diff --git a/moto/swf/models/__init__.py b/moto/swf/models/__init__.py
index 4d70fbd0e..88e362f4e 100644
--- a/moto/swf/models/__init__.py
+++ b/moto/swf/models/__init__.py
@@ -243,7 +243,7 @@ class SWFBackend(BaseBackend):
             raise SWFValidationException("Invalid token")
         # decision task found, but WorflowExecution is CLOSED
         wfe = decision_task.workflow_execution
-        if wfe.execution_status != "OPEN":
+        if not wfe.open:
             raise SWFUnknownResourceFault(
                 "execution",
                 "WorkflowExecution=[workflowId={0}, runId={1}]".format(
@@ -331,7 +331,7 @@ class SWFBackend(BaseBackend):
             raise SWFValidationException("Invalid token")
         # activity task found, but WorflowExecution is CLOSED
         wfe = activity_task.workflow_execution
-        if wfe.execution_status != "OPEN":
+        if not wfe.open:
             raise SWFUnknownResourceFault(
                 "execution",
                 "WorkflowExecution=[workflowId={0}, runId={1}]".format(
diff --git a/moto/swf/models/domain.py b/moto/swf/models/domain.py
index 55bf1b8e8..824782c59 100644
--- a/moto/swf/models/domain.py
+++ b/moto/swf/models/domain.py
@@ -83,7 +83,7 @@ class Domain(object):
                     if w.workflow_id == workflow_id and w.run_id == run_id]
         else:
             _all = [w for w in self.workflow_executions
-                    if w.workflow_id == workflow_id and w.execution_status == "OPEN"]
+                    if w.workflow_id == workflow_id and w.open]
         # reduce
         wfe = _all[0] if _all else None
         # raise if closed / none
diff --git a/moto/swf/models/workflow_execution.py b/moto/swf/models/workflow_execution.py
index 3645b645d..aee678a1d 100644
--- a/moto/swf/models/workflow_execution.py
+++ b/moto/swf/models/workflow_execution.py
@@ -523,7 +523,7 @@ class WorkflowExecution(object):
         self.close_cause = "OPERATOR_INITIATED"
 
     def has_timedout(self):
-        if self.execution_status != "OPEN" or not self.start_timestamp:
+        if not self.open or not self.start_timestamp:
             return False
         # TODO: handle the "NONE" case
         start_to_close_timeout = self.start_timestamp + \
@@ -535,3 +535,7 @@ class WorkflowExecution(object):
             self.execution_status = "CLOSED"
             self.close_status = "TIMED_OUT"
             self.timeout_type = "START_TO_CLOSE"
+
+    @property
+    def open(self):
+        return self.execution_status == "OPEN"