The joint line balancing and material supply problem

In production systems of automobile manufacturers multi-variant products are assembled on paced mixed-model assembly lines, which have to be supplied by a lean in-house logistic with containers of different sizes, alternative supply policies and different number of parts. The assignment of operations to workplaces within the assembly line balancing problem and the assignment of containers to supply policies within the material supply problem determine the operational cost of a work system. Up to now in the literature and real-world both problems are solved successively. We analyze the interdependence of the line balancing and material supply problem in depth and reveal potential productivity gains through simultaneous planning. We set up a practice-oriented assembly line balancing model, which is extended to cover several important logistical constraints of the material supply problem, and solved it with a flexible heuristic on the general assembly line balancing problem, we developed in an earlier paper. In a computational experiment, we determine cost savings through simultaneous planning and show the applicability of our approach within a practice-oriented experiment. & 2014 Elsevier B.V. All rights reserved.