Design It!

Look for Classes of Functional Requirements

Functional requirements, often captured as use cases or user stories, define the software system’s behavior but are only sometimes interesting when designing the architecture. All functional requirements are essential to the success of the software system, but not all system features have architectural significance. When a functional requirement drives architectural decision making, we call it an influential functional requirement.

Influential functional requirements can be referred to as architecture killers. If your architecture doesn’t allow you to implement one of these high-value, high-priority features, you’ll be forced to raze your architecture and start over.

Identifying influential functional ...