The figure describes the various processes a service goes through, from the analysis of the subscriber's requirements to the service to the deinstallation of it. After analysis, the service is specified, designed, implemented and installed. After activation the service can be invoked an arbitrary number of times (including none), each invocation to be followed by the execution of the service. At some time, the service is deactivated, and eventually deinstalled. Arrows between two processes depict that the service can go from the first process to the second.