Specifying Monitoring and Switching Problems in Context

Context-aware applications monitor changes in their operating environment and switch their behaviour to keep satisfying their requirements. Therefore, they must be equipped with the capability to detect variations in their operating context and to switch behaviour in response to such variations. However, specifying monitoring and switching in such applications can be difficult due to their dependence on varying contextual properties which need to be made explicit. In this paper, we present a problem- oriented approach to represent and reason about contextual variability and assess its impact on requirements; to elicit and specif' concerns facing monitors and switchers, such as initialisation and interference; and to specify monitoring and switching behaviours that can detect changes and adapt in response. We illustrate our approach by applying it to a published case study.