Change window

- is it Change implementation + Back Out + Validation and Testing
- or Pre Implementation + change Implementation + Back Out + validation testing
- or change Planning + pre Implementation + change Implementation + Back Out + validation testing

The answer:
Change window is agreed time when changes i.e. releases may be implemented. Guiding idea is to make minimal impact on services i.e. that's how change window should be planned. This means that change window will encompass change implementation. Back-out procedure should be in scope of change window in a way that you define threshold until you invoke back-out procedure. For example, if your change window is 4 hours, you can define that back-out procedure will be activated after 3 hours have passed. Of course, if 1 hour is enough for back-out procedure.
Following articles will give good overview of Change Management:
- How to measure Change Management efficiency according to ITIL https://advisera.com/20000academy/blog/2016/10/11/how-to-measure-change-mana gement-efficiency-according-to-itil/
- ITIL V3 Change Management – at the heart of Service Management https://advisera.com/20000academy/knowledgebase/itil-v3-change-management-at-the-heart-of-service-management/
- Elements of Change Management in ITIL https://advisera.com/20000academy/blog/2013/04/23/elements-change-management-itil/