A dynamic scheme for scheduling complex tasks in manufacturing systems based on collaboration of agents

The characteristics of scheduling tasks in the real world is a dynamic and challenging issue as the processes and the companies involved may change from time to time. For small flexible enterprises to respond to business opportunities, an effective scheme to facilitate dynamic coalition, share the core competencies and resources and support inter-enterprise collaboration must be developed. Although multi-agent systems (MAS) provide a paradigm for modeling these characteristics, scheduling tasks in MAS is a complex problem due to the computational complexity involved, distributed architecture for scheduling tasks by individual agents and dependency of different agents’ workflows. How to develop a problem solver that can be applied in MAS to achieve coherent and consistent workflow schedules that can meet a customer’s order is an important issue. In this paper, we propose a solution methodology for scheduling workflows in MAS. Our solution combines the multi-agent system architecture to dynamically discover services, workflow and activity models to specify the capabilities of agents, contract net protocol to facilitate negotiation and coordination of agents and optimization theories to optimize the cost for fulfilling an order. A problem solver for scheduling tasks in MAS has been implemented. An application scenario has also been provided to verify our solution methodology.