parsed_value)
         except TypeError as e:
-            raise ValueError(f"Could not parse '{expected_value_string}'. {error_string}") from e
+            raise ActionError(f"Could not parse '{expected_value_string}'. {error_string}", action=self) from e
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_monitor.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_monitor.py
index 1279c0d5..714baa29 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_monitor.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_monitor.py
@@ -15,7 +15,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from scenario_execution_ros.actions.conversions import get_qos_preset_profile, get_ros_message_type
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 from scenario_execution.model.types import VariableReference
 import rclpy
 import py_trees
@@ -43,7 +43,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         msg_type = get_ros_message_type(self.topic_type)
 
@@ -61,9 +61,9 @@ def setup(self, **kwargs):
 
     def execute(self, topic_name: str, topic_type: str, member_name: str, target_variable: object, qos_profile: tuple):
         if self.topic_name != topic_name or self.topic_type != topic_type or self.qos_profile != qos_profile:
-            raise ValueError("Updating topic parameters not supported.")
+            raise ActionError("Updating topic parameters not supported.", action=self)
         if not isinstance(target_variable, VariableReference):
-            raise ValueError(f"'target_variable' is expected to be a variable reference.")
+            raise ActionError(f"'target_variable' is expected to be a variable reference.", action=self)
         self.target_variable = target_variable
         self.member_name = member_name
 
@@ -80,6 +80,6 @@ def get_value(self, msg):
             try:
                 return check_attr(msg)
             except AttributeError as e:
-                raise ValueError(f"invalid member_name '{self.member_name}'") from e
+                raise ActionError(f"invalid member_name '{self.member_name}'", action=self) from e
         else:
             return msg
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_publish.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_publish.py
index 8d4baf8c..def6cad2 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_publish.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_publish.py
@@ -23,7 +23,7 @@
 from py_trees.common import Status
 
 from scenario_execution_ros.actions.conversions import get_qos_preset_profile, get_ros_message_type
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class RosTopicPublish(BaseAction):
@@ -31,7 +31,7 @@ class RosTopicPublish(BaseAction):
     class for publish a message on a ROS topic
     """
 
-    def __init__(self, topic_type: str, topic_name: str, value: str, qos_profile: tuple):
+    def __init__(self, topic_type: str, topic_name: str, qos_profile: tuple):
         super().__init__()
         self.qos_profile = qos_profile
         self.topic_type = topic_type
@@ -48,24 +48,27 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
-        topic_type = get_ros_message_type(self.topic_type)
-        self.msg_to_pub = topic_type()
-        self.publisher = self.node.create_publisher(
-            msg_type=topic_type,
-            topic=self.topic_name,
-            qos_profile=get_qos_preset_profile(self.qos_profile)
-        )
+        try:
+            topic_type = get_ros_message_type(self.topic_type)
+            self.msg_to_pub = topic_type()
+            self.publisher = self.node.create_publisher(
+                msg_type=topic_type,
+                topic=self.topic_name,
+                qos_profile=get_qos_preset_profile(self.qos_profile)
+            )
+        except ValueError as e:
+            raise ActionError(f"{e}", action=self) from e
 
     def execute(self, topic_type: str, topic_name: str, value: str, qos_profile: tuple):
         if self.topic_name != topic_name or self.topic_type != topic_type or self.qos_profile != qos_profile:
-            raise ValueError("Updating topic parameters not supported.")
+            raise ActionError("Updating topic parameters not supported.", action=self)
 
         if isinstance(value, str):
             parsed_value = literal_eval("".join(value.split('\\')))
             if not isinstance(parsed_value, dict):
-                raise TypeError(f'Parsed value needs type "dict", got {type(parsed_value)}.')
+                raise ActionError(f'Parsed value needs type "dict", got {type(parsed_value)}.', action=self)
             set_message_fields(self.msg_to_pub, parsed_value)
         elif isinstance(value, dict):
             set_message_fields(self.msg_to_pub, value)
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_data.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_data.py
index f45cadc9..e0bec33f 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_data.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_data.py
@@ -15,7 +15,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from scenario_execution_ros.actions.conversions import get_qos_preset_profile, get_ros_message_type
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 import rclpy
 import py_trees
 
