Advances in the Internet, communication technologies, and computation power have accelerated the cycle of new product development as well as supply chain efficiency in an unprecedented manner. Digital technology provides not only an important means for the optimization of production efficiency through simulations prior to the start of actual operations but also facilitates manufacturing process automation through efficient and effective automatic tracking of production data from the flow of materials, finished goods, and people, to the movement of equipment and assets in the value chain. There are two major applications of digital technology in manufacturing. The first deals with the modeling, simulation, and visualization of manufacturing systems and the second deals with the automatic acquisition, retrieval, and processing of manufacturing data used in the supply chain. This chapter summarizes the state of the art of digital manufacturing which is based on virtual manufacturing (VM) simulation and radio frequency identification (RFID)-based automation. The associated technologies, their key techniques, and current research work are highlighted. In addition, the social and technological obstacles to the development of a VM system and in an RFID-based manufacturing process automation system, and some practical application case studies of digital manufacturing based on VM and RFID-based automation, are also discussed.