1. A computer implemented method for extending a service model, the service model including specification of at least one exposed interface, wherein the exposed interface comprises a published interface defining at least the input parameters passed to the service, the output parameters from the service, the operations that can be called, and how to invoke these operations; the method comprising the steps of: receiving specification of information consumed by a service implementation of the service model, the information consumed comprising information that is accessed, updated, deleted and/or created by a service, the information being information that is or needs to be utilized by the service implementation without being passed through the exposed interface; and automatically generating an extended service model using a computer processor, the extended service model including specification of the exposed interface and specification of the information consumed by the service implementation; wherein the information consumed by the service implementation includes at least one of consumption type, non-functional annotation of the information consumed and specification of information sources; the non-functional annotation comprising a quality criterion for the information consumed by the service implementation, and the non-functional annotation also comprising a timing criterion for the information consumed specifying when the information consumed is required by the service implementation.