Agent-based workflow management for RFID-enabled real-time reconfigurable manufacturing

Recent developments in wireless technologies have created opportunities for developing reconfigurable wireless manufacturing systems with real-time traceability, visibility and interoperability in shop-floor planning, execution and control. This paper proposes to use agent-based workflow management as a mechanism to facilitate interactions among RFID-enabled reconfigurable manufacturing resources. A production process is modelled as a workflow network. Its nodes correspond to the work (process), and its edges to flows of control and data. Nodes are represented as agents and edges as messages. As a sandwich layer, agents wrap manufacturing services around a work-cell and their operational logics/intelligence for cost-effectively collecting and processing real-time manufacturing data, forming so-called work-cell gateways. A reference framework for a shop-floor gateway is proposed based on the three key components: Workflow management, manufacturing services universal description, discovery and integration (namely MS-UDDI) and work-cell agents. Work-cell agents are packaged, registered and published at MS-UDDI as web services which are easily reused and reconfigured in the workflow for a specific production process. Finally, a prototype system is presented to demonstrate how the proposed method is used to define and execute a real-time reconfigurable manufacturing project.