@@ -48,7 +48,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         self.subscriber = self.node.create_subscription(
             msg_type=get_ros_message_type(self.topic_type),
@@ -61,7 +61,7 @@ def setup(self, **kwargs):
 
     def execute(self, topic_name, topic_type, qos_profile):
         if self.topic_name != topic_name or self.topic_type != topic_type or self.qos_profile != qos_profile:
-            raise ValueError("Updating topic parameters not supported.")
+            raise ActionError("Updating topic parameters not supported.", action=self)
         self.found = False
 
     def update(self) -> py_trees.common.Status:
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_topics.py b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_topics.py
index 58202f5e..3f67a134 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_topics.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/ros_topic_wait_for_topics.py
@@ -16,7 +16,7 @@
 
 import py_trees
 from rclpy.node import Node
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class RosTopicWaitForTopics(BaseAction):
@@ -41,7 +41,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
     def update(self) -> py_trees.common.Status:
         """
diff --git a/scenario_execution_ros/scenario_execution_ros/actions/tf_close_to.py b/scenario_execution_ros/scenario_execution_ros/actions/tf_close_to.py
index ae81c385..7eb668e5 100644
--- a/scenario_execution_ros/scenario_execution_ros/actions/tf_close_to.py
+++ b/scenario_execution_ros/scenario_execution_ros/actions/tf_close_to.py
@@ -27,7 +27,7 @@
 from tf2_ros import TransformException  # pylint: disable= no-name-in-module
 
 from .common import NamespacedTransformListener
-from scenario_execution.actions.base_action import BaseAction
+from scenario_execution.actions.base_action import BaseAction, ActionError
 
 
 class TfCloseTo(BaseAction):
@@ -79,7 +79,7 @@ def setup(self, **kwargs):
         except KeyError as e:
             error_message = "didn't find 'node' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__)
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
 
         try:
             self.marker_handler = kwargs['marker_handler']
@@ -87,7 +87,7 @@ def setup(self, **kwargs):
             error_message = "didn't find 'marker_handler' in setup's kwargs [{}][{}]".format(
                 self.name, self.__class__.__name__
             )
-            raise KeyError(error_message) from e
+            raise ActionError(error_message, action=self) from e
         self.feedback_message = f"Waiting for transform map --> base_link"  # pylint: disable= attribute-defined-outside-init
         self.tf_buffer = Buffer()
         tf_prefix = self.namespace
diff --git a/scenario_execution_ros/scenario_execution_ros/external_methods/__init__.py b/scenario_execution_ros/scenario_execution_ros/external_methods/__init__.py
new file mode 100644
index 00000000..3ba13780
--- /dev/null
+++ b/scenario_execution_ros/scenario_execution_ros/external_methods/__init__.py
@@ -0,0 +1,15 @@
+# Copyright (C) 2024 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
diff --git a/scenario_execution_ros/scenario_execution_ros/external_methods/msg_conversion.py b/scenario_execution_ros/scenario_execution_ros/external_methods/msg_conversion.py
new file mode 100644
index 00000000..1cbb9f17
--- /dev/null
+++ b/scenario_execution_ros/scenario_execution_ros/external_methods/msg_conversion.py
@@ -0,0 +1,50 @@
+# Copyright (C) 2024 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+from geometry_msgs.msg import PoseWithCovarianceStamped
+import json
+from rosidl_runtime_py.convert import message_to_ordereddict
+
+from transforms3d.euler import quat2euler
+
+
+def get_object_member(in_value, member_name=""):
+    target = in_value
+    if member_name:
+        splitted_member = member_name.split('.')
+        for mem in splitted_member:
+            if not hasattr(target, mem):
+                raise ValueError(f"Member '{mem}' not found in '{target}")
+            target = getattr(target, mem)
+    return target
+
+
+def to_dict(in_value, member_name=""):
+    target = get_object_member(in_value, member_name)
+    return json.loads(json.dumps(message_to_ordereddict(target)))
+
+
+def to_pose_3d(in_value):
+    if isinstance(in_value, PoseWithCovarianceStamped):
+        pose3d = {}
+        pose3d["position"] = to_dict(in_value.pose.pose.position)
+        roll, pitch, yaw = quat2euler([in_value.pose.pose.orientation.w, in_value.pose.pose.orientation.x,
+                                      in_value.pose.pose.orientation.y, in_value.pose.pose.orientation.z])
+        pose3d["orientation"] = {'roll': roll, 'pitch': pitch, 'yaw': yaw}
+        return pose3d
+    elif isinstance(in_value, dict) and in_value == {}:  # allow empty input to enable expression evaluation
+        return in_value
+    else:
+        raise ValueError(f"to_pose3d not implemented for type {type(in_value)}")
diff --git a/scenario_execution_ros/scenario_execution_ros/lib_osc/ros.osc b/scenario_execution_ros/scenario_execution_ros/lib_osc/ros.osc
index e74b003b..18ae923d 100644
--- a/scenario_execution_ros/scenario_execution_ros/lib_osc/ros.osc
+++ b/scenario_execution_ros/scenario_execution_ros/lib_osc/ros.osc
@@ -26,7 +26,11 @@ enum lifecycle_state: [
 
