A specification pattern for use cases

In this paper, general formats and guidelines are proposed, in an attempt to ameliorate the impact of frequently observed difficulties during the specification of use cases generated using “natural language” for the documentation of system functionality. The various writing styles derived from the multiple grammatical alternatives found in the Spanish language and the terminological diversity that characterises this language tend to reduce the clarity of text in a use-case specification. Thus, the purpose of its use in the different stages of development in a software system or component is seriously affected. However, even if this study has been made specifically for the Spanish language, it could be easily generalised to any language whose sentences are of the form subject/predicate. In order to control these problems, the use of a specification pattern supported by a series of guidelines on style and terminology is proposed for drafting use cases. Additionally, various degrees of refinement are suggested to guide specifiers towards obtaining a use case written according to this pattern.