Practical experience of eliciting classes from use case descriptions

In moving from requirements analysis to design, use cases are often recommended as the starting point for the derivation of classes. However, exactly how classes are to be found within the use case is not entirely obvious. Typical approaches suggest a simple noun/verb search or brainstorming. Recent work is moving towards an interrogation of the use case diagram as a means of validation and of the description (and scenario) to elicit objects in the problem domain. This paper presents a set of Elicitation Questions that enables the interrogation of descriptions from the perspectives of specification, software architecture and design. This qualitative ‘interrogation’ teases out design issues. The Elicitation Questions were trialled through application to a real industrial project at a financial services company. Feedback from practitioners shows that the Elicitation Questions are important in raising design and testing issues from the use case descriptions but the organisational culture in how software is developed would impact its uptake.