A note on 'Workload smoothing in simple assembly line balancing'

摘要

Workload smoothing is a variant of the well-known simple assembly line balancing problem. Given the number of (work) stations and the cycle time, the objective is to minimize the sum of squared workloads. Recently, Azizoglu and Imat [Computers & Operations Research 89 (2018) 51-57] have proposed an exact branch-and-bound algorithm to solve this problem. However, we reveal that one of the lower bounding procedures used within their algorithm is incorrect. By means of an example, we demonstrate that the wrong bound can prevent their branch-and-bound algorithm from finding optimal solutions. We correct the bounding argument and also provide a tighter formulation. (C) 2019 Elsevier Ltd. All rights reserved.