Identifying quality-requirement conflicts

One of the biggest risks in software requirements engineering is the risk of overemphasizing one quality attribute requirement (e.g., performance) at the expense of others at least as important (e.g., evolvability and portability). The paper describes an exploratory knowledge based tool for identifying potential conflicts among quality attributes early in the software/ system life cycle. The Quality Attribute Risk and Conflict Consultant (QARCC) examines the quality attribute tradeoffs involved in software architecture and process strategies. It operates in the context of the USC CSE WinWin system, a groupware support system for determining software and system requirements as negotiated win conditions. We have developed and experimented with an initial QARCC 1 prototype. We are using the results of the experiment to develop an improved QARCC 2 tool. From our initial experimentation, we concluded that QARCC can alert users, developers, customers, and other stakeholders to conflicts among their software quality requirements and can help them identify additional, potentially important quality requirements. We also concluded that QARCC needs further refinement to avoid overloading users with insignificant quality conflict suggestions. We are now refining the knowledge base to address more detailed quality attributes in a more selective fashion.