Web Services provide our systems with a platform independent and loosely coupled distributed computing environment. However, on adding extra-functional properties to web services, the loosely coupled environment is not always maintained due to dependences established between the main functionality service modules and the ones from added properties, thus decreasing the application?s modularity and flexibility. In order to decouple extra-functional properties from services at modeling and implementation stage, we propose to use a model driven approach, in which the Platform Independent Model (PIM) has been designed by using UML. Then, ATL transformation rules have been applied to transform the PIM into the Platform Specific Model (PSM), which has been split into three specific models, an object, an aspect and a policy based models. Finally Java, AspectJ and Ws-Policy code is generated from the specific models.