A scatter search based hyper-heuristic for sequencing a mixed-model assembly line

In this paper a mixed-model assembly-line sequencing problem with the goal of minimizing work overload is addressed. We consider time windows in work stations of the assembly line (closed stations). Different versions of a product to be assembled in the line (e.g. automotive industry), which require different processing time according to the work required in each work station are considered. In a paced assembly line, products are feeded in the line at a predetermined constant rate (cycle time). Then, if many products with processing time greater than cycle time are feeded consecutively, work overload can be produced when the worker have insufficient time to finish its job. A scatter search based hyper-heuristic is proposed for this NP-hard problem. The procedure implies the use of priority rules. Computational results that show the efficiency of the hyperheuristic are presented.