Scheduling the Supply Chain by Teams of Agents

When a supply chain is established supply chain management (SCM) needs supporting tools for the tasks of operative planning, scheduling, and coordination. These tasks have to be performed not only on the level of the enterprises involved but also within their established business entities (e.g. plants, areas, resource groups, resources) in which the high level schedules have to be put into operation. Most approaches of SCM favor a hierarchical coordination of the supply chain together with powerful algorithmic solutions for the mainly predictive scheduling tasks. These approaches are lacking the incorporation of feedback from lower levels and possibilities of reactive scheduling. Thus flexibility and reactivity are main issues to be improved. In this paper we will present an approach using teams of cooperating agents in a hierarchical as well as heterarchical way to overcome the problems mentioned. To simplify the generation of such a hierarchy of agents, we develop a framework for scheduling agents that contains the basic features of an agent e.g., event handling, data storage, communication, and possibilities for appending scheduling algorithms and specific cooperation mechanisms. The framework will be described and an example shall illustrate how it is used to build teams of cooperating agents on several levels of the scheduling hierarchy.