In which ADM phase are the business principles, business goals and strategic drivers first validated?

The Preliminary Phase focuses on establishing the architecture capability and customizing the TOGAF framework, not specific project-level validation of business principles.

Phase A, the Architecture Vision phase, is where the initial architecture vision is created, encompassing the high-level business context including business principles, goals, and strategic drivers, and validating them to ensure alignment with the overall architecture work.

Phase B, Business Architecture, focuses on developing the baseline and target business architectures based on the vision established in Phase A.

Phase H, Architecture Change Management, deals with managing changes to the architecture after implementation.

Requirements Management Phase is an iterative process that manages requirements throughout the ADM, not a distinct phase for initial business context validation.