Many software applications are now built from services which run on heterogeneous platforms and are accessed by several users. These environments are in constant evolution. So applications and services have to dynamically adapt in order to satisfy the quality of service required by the users. Programming adaptation facilities taking into account the different situations that could happen is a difficult task. Our objective is to provide mechanisms for self-adaptation of services. We propose a generic framework that allows to specify different kinds of adaptation, in various environments. This paper presents the overall framework and details some of its functionalities: the monitoring, the decision to adapt and the planning of adaptation actions. The current state of our implementation for an OSGi platform is described.