Recently, interests in the notion of process-oriented knowledge management (PKM) from academia and industry have been significantly increased. Comprehensive research and development requirements along with a cogent framework, however, have not been proposed for integrating knowledge management (KM) and business process management (BPM), which were proposed independently. Based on a comprehensive framework that reflects lifecycle requirements of both KM and BPM, this paper proposes an architecture for integrating knowledge management systems (KMSs) and business process management systems (BPMSs) to combine the advantages of the two paradigms. The paper first defines the concept of process knowledge and classifies it into three types. Then, it suggests how the functionalities of existing KMSs and BPMSs must be extended to support the three types of process knowledge while satisfying the lifecycle requirements of both knowledge and business processes. The architecture, which is comprehensive since it is derived from the extended requirements from the lifecycle perspective, will provide a basis for research and development of process-oriented knowledge management systems. A prototype system is presented to demonstrate the feasibility of the proposed architecture