Negotiation-based Manufacturing Control in Holonic Manufacturing Systems

The dream of holonic manufacturing is that fully operational Computer Integrated Manufacturing systems can be installed by merely plugging together manufacturing resources that are each controlled by an individual agent. The functionality of an holonic architecture would supersede and integrate the functionality currently in the islands of automation in Manufacturing Resource Planning (MRP II) systems, Distributed Control Systems (DCS), Manufacturing Execution Systems (MES) and Shop-Floor Control (SFC) systems, while providing additional benefit of fault tolerance, modularity, local empowerment, and overall flexibility. In a scenario, where order holons negotiate with resource holons to execute an operation, resource holons need to know about the market value of the capacity of their resource. We describe a new algorithm, called distributed probabilistic scheduling, that defines a probabilistic time window within which a resource holon can autonomously schedule an engagement. An engagement is used to express the likelihood that an operation is going to be executed on a certain resource. We propose the use of Bayesian Networks to encode this probabilistic model. This model provides an estimate of the predicted load over time for each resource. It also allows deferring resource allocation decisions until the last possible moment. The load estimate can help to optimize resource allocation decisions. The agents will continually update the probabilistic model based on these decisions.