Networks are evolving from circuit-switched to packet-switched based architectures.During the transition period, services will have to be provided to both types of networks. A Services Delivery Platform (SDP) is needed to design, create, deploy and manage the services that will be executed on these networks. This report describes the characteristics of such a Service Delivery Platform for complex services. Also presented is a perspective of the importance of SDP as an enabler of partnered business models, centerpiece to Operator business model transformation, and interface to a better user experience.