Reasoning about Contextual Requirements for Mobile Information Systems: a Goal-based Approach

Mobile information systems are characterized by their ability to adapt to varying contexts. There is a strong relationship between the requirements of a mobile information system and its operational context. On the one hand, context can be considered to determine the requirements, the alternatives that can be adopted to satisfy these requirements, and qualities of the systems. On the other hand, the system itself may cause changes in the context during its operational activities. More fundamentally, context influences users' goals and the way they achieve these goals. In previous work, we introduced contextual goal modeling, a systematic way to analyze and specify contexts. The key idea was to associate variants for goal satisfaction with contexts. In this paper, we propose analysis techniques and automated reasoning mechanisms to verify properties of contextual goal models. We show how to detect inconsistent context specifications and how to analyze possible runtime conflicts originated by context changes. Also, we present an analysis process to construct and reason about contextual goal models. We illustrate and evaluate our framework through a case study of a mobile information system for supporting the life of people with dementia.