Dealing with NFRs for Smart-Phone Applications: A Goal-Oriented Approach

The utility of a smart-phone application depends not only on its functionality but also on its key non-functional requirements (NFRs), such as ubiquity, safety and usability. Omissions or commissions of considerations of such NFRs could lead to undesirable consequences, such as lack of user safety and difficulty in using smart-phone features. Currently, however, there is little systematic methodology for dealing with NFRs for a smart-phone application, in consideration of the particular characteristics of smart-phones, such as limited screen-size and battery-life, and the availability of a variety of embedded sensors and input/output devices. In this paper, we propose a goal-oriented approach in which NFRs are treated as softgoals, and then used in exploring, and selecting among, alternative means for satisficing them. In this approach, both synergistic and antagonistic interactions among the softgoals are identified and analyzed, considering the particular characteristics of smart-phones. As a proof of concept, a fall detection and response feature of a smart-phone application is presented, along with a safety scenario.