Real time distributed shop floor scheduling using an agent-based service-oriented architecture

This paper proposes a distributed manufacturing scheduling framework at the shop floor level. The shop floor is modeled as a collection of multiple workcells. Each of which is modeled as a flexible manufacturing system. The framework consists of a distributed shop floor control structure, dynamic distributed scheduling algorithms, multi-agent system modeling of workcells, and service oriented integration of the shop floor. At the workcell level, a designated scheduler allocates jobs to resources and deals with any dynamic events locally, if possible. Otherwise, it collaborates with the other peer schedulers of workcells. Workcells are modeled as multi-agent systems. Local dynamic scheduling is achieved by the cooperation of the scheduler agent, the real time control agent and resource agents. Distributed scheduling is conducted through Web services facilitated by the service oriented shop floor integration. The proposed distributed control structure, dynamic distributed scheduling mechanisms and the system integration have been implemented using an agent-based service-oriented approach and validated through a case study.