Which architecture domain is the first architecture activity undertaken in the ADM cycle?

The Business Architecture domain is the first architecture activity undertaken in the Architecture Development Method (ADM) cycle. This is because the ADM begins with a clear understanding of the business context and objectives, which is essential for guiding the development of the subsequent architecture domains.

Understanding the Business Architecture sets the foundation for all other architectural decisions, helping to align IT strategies with business goals. It involves defining the business strategy, governance, organization, and key business processes, which are critical for ensuring that the architecture effectively meets the needs of the organization.

By starting with Business Architecture, organizations can ensure that the subsequent domains — Application, Data, and Technology — are developed with a solid understanding of the organizational requirements and challenges, thereby enhancing the effectiveness of the overall architecture solution.