diff --git a/rw_core/coreIf/device_manager_if.go b/rw_core/coreIf/device_manager_if.go
new file mode 100644
index 0000000..c8e33c1
--- /dev/null
+++ b/rw_core/coreIf/device_manager_if.go
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+Defines a DeviceManager Interface - Used for unit testing of the flow decomposer only at this
+time.
+*/
+package coreIf
+
+import "github.com/opencord/voltha-go/protos/voltha"
+
+// DeviceManager represents a generic device manager
+type DeviceManager interface {
+	GetDevice(string) (*voltha.Device, error)
+}