diff --git a/vitrage/common/constants.py b/vitrage/common/constants.py
index a99821f58..f32cceb7e 100644
--- a/vitrage/common/constants.py
+++ b/vitrage/common/constants.py
@@ -57,14 +57,11 @@ class EdgeLabel(object):
     MANAGED_BY = 'managed_by'
     COMPRISED = 'comprised'
 
-edge_labels = [EdgeLabel.ON,
-               EdgeLabel.CONTAINS,
-               EdgeLabel.CAUSES,
-               EdgeLabel.ATTACHED,
-               EdgeLabel.ATTACHED_PRIVATE,
-               EdgeLabel.ATTACHED_PUBLIC,
-               EdgeLabel.CONNECT,
-               EdgeLabel.MANAGED_BY]
+    @staticmethod
+    def labels():
+        return [EdgeLabel.__dict__[label]
+                for label in vars(EdgeLabel)
+                if not label.startswith(('_', 'labels'))]
 
 
 class SyncMode(object):
@@ -83,9 +80,11 @@ class EntityCategory(object):
     RESOURCE = 'RESOURCE'
     ALARM = 'ALARM'
 
-
-entities_categories = [EntityCategory.RESOURCE,
-                       EntityCategory.ALARM]
+    @staticmethod
+    def categories():
+        return [EntityCategory.__dict__[category]
+                for category in vars(EntityCategory)
+                if not category.startswith(('_', 'categories'))]
 
 
 class DatasourceProperties(object):
diff --git a/vitrage/evaluator/template_validation/status_messages.py b/vitrage/evaluator/template_validation/status_messages.py
index 2885d5d4f..f95862653 100644
--- a/vitrage/evaluator/template_validation/status_messages.py
+++ b/vitrage/evaluator/template_validation/status_messages.py
@@ -11,8 +11,8 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
-from vitrage.common.constants import edge_labels
-from vitrage.common.constants import entities_categories
+from vitrage.common.constants import EdgeLabel
+from vitrage.common.constants import EntityCategory
 from vitrage.evaluator.actions.base import action_types
 
 status_msgs = {
@@ -33,7 +33,7 @@ status_msgs = {
     42: 'Entity definition must contain category field.',
     43: 'At least one entity must be defined.',
     45: 'Invalid entity category. Category must be from types: '
-        '%s' % entities_categories,
+        '{categories}'.format(categories=EntityCategory.categories()),
     46: 'Entity field is required.',
 
     # metadata section status messages 60-79
@@ -50,7 +50,7 @@ status_msgs = {
 
     # relationships status messages 100-119
     100: 'Invalid relation type. Relation type must be from types: '
-         '%s' % edge_labels,
+         '{labels}'.format(labels=EdgeLabel.labels()),
     101: 'Relationship field is required.',
     102: 'Relationship definition must contain source field.',
     103: 'Relationship definition must contain target field.',
@@ -58,7 +58,7 @@ status_msgs = {
 
     # actions status messages 120-139
     120: 'Invalid action type. Action type must be from types: '
-         '%s' % action_types,
+         '{actions}'.format(actions=action_types),
     121: 'At least one action must be defined.',
     122: 'Action field is required.',
     123: 'Relationship definition must contain action_type field.',
diff --git a/vitrage/evaluator/template_validation/template_syntax_validator.py b/vitrage/evaluator/template_validation/template_syntax_validator.py
index c29c7be48..a28a2ec9e 100644
--- a/vitrage/evaluator/template_validation/template_syntax_validator.py
+++ b/vitrage/evaluator/template_validation/template_syntax_validator.py
@@ -22,8 +22,8 @@ from voluptuous import Invalid
 from voluptuous import Required
 from voluptuous import Schema
 
-from vitrage.common.constants import edge_labels
-from vitrage.common.constants import entities_categories
+from vitrage.common.constants import EdgeLabel
+from vitrage.common.constants import EntityCategory
 from vitrage.evaluator.actions.base import action_types
 from vitrage.evaluator.template_fields import TemplateFields
 from vitrage.evaluator.template_validation.base import get_correct_result
@@ -269,7 +269,7 @@ def _validate_template_id_value(msg=None):
 
 def _validate_category_field(msg=None):
     def f(v):
-        if str(v) in entities_categories:
+        if str(v) in EntityCategory.categories():
             return str(v)
         else:
             raise Invalid(msg or 45)
@@ -278,7 +278,7 @@ def _validate_category_field(msg=None):
 
 def _validate_relationship_type_field(msg=None):
     def f(v):
-        if str(v) in edge_labels:
+        if str(v) in EdgeLabel.labels():
             return str(v)
         else:
             raise Invalid(msg or 100)