The Service Portfolio represents all potential, current and expired services of the service provider.
It is a combination of the Service Pipeline and the service catagalog AND the retired services. Interestingly, the Service portfolio also includes third party services which may or may not be visible to the ultimate customer, but can be used as a contributor towards a customer service.
Service Portfolio Management (SPM) allows the best management of the available common pool of resources that are used to come up with the service concepts, the service design; then the service transition into operation of services.
Service Portfolio Management provides the necessary financial discipline to assess the viability of proposals and (for those that are viable the priority of investments against commitments).
This assessment results in a movement in the service porfolio (entry, progrss, exit) and the actual status given will be dependant on the funding and financial plan