diff --git a/ro_core/core/device_manager_test.go b/ro_core/core/device_manager_test.go
new file mode 100644
index 0000000..bb2a1bc
--- /dev/null
+++ b/ro_core/core/device_manager_test.go
@@ -0,0 +1,185 @@
+/*
+ * Copyright 2019-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.
+ */
+package core
+
+import (
+	"github.com/opencord/voltha-go/ro_core/config"
+	"github.com/opencord/voltha-lib-go/v2/pkg/db/model"
+	"github.com/opencord/voltha-protos/go/voltha"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func MakeTestDevManagerConfig() (*Core, error) {
+	var core Core
+	core.instanceId = "ro_core"
+	core.config = config.NewROCoreFlags()
+	backend := model.Backend{
+		Client:     core.kvClient,
+		StoreType:  core.config.KVStoreType,
+		Host:       core.config.KVStoreHost,
+		Port:       core.config.KVStorePort,
+		Timeout:    core.config.KVStoreTimeout,
+		PathPrefix: "service/voltha"}
+	core.clusterDataRoot = model.NewRoot(&voltha.Voltha{}, &backend)
+	core.genericMgr = newModelProxyManager(core.clusterDataProxy)
+
+	return &core, nil
+}
+func TestNewDeviceManager(t *testing.T) {
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+}
+
+func TestListDeviceIds(t *testing.T) {
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	myIds, _ := core.deviceMgr.ListDeviceIds()
+	assert.NotNil(t, myIds)
+}
+
+func TestGetDeviceAgent(t *testing.T) {
+
+	// Tests also methods addDeviceAgentToMap,
+	//                    listDeviceIdsFromMap
+	//                    deleteDeviceAgentToMap
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	devAgent := newDeviceAgent(&voltha.Device{Id: "new_device"}, core.deviceMgr, core.clusterDataProxy)
+	assert.NotNil(t, devAgent)
+
+	// addDeviceAgentToMap
+	core.deviceMgr.addDeviceAgentToMap(devAgent)
+
+	// listDeviceIdsFromMap
+	myIDs := core.deviceMgr.listDeviceIdsFromMap()
+	assert.NotNil(t, myIDs)
+
+	// getDeviceAgent
+	myDevAgent := core.deviceMgr.getDeviceAgent(devAgent.deviceId)
+	assert.NotNil(t, myDevAgent)
+
+	// deleteDeviceAgentToMap
+	core.deviceMgr.deleteDeviceAgentToMap(devAgent)
+}
+
+func TestLoadDevice(t *testing.T) {
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	devAgent := newDeviceAgent(&voltha.Device{Id: "new_device"}, core.deviceMgr, core.clusterDataProxy)
+	assert.NotNil(t, devAgent)
+
+	// addDeviceAgentToMap
+	core.deviceMgr.addDeviceAgentToMap(devAgent)
+
+	myDev, err := core.deviceMgr.loadDevice("new_device")
+	assert.NotNil(t, myDev)
+	assert.Nil(t, err)
+}
+
+func TestIsDeviceInCache(t *testing.T) {
+
+	// Tests also methods addDeviceAgentToMap,
+	//                    listDeviceIdsFromMap
+	//                    deleteDeviceAgentToMap
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	devAgent := newDeviceAgent(&voltha.Device{Id: "new_device"}, core.deviceMgr, core.clusterDataProxy)
+	assert.NotNil(t, devAgent)
+
+	// addDeviceAgentToMap
+	core.deviceMgr.addDeviceAgentToMap(devAgent)
+
+	isInCache := core.deviceMgr.IsDeviceInCache(devAgent.deviceId)
+	assert.True(t, isInCache)
+
+	// deleteDeviceAgentToMap
+	core.deviceMgr.deleteDeviceAgentToMap(devAgent)
+
+	isInCacheDel := core.deviceMgr.IsDeviceInCache(devAgent.deviceId)
+	assert.False(t, isInCacheDel)
+}
+
+func TestLoadRootDeviceParentAndChildren(t *testing.T) {
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	devAgent := newDeviceAgent(&voltha.Device{Id: "new_device"}, core.deviceMgr, core.clusterDataProxy)
+	assert.NotNil(t, devAgent)
+
+	// addDeviceAgentToMap
+	core.deviceMgr.addDeviceAgentToMap(devAgent)
+
+	err := core.deviceMgr.loadRootDeviceParentAndChildren(devAgent.lastData)
+	assert.Nil(t, err)
+}
+
+func TestGetParentDevice(t *testing.T) {
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	devAgent := newDeviceAgent(&voltha.Device{Id: "new_device"}, core.deviceMgr, core.clusterDataProxy)
+	assert.NotNil(t, devAgent)
+
+	// addDeviceAgentToMap
+	core.deviceMgr.addDeviceAgentToMap(devAgent)
+
+	myDev := core.deviceMgr.getParentDevice(devAgent.lastData)
+	assert.Nil(t, myDev)
+}
+
+func TestGetAllChildDeviceIds(t *testing.T) {
+
+	core, _ := MakeTestDevManagerConfig()
+
+	core.deviceMgr = newDeviceManager(core.clusterDataProxy, core.instanceId)
+	assert.NotNil(t, core.deviceMgr)
+
+	devAgent := newDeviceAgent(&voltha.Device{Id: "new_device"}, core.deviceMgr, core.clusterDataProxy)
+	assert.NotNil(t, devAgent)
+
+	// addDeviceAgentToMap
+	core.deviceMgr.addDeviceAgentToMap(devAgent)
+
+	myIds, err := core.deviceMgr.getAllChildDeviceIds(devAgent.lastData)
+	assert.NotNil(t, myIds)
+	assert.Nil(t, err)
+}