The document proposes a Service Portfolio Model (SPM) for managing value co-creation in knowledge-intensive service systems. The SPM classifies services into basic, flexible, and custom categories based on the level of participation from external service systems in knowledge asset development. It presents SPM as the starting point for a dynamic service management framework comprising different value co-creation paths. Future work includes fully developing the value co-creation paths and performance measurement framework and further deploying the approach within a collaboration knowledge service system.