There is an increasing demand from firms to evolve their applications to be more co-operative. The problem is to realise this migration and to maintain the quality of existing applications which are reliable due to previously encountered difficulties. We will propose a method based on an organisation of dynamic workgroups (their composition can evolve with time) composed of components. Thus method is entirely derivable (after a formal verification) into rules integrated into a cooperative architecture allowing the cooperation. In order to propose an operational method, the last stage will propose to obtain rules derived from a specification language associated to the method. Our approach allows the provision of cooperation thanks to the application re-engineering without modifying any existing component.