Software Architect's Handbook

Primary functional requirements

Another important type of input into the architecture design is the primary functional requirements that need to be satisfied. Primary functional requirements are those that are critical to the organization's business goals. In Chapter 3, Understanding the Domain, we discussed core domains, which refer to the part of the domain that makes the software worth writing. Some of the primary functionality will come from the core domain. It is what differentiates the organization from competitors.

Although satisfying functional requirements is a goal of software architecture design, keep in mind that not all functionality is affected by the architecture. While some functionality is highly affected by the architecture, ...