Optimizing work-sharing assignments for replacements of absentees in assembly lines

This paper analyzes the throughput of short bottle neck segments caused by inexperienced workers replacing absentees. By definition, a bottleneck in an assembly line determines the throughput of the whole line. Therefore, under the assumption that the analyzed segment is indeed the bottle neck, the segment analysis is equivalent to measuring throughput of a complete assembly line. The analyzed bottleneck segment is a set of three consecutive workstations, consisting of the inexperienced worker replacing the absentee, and the upstream and downstream experienced workers assisting the new worker during the learning period. Using an analytic description and a numerical example it is clearly shown that work sharing can significantly improve the line's throughput. The decision variables of this model are: (1) the amount of shared work, and (2) the timing of the shared work transfer back to the substitute worker. We show how to optimize this combination of variables using a numerical analysis.