Workload smoothing in simple assembly line balancing

•We consider Simple Assembly Lines with workload smoothing.•We aim to assign the tasks to the workstations so as to minimize the total squared workload.•We present a mathematical model and a branch and bound procedure.•Our computational study has revealed the satisfactory behavior of our mathematical model and branch and bound procedure.

This paper considers a simple assembly line balancing problem with fixed number of workstations and prespecified cycle time. Our objective is to minimize the sum of the squared deviations of the workstation loads around the cycle time, hence maintain workload smoothing. We develop several optimality properties and bounding mechanisms, and use them in our branch and bound algorithm. The results of our computational study reveal that our branch and bound algorithm is capable of solving medium sized problem instances in reasonable times.