Integrated consideration of assembly line scheduling and feeding : a new model and case study from the automotive industry

Kurzfassung/Abstract

Line feeding policy decision models decide upon whether a warehouse part is supplied by line stocking, kitting or sequencing. Although the production schedule determines the point of use and the usage rates of parts at the assembly line, no line feeding model till date integrates the operational production schedule decision into the tactical line feeding decision. Therefore, we introduce a new mixed-integer linear programming formulation that models the interactions between both planning problems explicitly. The developed model is applied in a real-life case study of a mixed-model assembly line from a first-tier automotive supplier. The numerical results show that both the cost-optimal line feeding policy decision as well as the resulting costs depend on the production schedule with the inherent degree of grouping equal jobs and the product mix. Depending on the product mix, following a leveled scheduling approach instead of a grouping of equal jobs can increase line feeding costs by up to 18%. Thus, the scheduling decision has to become a crucial element of future line feeding models for mixed-model lines.