diff --git a/mistral/engine/base.py b/mistral/engine/base.py
index d3d22195..63e0f857 100644
--- a/mistral/engine/base.py
+++ b/mistral/engine/base.py
@@ -69,28 +69,41 @@ class Engine(object):
         raise NotImplementedError
 
     @abc.abstractmethod
-    def pause_workflow(self, execution_id):
-        """Pauses workflow execution.
+    def pause_workflow(self, wf_ex_id):
+        """Pauses workflow.
 
-        :param execution_id: Execution id.
+        :param wf_ex_id: Execution id.
         :return: Workflow execution object.
         """
         raise NotImplementedError
 
     @abc.abstractmethod
-    def resume_workflow(self, execution_id):
-        """Resumes workflow execution.
+    def resume_workflow(self, wf_ex_id):
+        """Resumes workflow.
 
-        :param execution_id: Execution id.
+        :param wf_ex_id: Execution id.
         :return: Workflow execution object.
         """
         raise NotImplementedError
 
     @abc.abstractmethod
-    def stop_workflow(self, execution_id, state, message):
-        """Stops workflow execution.
+    def rerun_workflow(self, wf_ex_id, task_ex_id, reset=True, env=None):
+        """Rerun workflow from the specified task.
 
-        :param execution_id: Workflow execution id.
+        :param wf_ex_id: Workflow execution id.
+        :param task_ex_id: Task execution id.
+        :param reset: If True, reset task state including deleting its action
+            executions.
+        :param env: Workflow environment.
+        :return: Workflow execution object.
+        """
+        raise NotImplementedError
+
+    @abc.abstractmethod
+    def stop_workflow(self, wf_ex_id, state, message):
+        """Stops workflow.
+
+        :param wf_ex_id: Workflow execution id.
         :param state: State assigned to the workflow. Permitted states are
             SUCCESS or ERROR.
         :param message: Optional information string.
@@ -100,10 +113,10 @@ class Engine(object):
         raise NotImplementedError
 
     @abc.abstractmethod
-    def rollback_workflow(self, execution_id):
+    def rollback_workflow(self, wf_ex_id):
         """Rolls back workflow execution.
 
-        :param execution_id: Execution id.
+        :param wf_ex_id: Execution id.
         :return: Workflow execution object.
         """
         raise NotImplementedError
diff --git a/mistral/engine/default_engine.py b/mistral/engine/default_engine.py
index f71adc1a..944e25e7 100644
--- a/mistral/engine/default_engine.py
+++ b/mistral/engine/default_engine.py
@@ -275,9 +275,9 @@ class DefaultEngine(base.Engine, coordination.Service):
             raise e
 
     @u.log_exec(LOG)
-    def pause_workflow(self, execution_id):
+    def pause_workflow(self, wf_ex_id):
         with db_api.transaction():
-            wf_ex = wf_handler.lock_workflow_execution(execution_id)
+            wf_ex = wf_handler.lock_workflow_execution(wf_ex_id)
 
             wf_handler.set_execution_state(wf_ex, states.PAUSED)
 
diff --git a/mistral/engine/rpc.py b/mistral/engine/rpc.py
index b9598263..41a35381 100644
--- a/mistral/engine/rpc.py
+++ b/mistral/engine/rpc.py
@@ -140,6 +140,10 @@ class EngineServer(object):
         """Receives calls over RPC to start workflows on engine.
 
         :param rpc_ctx: RPC request context.
+        :param workflow_identifier: Workflow definition identifier.
+        :param workflow_input: Workflow input.
+        :param description: Workflow execution description.
+        :param params: Additional workflow type specific parameters.
         :return: Workflow execution.
         """
 
@@ -398,6 +402,8 @@ class EngineClient(base.Engine):
         it possibly needs to move the workflow on, i.e. run other workflow
         tasks for which all dependencies are satisfied.
 
+        :param action_ex_id: Action execution id.
+        :param result: Action execution result.
         :return: Task.
         """
 
@@ -410,16 +416,17 @@ class EngineClient(base.Engine):
         )
 
     @wrap_messaging_exception
-    def pause_workflow(self, execution_id):
+    def pause_workflow(self, wf_ex_id):
         """Stops the workflow with the given execution id.
 
+        :param wf_ex_id: Workflow execution id.
         :return: Workflow execution.
         """
 
         return self._client.call(
             auth_ctx.ctx(),
             'pause_workflow',
-            execution_id=execution_id
+            execution_id=wf_ex_id
         )
 
     @wrap_messaging_exception
@@ -431,7 +438,8 @@ class EngineClient(base.Engine):
 
         :param wf_ex_id: Workflow execution id.
         :param task_ex_id: Task execution id.
-        :param reset: If true, then purge action execution for the task.
+        :param reset: If true, then reset task execution state and purge
+            action execution for the task.
         :param env: Environment variables to update.
         :return: Workflow execution.
         """
@@ -462,13 +470,13 @@ class EngineClient(base.Engine):
         )
 
     @wrap_messaging_exception
-    def stop_workflow(self, execution_id, state, message=None):
+    def stop_workflow(self, wf_ex_id, state, message=None):
         """Stops workflow execution with given status.
 
         Once stopped, the workflow is complete with SUCCESS or ERROR,
         and can not be resumed.
 
-        :param execution_id: Workflow execution id
+        :param wf_ex_id: Workflow execution id
         :param state: State assigned to the workflow: SUCCESS or ERROR
         :param message: Optional information string
 
@@ -478,22 +486,24 @@ class EngineClient(base.Engine):
         return self._client.call(
             auth_ctx.ctx(),
             'stop_workflow',
-            execution_id=execution_id,
+            execution_id=wf_ex_id,
             state=state,
             message=message
         )
 
     @wrap_messaging_exception
-    def rollback_workflow(self, execution_id):
+    def rollback_workflow(self, wf_ex_id):
         """Rolls back the workflow with the given execution id.
 
+        :param wf_ex_id: Workflow execution id.
+
         :return: Workflow execution.
         """
 
         return self._client.call(
             auth_ctx.ctx(),
             'rollback_workflow',
-            execution_id=execution_id
+            execution_id=wf_ex_id
         )
 
 
@@ -508,6 +518,11 @@ class ExecutorServer(object):
         """Receives calls over RPC to run action on executor.
 
         :param rpc_ctx: RPC request context dictionary.
+        :param action_ex_id: Action execution id.
+        :param action_class_str: Action class name.
+        :param attributes: Action class attributes.
+        :param params: Action input parameters.
+        :return: Action result.
         """
 
         LOG.info(
@@ -546,7 +561,17 @@ class ExecutorClient(base.Executor):
 
     def run_action(self, action_ex_id, action_class_str, attributes,
                    action_params, target=None, async=True):
-        """Sends a request to run action to executor."""
+        """Sends a request to run action to executor.
+
+        :param action_ex_id: Action execution id.
+        :param action_class_str: Action class name.
+        :param attributes: Action class attributes.
+        :param action_params: Action input parameters.
+        :param target: Target (group of action executors).
+        :param async: If True, run action in asynchronous mode (w/o waiting
+            for completion).
+        :return: Action result.
+        """
 
         kwargs = {
             'action_ex_id': action_ex_id,