Which phase focuses on defining the requirements for the architecture?

The phase that specifically focuses on defining the requirements for the architecture within the TOGAF framework is Phase B. This phase is known as the Business Architecture phase, where the primary aim is to ensure that the architecture aligns with the business goals and strategies. During Phase B, architects gather and assess the needs of stakeholders, define the business requirements, and create a vision for the business architecture. This involves establishing the necessary business processes, organizational roles, and information flows to meet those requirements.

In this context, the emphasis is on capturing and analyzing the business needs, which forms the foundation for all subsequent architecture development. By clarifying these requirements early in the architecture development process, Phase B helps ensure that the overall architecture is both relevant and effective in supporting the organization's strategic objectives. This makes it crucial for guiding later phases of architecture development.