The modern industry requires the next generation of manufacturing system to be intelligent, flexible, and interoperable. The manufacturing system also needs to offer better performance with lower cost. The huge success of cloud computing brings the opportunity to the manufacturing systems with high scalability, productivity and agility. It also provides practical solutions to the small and medium-sized enterprises with elastic investment solutions. In a cloud manufacturing system, the manufacturing resource and capability are provided in the service-oriented architecture as cloud services. In this research, the practical models of the cloud-based system are investigated, and distributed process planning services are developed accordingly. The proposed infrastructure is evaluated via a case study in which the industrial demonstrators are practised in the cloud as one specific type of process planning service.