Scenarios, Stories, Use Cases: Through the Systems Development Life-Cycle

CHAPTER 8

AUTHORING USE CASES

Camille Salinesi

Université Paris 1 Panthéon, Sorbonne, France

USE CASES are useful for representing a wide range of requirements, especially for nonspecialists. More than with any other kind of requirements, it is preferable to have well-written Use Cases (UC) rather than taking the risk of interfering with the rest of the software process with misinterpretations, missing information, inadequacy of content, and so on. But how do you write a good Use Case or scenario? This chapter puts together our experience in this domain with a set of guidelines that go beyond the simple templates that can be selected from tools and over the web.

APPLICABILITY

The proposed guidelines were developed in a tool named L'Ecritoire, which was implemented during the European-funded CREWS project on Co-operative Requirements Engineering With Scenarios. Theoretically grounded on a Fillmorian approach of natural language, they were empirically validated through a number of scientific experiments, and were used to good effect in projects with Europe-wide companies such as Alcatel, Eurocontrol, and Renault.

Experience shows that their main flaw is that they can hinder creativity when beginners try to apply them. However, once acquired by the authors, it is most often found that these guidelines may become extremely efficient. In particular, they reveal the importance of having an explicit view of the UC meta-model even when writing in natural language. Besides, they can easily ...