CMU / SEI-92-TR-0 12 ESC-TR-92-012 Issues in Requirements Elicitation

There are many problems associated with requirements engineering, including problems in defining the system scope, problems in fostering understanding among the different communities affected by the development of a given system, and problems in dealing with the volatile nature of requirements. These problems may lead to poor requirements and the cancellation of system development, or else the development of a system that is later judged unsatisfactory or unacceptable, has high maintenance costs, or undergoes frequent changes. By improving requirements elicitation, the requirements engineering process can be improved, resulting in enhanced system requirements and potentially a much better system. Requirements engineering can be decomposed into the activities of requirements elicitation, specification, and validation. Most of the requirements techniques and tools today focus on specification, i.e., the representation of the requirements. This report concentrates instead on elicitation concerns, those problems with requirements engineering that are not adequately addressed by specification techniques. An elicitation methodology is proposed to handle these concerns. This new elicitation methodology strives to incorporate the advantages of existing elicitation techniques while comprehensively addressing the activities performed during requirements elicitation. These activities include fact-finding, requirements gathering, evaluation and rationalization, prioritization, and integration. Taken by themselves, existing elicitation techniques are lacking in one or more of these areas.