Use Cases versus Task Descriptions

摘要

[Context and motivation] Use cases are widely used as a substantial part of requirements, also when little programming is expected (COTS-based systems). [Question/problem] Are use cases effective as requirements? To answer this question, we invited professionals and researchers to specify requirements for the same project: Acquire a new system to support a hotline. [Principal ideas/results] Among the 15 replies, eight used traditional use cases that specified a dialog between users and system. Seven used a related technique, task description, which specified the customer's needs without specifying a dialog. [Contribution] It turned out that the traditional use cases covered the customer's needs poorly in areas where improvement was important but difficult. Use cases also restricted the solution space severely. Tasks didn't have these problems and allowed an easy comparison of solutions.