Master production scheduling and sequencing at mixed-model assembly lines in the automotive industry

The customization of final products in the automotive industry involves a large number of optional parts and leads to a huge variety of operation times at the various stations of the assembly line. The master production scheduling problem (MPS) for high-variant mixed-model assembly lines is to assign the individual customer-defined models of a basic product type to short-term production periods while anticipating the negative impacts of an unbalanced model sequence at the lower planning level. We propose a mathematical model formulation for the MPS and develop heuristic solution procedures that attempt to minimize the workload variability. Specifically, these procedures anticipate decisions on the mixed-model sequence and the resulting work overload at stations which has to be balanced by the assignment of utility workers. Furthermore, an integrated planning approach for solving the MPS and the production sequencing problem is proposed.