Executable UML: A Foundation for Model-Driven Architecture

4.4. Formalizing Use Cases

The initial description of a use case is text. We can formalize the definition of a use case in terms of preconditions and postconditions. Preconditions state what must be true for the use case to execute. Postconditions state what must be true when the use case has completed.

The formulation of a use case in terms of pre- and postconditions is both precise and concise, in no way presupposes a particular design, and avoids the pitfall of specifying the use case in an overly procedural form.

4.4.1. Preconditions

Each use case may have zero or more preconditions.

Definition: A use case precondition denotes a relevant, verifiable property of the system that is required to be true before the use case is performed.

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