Tuesday, November 23, 2004
Generating Complete, Unambiguous, and Verifiable Requirements from Stories, Scenarios, and Use Cases "Although very valuable as requirements elicitation, analysis, and initial validation tools, stories, scenarios, and use case path specifications are typically inadequate for specifying requirements because they are incomplete, ambiguous, and therefore unverifiable. For example, they usually do not address preconditions and postconditions, which have a huge influence on the meaning of the requirements. Similarly, they do not tend to state the triggering events that cause them to be true. They also do not typically clarify the distinctions between requirements (i.e., what the system must do and what postconditions it must ensure) and ancillary information (e.g., triggering events produced by actors and preconditions that may or may not be ensured). This column has provided examples and guidance on how to transform stories, scenarios, and use case path specifications into complete, unambiguous, and verifiable textual requirements."