Dynamic scheduling of production-assembly networks in a distributed environment

In complex manufacturing environments, meeting the due dates of the jobs and minimizing in process inventories are important performance metrics. One of the common characteristics of complex production systems is production-assembly network of operations. This paper presents an auction-based algorithm for simultaneous scheduling of all manufactured and assembled jobs in a dynamic environment, where the objective function is to minimize both the due date penalties associated with the final products and the inventory cost of the work in process. An auction-based approach using a Mixed-Integer Linear Programming (MILP) model to construct and evaluate the bids so that the auction mechanism mimics a Lagrangian relaxation-based subgradient optimization to ensure global optimality is proposed. The inner structure of the problem enables very efficient calculation of bids for each job or assembly. Using a full factorial experimental design the properties of the proposed algorithm are analyzed. Results show that the proposed auction based algorithm performs better than the popular dispatching rules and is more scalable than the MILP model or direct implementations of the subgradient algorithm. Furthermore, the proposed algorithm is designed to work in a dynamic environment.