Goal-oriented Reasoning Techniques Study for Evaluating Alternatives in Requirement Engineering

摘要

In the field of Requirements Engineering, with the changes of organizational and technical situation for software, goal-oriented approaches have received much attention in recent years by researchers and practitioners alike. It is well known that exploring alternative options is at the heart of the requirements processes. But different alternatives contribute to different degrees of achievement of non-functional goals. As it often happens, non-functional goals do not need to be satisfied in an absolute sense. Most analysis techniques consider absolute goal satisfaction only; they do not support the evaluation of generated alternatives to guide the selection of most appropriate ones. Letier and van Lamsweerde present a model technique for specifying partial degrees of goal satisfaction and for quantifying the impact of different system alternatives on high-level goals that may be satisfied only partially. Within such model, non-functional goals are specified in a precise, probabilistic way; their specification is interpreted in terms of application-specific measures; impact of alternative goal refinements is evaluated in terms of refinement equations over random variables involved in the system's functional goals. Thus, it may then be used to guide requirements elaboration and design decision making.