Fast growth of foundry fabs, fierce global competition and advancements of information technology have motivated in the semiconductor industry the concept of Virtual Fab (VF) with emphasis on manufacturing service provisioning. In this paper, a conceptual framework is proposed for Ws, which consists of three layers: infrastructure, business process, and virtual product layers. Data warehouse, open real-time simulation service, dynamic binding and customer-oriented interface constitute the four key ingredients of the infrastructure Basic manufacturing business processes in the context of order management are then analyzed and manufacturing services are carefklly classified within the VF framework. How the proposed VF infrastructure facilitates these services and how service quality should be managed demand for hture research.