The strength of goal models is their ability to assess candidate solutions against high level criteria for many stakeholders, allowing system-wide trade-offs to be performed. We argue that, in a context-aware system, reasoning based on goal models can complement standard rule-based reasoning engines for decision making without involving explicit interaction with the user. While rule-based systems excel in filtering out unsuitable solutions based on clear criteria, it is difficult to rank suitable solutions based on vague, qualitative criteria of stakeholders with a rule-based approach. The User Requirements Notation (URN) is a goal-based and scenario-based requirements modeling language that has been applied to many different domains, from reactive systems to telecommunication standards to business processes. For context-aware systems, URN's workflow notation can describe the overall behavior of a context-aware system and URN's goal models can further enhance reasoning about contextual situations. While URN already supports some of the interactions between workflow and goal models required for the specification of context-aware systems, it does not yet fully support the modeling, design-time simulation, and run-time execution of a context-aware system based on its URN model. This paper (i) introduces such a modeling, simulation, and execution environment, (ii) discusses three architectural solutions for combined rule-based and goal-oriented reasoning, and (iii) reports on a URN profile that describes a domain-specific language for context-aware reasoning using goal-orientation with the help of an example application from the health care domain.

Additional Metadata
Keywords context-aware systems, goals, requirements, rule-based reasoning, scenarios, user requirements notation, workflow
Persistent URL dx.doi.org/10.1145/2422518.2422520
Conference 7th Workshop on Models@run.time, MRT 2012 - Being Part of the ACM/IEEE 15th International Conference on Model Driven Engineering Languages and Systems, MODELS 2012
Citation
Vrbaski, M. (Mira), Mussbacher, G. (Gunter), Petriu, D, & Amyot, D. (Daniel). (2012). Goal models as run-time entities in context-aware systems. Presented at the 7th Workshop on Models@run.time, MRT 2012 - Being Part of the ACM/IEEE 15th International Conference on Model Driven Engineering Languages and Systems, MODELS 2012. doi:10.1145/2422518.2422520