E-services are teams of applications and humans (participating electronically) that work together to provide a service or a product. Virtual Enterprises (VEs) are business or organizations that provide products or services that are created and managed by combining and wrapping e-services provided by multiple independent enterprises. To operate efficiently VEs must form supply chains that utilize and manage e-services. In this paper, we propose a Service Oriented Process model (SOP) and describe the architecture and the basic design principles of the Collaboration Management Infrastructure (CMI), a system that supports SOP. SOP permits modeling of e-services and provides for e-service integration to construct efficient multi-enterprise supply chains. This is accomplished by modeling composite e-services as Multi-Enterprise Processes (MEPs). In particular, SOP supports service activities for modeling the services themselves, primitives for composing supply chains from services, and primitives for automating service coordination as required by a supply chain. The CMI system implements SOP and uses a semantic broker that has knowledge about the service capabilities an quality. Therefore, a MEP (and hence its supply chain) is capable of on-the-fly choice of the service providers that are best suited to its objectives (e.g., cheapest or fastest).