diff --git a/patrole_tempest_plugin/rbac_utils.py b/patrole_tempest_plugin/rbac_utils.py
index d5f1c2b..69c6ccd 100644
--- a/patrole_tempest_plugin/rbac_utils.py
+++ b/patrole_tempest_plugin/rbac_utils.py
@@ -55,32 +55,25 @@
                 cls.rbac_role_id = item['id']
             if item['name'] == 'admin':
                 cls.admin_role_id = item['id']
-        # Check if admin and rbac role exits
-        if not cls.admin_role_id or not cls.rbac_role_id:
-            msg = ("defined 'rbac_role' or 'admin' role does not exist"
-                   " in the system.")
-            raise rbac_exceptions.RbacResourceSetupFailed(msg)
-
-    def clear_user_roles(cls, user_id, tenant_id):
-        roles = cls.creds_client.roles_client.list_user_roles_on_project(
-            tenant_id, user_id)['roles']
-
-        for role in roles:
-            cls.creds_client.roles_client.delete_role_from_user_on_project(
-                tenant_id, user_id, role['id'])
 
     def switch_role(cls, test_obj, switchToRbacRole=None):
         LOG.debug('Switching role to: %s', switchToRbacRole)
+        # Check if admin and rbac roles exist.
+        if not cls.admin_role_id or not cls.rbac_role_id:
+            msg = ("Defined 'rbac_role' or 'admin' role does not exist"
+                   " in the system.")
+            raise rbac_exceptions.RbacResourceSetupFailed(msg)
+
         if not isinstance(switchToRbacRole, bool):
             msg = ("Wrong value for parameter 'switchToRbacRole' is passed."
                    " It should be either 'True' or 'False'.")
-            raise rbac_exceptions.RbacActionFailed(msg)
+            raise rbac_exceptions.RbacResourceSetupFailed(msg)
 
         try:
             user_id = test_obj.auth_provider.credentials.user_id
             project_id = test_obj.auth_provider.credentials.tenant_id
 
-            cls.clear_user_roles(user_id, project_id)
+            cls._clear_user_roles(user_id, project_id)
 
             if switchToRbacRole:
                 cls.creds_client.roles_client.create_user_role_on_project(
@@ -100,4 +93,12 @@
             time.sleep(1)
             test_obj.auth_provider.set_auth()
 
+    def _clear_user_roles(cls, user_id, tenant_id):
+        roles = cls.creds_client.roles_client.list_user_roles_on_project(
+            tenant_id, user_id)['roles']
+
+        for role in roles:
+            cls.creds_client.roles_client.delete_role_from_user_on_project(
+                tenant_id, user_id, role['id'])
+
 rbac_utils = RbacUtils
diff --git a/patrole_tempest_plugin/tests/unit/test_rbac_utils.py b/patrole_tempest_plugin/tests/unit/test_rbac_utils.py
index 9dd5985..add1770 100644
--- a/patrole_tempest_plugin/tests/unit/test_rbac_utils.py
+++ b/patrole_tempest_plugin/tests/unit/test_rbac_utils.py
@@ -15,45 +15,141 @@
 
 import mock
 
+from tempest import config
 from tempest.lib import exceptions as lib_exc
 from tempest.tests import base
 
 from patrole_tempest_plugin import rbac_exceptions
 from patrole_tempest_plugin import rbac_utils
 
+CONF = config.CONF
+
 
 class RBACUtilsTest(base.TestCase):
-    def setUp(self):
+
+    @mock.patch.object(rbac_utils, 'time', autospec=True)
+    def setUp(self, _):
         super(RBACUtilsTest, self).setUp()
-        mock_creds_provider = mock.patch.object(
-            rbac_utils, 'credentials_factory').start()
-        mock_creds_provider.get_credentials_provider.return_value.\
-            creds_client.roles_client.list_roles.return_value.\
-            __getitem__.return_value = [
+        self.mock_creds_provider = mock.patch.object(
+            rbac_utils, 'credentials_factory', autospec=True).start()
+
+        available_roles = {
+            'roles': [
                 {'name': 'admin', 'id': 'admin_id'},
                 {'name': 'Member', 'id': 'member_id'}
             ]
+        }
+        self.mock_creds_provider.get_credentials_provider.return_value.\
+            creds_client.roles_client.list_roles.return_value = \
+            available_roles
+        self.addCleanup(mock.patch.stopall)
+
+        CONF.set_override('rbac_test_role', 'Member', group='rbac',
+                          enforce_type=True)
+        self.addCleanup(CONF.clear_override, 'rbac_test_role', group='rbac')
+
+        # Because rbac_utils is a singleton, reset all of its role-related
+        # parameters to the correct values for each test run.
         self.rbac_utils = rbac_utils.rbac_utils()
+        self.rbac_utils.available_roles = available_roles
+        self.rbac_utils.admin_role_id = 'admin_id'
+        self.rbac_utils.rbac_role_id = 'member_id'
 
-    def test_rbac_utils_switch_roles_none(self):
-        self.assertRaises(rbac_exceptions.RbacActionFailed,
-                          self.rbac_utils.switch_role, None)
+    def test_initialization_with_missing_admin_role(self):
+        self.rbac_utils.admin_role_id = None
+        e = self.assertRaises(rbac_exceptions.RbacResourceSetupFailed,
+                              self.rbac_utils.switch_role, None)
+        self.assertIn("Defined 'rbac_role' or 'admin' role does not exist"
+                      " in the system.", e.__str__())
 
