In this paper, we present a framework called Web service based collaborative product commerce (WSCPC), which facilitates design and manufacturing process integration and coordination. In WSCPC, the design and manufacturing process is structured as a network of tasks. Companies can outsource a task, and join a process by providing their service. We propose an ontology based semantics using OWL-S to represent design and manufacturing activities as services. Manufacturing companies are able to publish their capabilities and identify potential manufacturing partners at the same time. We also present service models to support collaboration, which is based on Web ontology. Web ontology enables collaborative partners to understand each other's manufacturing decisions and behaviors, and hence help generate an optimal solution. We define interactions among companies during a process using a conversation model to support complex interactions necessary for flexible process management.