Pattern 15.7 Construct a System Behavior Spec

Cast System Requirements in Terms of the Business Model See Pattern 15.7, Construct a System Behavior Spec. Particularly if the domain model has been clearly defined, system requirements can be discussed, understood, and decided far more precisely. 

Pattern 15.7, Construct a System Behavior Spec Treating your system as a single object, create a type specification for any system that would meet the requirements. Actions (and hence the type model) should be as abstract as possible at first cut—not individual keystrokes ... 

A component specification has been written. It may come from requirements analysis (see Pattern 15.7, Construct a System Behavior Spec) or may be a part of the design of something larger (see Pattern 16.3, Reifying Major Concurrent Use Cases). 

---