Abstract
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.
Acknowledgements
The authors are most grateful to various companies who provide technical and financial supports to this research. The authors would like to acknowledge financial supports of HKSAR ITF (GHP/042/07LP) grant, HKSAR GRF (HKU/712508), National Science Foundation of China (50805116; 70629002), HKU Research Committee Grants, and from industrial collaborators.