An extension of the use case diagram to model context-aware applications

Context-aware applications have the ability to sense the context of the user and use the sensed context information to make adaptation decision in response to changes in the user's context. Hence, besides the functional requirements, context-awareness is an important requirement of such applications. Although, the use case diagram of the Unified Modeling Language (UML) is considered as the industrial defacto standard for modeling the functional requirements of applications, it is insufficient to accurately capture context-awareness requirements. This paper proposes an extension of the use case diagram with new notations to cater for the modeling of context-aware applications. The proposed extension called context-aware use case diagram is more expressive and enables a clear separation of concerns between context-awareness requirements and functional requirements which is helpful during requirements capture and analysis of large scale or complex context-aware applications.