Interfering Effects of Adaptation: Implications on Self-adapting Systems Architecture

When people are moving around using handheld networked devices, the environment for the provided services vary influencing service quality properties and user needs. In order to maintain usability and usefulness for mobile users, dynamic service adaptation is needed. Several forms of adaptation may be applied. For example, the application structure may adapt from thin client to self-reliant client, or network handover may be performed. The selection of an adaptation type is however far from obvious. Adaptation usually has impact on system resources or service quality. Also, one adaptation may require other adaptations that again have impact on resources and quality. This paper illustrates the complexity of selecting an adequate adaptation form. We argue that adaptation selection requires advanced reasoning and identify implications on the architecture of self-adapting systems.