Aspect-oriented executable UML models for context-aware pervasive applications

Pervasive applications must be aware of the contexts where they are executed. These contexts may vary greatly from each other and may change quickly. Thus, pervasive applications should be highly, reconfigurable in order to deal with such context changes. There are two main problems associated with this issue: (1) context-awareness is a crosscutting concern that can not be well-encapsulated in a single module using traditional technologies, which hinders application design maintenance and reusability; and (2) reasoning about application design correctness can be complex due to the number and diversity of potential contexts where a pervasive application could be executed. In order to overcome these problems we propose the use of the Aspect-Oriented Executable Modelling (AOEM) UML 2.0 Profile for designing pervasive applications. Aspect-Oriented techniques contribute to the encapsulation of crosscutting concerns, such as context-awareness, into well-localized modules. Executable Modelling helps engineers to reason about application design by executing the design models in different contexts and situations. Finally, we will discuss how these aspect-oriented models would map into a middleware platform that provides built-in services to support pervasive applications. Services, such as context-awareness, are provided as a set of user-configurable aspects. These ideas are illustrated using a location-aware intelligent transportation system consisting of a set of cooperating sentient vehicles.