Appropriate content is achieved by looking at potential use cases from four different views.
Each view provides unique advantages. Together they offer the information needed to develop the fully elaborated use cases that facilitate clearly defined, understandable, measurable, and testable design. It is one of the most discussed and least well-implemented parts of the software engineering process. Interestingly, use case can be implemented without throwing away the value of the traditional shall statements and without tossing mission-based structured decomposition out the window. The primary goal of requirements definition should be the provision of value.