 actor differential_drive_robot inherits robot:
     namespace: string = ''
-    
+
+struct msg_conversion:
+    def get_object_member(in_value: string, member_name: string = "") -> string is external scenario_execution_ros.external_methods.msg_conversion.get_object_member()
+    def to_pose_3d(in_value: string) -> pose_3d is external scenario_execution_ros.external_methods.msg_conversion.to_pose_3d()
+
 action action_call:
     # Call a ros action and wait for the result
     action_name: string                  # name of the action to connect to
diff --git a/scenario_execution_ros/test/test_external_methods_msg_conversion.py b/scenario_execution_ros/test/test_external_methods_msg_conversion.py
new file mode 100644
index 00000000..58fe1728
--- /dev/null
+++ b/scenario_execution_ros/test/test_external_methods_msg_conversion.py
@@ -0,0 +1,102 @@
+# Copyright (C) 2024 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+
+import os
+import unittest
+import rclpy
+import py_trees
+from scenario_execution_ros import ROSScenarioExecution
+from scenario_execution.model.osc2_parser import OpenScenario2Parser
+from scenario_execution.model.model_to_py_tree import create_py_tree
+from scenario_execution.model.model_blackboard import create_py_tree_blackboard
+from scenario_execution.utils.logging import Logger
+from antlr4.InputStream import InputStream
+
+os.environ["PYTHONUNBUFFERED"] = '1'
+
+
+class TestExternalMethodsMsgConversion(unittest.TestCase):
+    # pylint: disable=missing-function-docstring
+
+    def setUp(self):
+        rclpy.init()
+        self.parser = OpenScenario2Parser(Logger('test', False))
+        self.scenario_execution_ros = ROSScenarioExecution()
+        self.tree = py_trees.composites.Sequence(name="", memory=True)
+
+    def execute(self, scenario_content):
+        parsed_tree = self.parser.parse_input_stream(InputStream(scenario_content))
+        model = self.parser.create_internal_model(parsed_tree, self.tree, "test.osc", False)
+        create_py_tree_blackboard(model, self.tree, self.parser.logger, False)
+        self.tree = create_py_tree(model, self.tree, self.parser.logger, False)
+        self.scenario_execution_ros.tree = self.tree
+        self.scenario_execution_ros.run()
+
+    def tearDown(self):
+        rclpy.try_shutdown()
+
+    def test_get_object_member(self):
+        scenario_content = """
+import osc.ros
+import osc.helpers
+
+struct current_state:
+    var test_pose: string
+
+scenario test_success:
+    timeout(10s)
+    current: current_state
+    
+    do parallel:
+        topic_monitor('/test_pose', 'geometry_msgs.msg.PoseWithCovarianceStamped', current.test_pose)
+        serial:
+            wait elapsed(0.5s)
+            topic_publish('/test_pose', 'geometry_msgs.msg.PoseWithCovarianceStamped', "{ \\\'pose\\\': { \\\'pose\\\': { \\\'position\\\': { \\\'x\\\': 42 }}}}")
+        serial:
+            wait elapsed(3s)
+            topic_publish('/pose_only', 'geometry_msgs.msg.Pose', msg_conversion.get_object_member(current.test_pose, "pose.pose"))
+
+        serial:
+            check_data('/pose_only', 'geometry_msgs.msg.Pose', expected_value: '{ \\\"position\\\": { \\\"x\\\": 42 }}')
+            emit end
+"""
+        self.execute(scenario_content)
+        self.assertTrue(self.scenario_execution_ros.process_results())
+
+    def test_to_pose_3d(self):
+        scenario_content = """
+import osc.ros
+import osc.helpers
+
+struct current_state:
+    var test_pose: string
+
+scenario test_success:
+    timeout(10s)
+    current: current_state
+    test_pose : pose_3d = pose_3d(position_3d(x: 42))
+    do parallel:
+        topic_monitor('/test_pose', 'geometry_msgs.msg.PoseWithCovarianceStamped', current.test_pose)
+        serial:
+            wait elapsed(0.5s)
+            topic_publish('/test_pose', 'geometry_msgs.msg.PoseWithCovarianceStamped', "{ \\\'pose\\\': { \\\'pose\\\': { \\\'position\\\': { \\\'x\\\': 42 }, \\\'orientation\\\': { \\\'w\\\': 1 }}}}")
+        serial:
+            wait test_pose == msg_conversion.to_pose_3d(current.test_pose)
+            emit end
+"""
+        self.execute(scenario_content)
+        self.assertTrue(self.scenario_execution_ros.process_results())