Capturing, Organizing, and Reusing Knowledge of NFRs: An NFR Pattern Approach

Properly dealing with nonfunctional requirements (NFRs) such as security, cost, and usability, requires a large body of knowledge. However, it is difficult for average requirements engineers to possess necessary knowledge and use it correctly. This paper presents an NFR pattern framework for capturing NFR knowledge using goal, problem, causal attribution, solution/means, and requirements patterns that can be reused to help produce early-phase and late-phase NFR related requirements. The NFR patterns may be organized using generalization, aggregation, and classification relationships. Reusing the patterns is defined in terms of search and apply operations. The approach is illustrated using a running example based on the TJX incident, the largest credit card theft in history, to demonstrate how knowledge of the incident and mitigation techniques from security standards could be captured and used to help understand and prevent such incident.