Taking advantage of contextual information is very important for context aware applications especially in a mobile collaborative environment. This kind of applications adapt their behavior (self-adaptability property) according to the user needs, the available resources and the surrounding environment. This property is enforced by four phases; monitoring the application and its environment, analyzing context changes, planning adaptation actions and executing the planned actions to respond to context changes. In this paper, we focus and discuss the second phase. First, we propose a novel context classification which covers almost all of the context aspects. Then, we propose an analysis approach for collaborative ubiquitous systems. Our approach relies on different kinds of thresholds. Once relevant context changes occur, the context aware application will be notified to trigger its suitable process dynamically in order to deal with the changes.
