Users' needs are the driver of the next generationof telecom services. Founding the services on users' needsrequires that various services cooperate together to meetspecific needs. As a consequence, services should no morebe developed as "silo" but with composable serviceenablers. This enabler paradigm raises the issues of theidentification of the enablers and of the consistency of aservice composed from various enablers. These issues mustbe addressed by considering the service from the user pointof view: what is the added value for the user and throughwhich perceived steps is this added value provided? Suchservice business processes are then a key tool to identifyenablers and to ensure the coherence of composed service.