Does anyone have a good base template that can assist with transition to Operations after the project completion?

I have, but they vary significantly depending on many factors such as the system being transitioned, the level of criticality, and the delivery approach. For example if you're phasing in software incrementally, you have more opportunity for post-implementation changes than if you're launching a satellite into orbit. For a more detailed explanation, I would suggest searching the SEBoK (Systems Engineering Body of Konwledge).