diff --git a/watcher/tests/decision_engine/model/data/scenario_1_with_all_nodes_disable.xml b/watcher/tests/decision_engine/model/data/scenario_1_with_all_nodes_disable.xml
new file mode 100644
index 000000000..9db3d1019
--- /dev/null
+++ b/watcher/tests/decision_engine/model/data/scenario_1_with_all_nodes_disable.xml
@@ -0,0 +1,9 @@
+<ModelRoot>
+  <ComputeNode hostname="hostname_0" uuid="Node_0" id="0" state="up" human_id="" status="disabled" vcpus="40" disk="250" disk_capacity="250" disabled_reason='watcher_disabled' memory="64">
+    <Instance watcher_exclude="False" human_id="" state="active" uuid="INSTANCE_0" vcpus="10" disk="20" disk_capacity="20" memory="2" metadata='{"optimize": true,"top": "floor", "nested": {"x": "y"}}' project_id="91FFFE30-78A0-4152-ACD2-8310FF274DC9"/>
+  </ComputeNode>
+  <ComputeNode hostname="hostname_1" uuid="Node_1" id="1" state="up" human_id="" status="disabled" vcpus="40" disk="250" disk_capacity="250" disabled_reason='watcher_disabled' memory="64">
+    <Instance watcher_exclude="False" human_id="" state="active" uuid="INSTANCE_1" vcpus="10" disk="20" disk_capacity="20" memory="2" metadata='{"optimize": true,"top": "floor", "nested": {"x": "y"}}' project_id="91FFFE30-78A0-4152-ACD2-8310FF274DC9"/>
+  </ComputeNode>
+</ModelRoot>
+
diff --git a/watcher/tests/decision_engine/model/faker_cluster_state.py b/watcher/tests/decision_engine/model/faker_cluster_state.py
index 66f2a4147..ee272ce45 100644
--- a/watcher/tests/decision_engine/model/faker_cluster_state.py
+++ b/watcher/tests/decision_engine/model/faker_cluster_state.py
@@ -136,6 +136,9 @@ class FakerModelCollector(base.BaseClusterDataModelCollector):
     def generate_scenario_1_with_1_node_unavailable(self):
         return self.load_model('scenario_1_with_1_node_unavailable.xml')
 
+    def generate_scenario_1_with_all_nodes_disable(self):
+        return self.load_model('scenario_1_with_all_nodes_disable.xml')
+
     def generate_scenario_1_with_all_instances_exclude(self):
         return self.load_model('scenario_1_with_all_instances_exclude.xml')
 
diff --git a/watcher/tests/decision_engine/strategy/strategies/test_host_maintenance.py b/watcher/tests/decision_engine/strategy/strategies/test_host_maintenance.py
index a1a962942..5171097d1 100755
--- a/watcher/tests/decision_engine/strategy/strategies/test_host_maintenance.py
+++ b/watcher/tests/decision_engine/strategy/strategies/test_host_maintenance.py
@@ -20,6 +20,7 @@
 import mock
 
 from watcher.common import exception
+from watcher.decision_engine.model import element
 from watcher.decision_engine.model import model_root
 from watcher.decision_engine.strategy import strategies
 from watcher.tests import base
@@ -60,6 +61,36 @@ class TestHostMaintenance(base.TestCase):
             exception.ClusterStateNotDefined,
             self.strategy.execute)
 
+    def test_get_instance_state_str(self):
+        mock_instance = mock.MagicMock(state="active")
+        self.assertEqual("active",
+                         self.strategy.get_instance_state_str(mock_instance))
+
+        mock_instance.state = element.InstanceState("active")
+        self.assertEqual("active",
+                         self.strategy.get_instance_state_str(mock_instance))
+
+        mock_instance.state = None
+        self.assertRaises(
+            exception.WatcherException,
+            self.strategy.get_instance_state_str,
+            mock_instance)
+
+    def test_get_node_status_str(self):
+        mock_node = mock.MagicMock(status="enabled")
+        self.assertEqual("enabled",
+                         self.strategy.get_node_status_str(mock_node))
+
+        mock_node.status = element.ServiceState("enabled")
+        self.assertEqual("enabled",
+                         self.strategy.get_node_status_str(mock_node))
+
+        mock_node.status = None
+        self.assertRaises(
+            exception.WatcherException,
+            self.strategy.get_node_status_str,
+            mock_node)
+
     def test_get_node_capacity(self):
         model = self.fake_cluster.generate_scenario_1()
         self.m_model.return_value = model
@@ -172,6 +203,11 @@ class TestHostMaintenance(base.TestCase):
         self.assertFalse(self.strategy.safe_maintain(node_0))
         self.assertFalse(self.strategy.safe_maintain(node_1))
 
+        model = self.fake_cluster.generate_scenario_1_with_all_nodes_disable()
+        self.m_model.return_value = model
+        node_0 = model.get_node_by_uuid('Node_0')
+        self.assertTrue(self.strategy.safe_maintain(node_0))
+
     def test_try_maintain(self):
         model = self.fake_cluster.generate_scenario_1()
         self.m_model.return_value = model
@@ -186,8 +222,14 @@ class TestHostMaintenance(base.TestCase):
         node_2 = model.get_node_by_uuid('Node_2')
         node_3 = model.get_node_by_uuid('Node_3')
         instance_4 = model.get_instance_by_uuid("INSTANCE_4")
-        if not self.strategy.safe_maintain(node_2, node_3):
-            self.strategy.try_maintain(node_2)
+
+        result = self.strategy.pre_execute()
+        self.assertIsNone(result)
+
+        self.strategy.input_parameters = {"maintenance_node": 'Node_2',
+                                          "backup_node": 'Node_3'}
+        self.strategy.do_execute()
+
         expected = [{'action_type': 'change_nova_service_state',
                      'input_parameters': {
                          'resource_id': 'Node_3',
@@ -204,3 +246,6 @@ class TestHostMaintenance(base.TestCase):
                          'migration_type': 'live',
                          'resource_id': instance_4.uuid}}]
         self.assertEqual(expected, self.strategy.solution.actions)
+
+        result = self.strategy.post_execute()
+        self.assertIsNone(result)