-    def test_rbac_utils_switch_roles_false(self):
-        self.auth_provider = mock.Mock()
-        self.auth_provider.credentials.user_id = "user_id"
-        self.auth_provider.credentials.tenant_id = "tenant_id"
-        self.admin_client = mock.Mock()
-        self.admin_client.token = "admin_token"
-        self.assertIsNone(self.rbac_utils.switch_role(self, False))
+    def test_initialization_with_missing_rbac_role(self):
+        self.rbac_utils.rbac_role_id = None
+        e = self.assertRaises(rbac_exceptions.RbacResourceSetupFailed,
+                              self.rbac_utils.switch_role, None)
+        self.assertIn("Defined 'rbac_role' or 'admin' role does not exist"
+                      " in the system.", e.__str__())
 
-    def test_rbac_utils_switch_roles_get_roles_fails(self):
-        self.auth_provider = mock.Mock()
-        self.auth_provider.credentials.user_id = "user_id"
-        self.auth_provider.credentials.tenant_id = "tenant_id"
-        self.admin_client = mock.Mock()
-        self.admin_client.token = "admin_token"
-        self.rbac_utils.creds_client.roles_client.create_user_role_on_project.\
-            side_effect = lib_exc.NotFound
-        self.assertRaises(lib_exc.NotFound, self.rbac_utils.switch_role, self,
-                          False)
+    def test_clear_user_roles(self):
+        self.rbac_utils.creds_client = mock.Mock()
+        creds_client = self.rbac_utils.creds_client
+        creds_client.roles_client.list_user_roles_on_project.return_value = {
+            'roles': [{'id': 'admin_id'}, {'id': 'member_id'}]
+        }
+
+        self.rbac_utils._clear_user_roles(mock.sentinel.user_id,
+                                          mock.sentinel.project_id)
+
+        creds_client.roles_client.list_user_roles_on_project.\
+            assert_called_once_with(mock.sentinel.project_id,
+                                    mock.sentinel.user_id)
+        creds_client.roles_client.delete_role_from_user_on_project.\
+            assert_has_calls([
+                mock.call(mock.sentinel.project_id, mock.sentinel.user_id,
+                          'admin_id'),
+                mock.call(mock.sentinel.project_id, mock.sentinel.user_id,
+                          'member_id'),
+            ])
+
+    @mock.patch.object(rbac_utils.rbac_utils, '_clear_user_roles',
+                       autospec=True)
+    def test_rbac_utils_switch_role_to_admin(self, mock_clear_user_roles):
+        mock_test_object = mock.Mock()
+        mock_test_object.auth_provider.credentials.user_id = \
+            mock.sentinel.user_id
+        mock_test_object.auth_provider.credentials.tenant_id = \
+            mock.sentinel.project_id
+
+        self.rbac_utils.creds_client = mock.Mock()
+        creds_client = self.rbac_utils.creds_client
+
+        self.rbac_utils.switch_role(mock_test_object, False)
+
+        creds_client.roles_client.create_user_role_on_project.\
+            assert_called_once_with(mock.sentinel.project_id,
+                                    mock.sentinel.user_id,
+                                    'admin_id')
+        mock_clear_user_roles.assert_called_once_with(
+            self.rbac_utils, mock.sentinel.user_id, mock.sentinel.project_id)
+        mock_test_object.auth_provider.clear_auth.assert_called_once_with()
+        mock_test_object.auth_provider.set_auth.assert_called_once_with()
+
+    @mock.patch.object(rbac_utils.rbac_utils, '_clear_user_roles',
+                       autospec=True)
+    def test_rbac_utils_switch_role_to_rbac_role(self, mock_clear_user_roles):
+        mock_test_object = mock.Mock()
+        mock_test_object.auth_provider.credentials.user_id = \
+            mock.sentinel.user_id
+        mock_test_object.auth_provider.credentials.tenant_id = \
+            mock.sentinel.project_id
+
+        self.rbac_utils.creds_client = mock.Mock()
+        creds_client = self.rbac_utils.creds_client
+
+        self.rbac_utils.switch_role(mock_test_object, True)
+
+        creds_client.roles_client.create_user_role_on_project.\
+            assert_called_once_with(mock.sentinel.project_id,
+                                    mock.sentinel.user_id,
+                                    'member_id')
+        mock_clear_user_roles.assert_called_once_with(
+            self.rbac_utils, mock.sentinel.user_id, mock.sentinel.project_id)
+        mock_test_object.auth_provider.clear_auth.assert_called_once_with()
+        mock_test_object.auth_provider.set_auth.assert_called_once_with()
+
+    def test_rbac_utils_switch_roles_with_invalid_value(self):
+        e = self.assertRaises(rbac_exceptions.RbacResourceSetupFailed,
+                              self.rbac_utils.switch_role, None)
+        self.assertIn("Wrong value for parameter 'switchToRbacRole' is passed."
+                      " It should be either 'True' or 'False'.", e.__str__())
+
+    @mock.patch.object(rbac_utils.rbac_utils, '_clear_user_roles',
+                       autospec=True)
+    def test_rbac_utils_switch_role_except_exception(self,
+                                                     mock_clear_user_roles):
+        self.rbac_utils.creds_client = mock.Mock()
+        creds_client = self.rbac_utils.creds_client
+        creds_client.roles_client.create_user_role_on_project.side_effect =\
+            lib_exc.NotFound
+
+        self.assertRaises(lib_exc.NotFound, self.rbac_utils.switch_role,
+                          mock.Mock(), True)