As Grid architectures provide resources that uctuate, applications that should be run on such environments must be able to take into account the changes that may occur. This document describes how applications can be built from components that may dynamically adapt themselves. We propose a generic framework to help the developpers of such components. In the case of a component that encapsulates a parallel code, a consistency model for the dynamic adaptation is dened. An implementation of a restricted consistency model allowed us to experiment our ideas.