USE-CASE MODEL: WRITING
REQUIREMENTS IN CONTEXT
The indispensable first step to getting the things
you want out of life: decide what you want.
• Identify and write use cases.
• Relate use cases to user goals and elementary business processes.
• Use the brief, casual, and fully dressed formats, in an essential style.
• Relate use case work to iterative development.
This chapter is worth studying during a first read of the book because use cases
are a widely used mechanism to discover and record requirements (especially
functional); they influence many aspects of a project, including OOA/D. It is
worth both knowing about and creating use cases.
Writing use cases—stories of using a system—is an excellent technique to
understand and describe requirements. This chapter explores key use case con-
cepts and presents sample use cases for the NextGen application.
The UP defines the Use-Case Model within the Requirements discipline.
Essentially, this is the set of all use cases; it is a model of the system's function-
ality and environment.