In the past there was the RunSAP implementation methodology. This is now succeeded with the SAP Activate methodology. The most important one is the S4HANA implementation.
You can go to the methodology using this link.
The roadmap now opens:
The methodology is split into several phases:
The method is focusing more on using out-of-the-box SAP software and focused on Agile/Scrum way of implementing S4HANA.
On the tab content you can find useful content per phase:
And accelerators per phase:
Keep in mind the method is focusing on green field implementation. Nevertheless you can still use the content and accelerators in your own projects.