A sequencing algorithm for mixed-model assembly lines

There exist many studies regarding sequencing problems in mixed-model assembly lines. The goal of many of these studies is to level the workload at each workstation on the assembly line in order to reduce the line stoppage time as much as possible. In the real mixed-model assembly lines of vehicles, the total workload of each vehicle is used to level the workload at each workstation. This is the same as the assembly lines having only one workstation. This is the reason why it is very difficult to maintain data on all the processing times of each workstation as listed in the following. (1) There exist many workstations in vehicle assembly lines. Moreover, the number of specifications for a vehicle is very large. (2) Continuous improvements for operations at workstations and assembly line balancing are always performed. As a result, we approach a sequencing problem for mixed-model assembly lines with only one workstation. There have been very few studies regarding this problem. Therefore, we have investigated it and obtained related characteristics. We propose an approximation algorithm using these properties. It is shown by numerical examples that the proposed algorithm can find a good sub-optimal solution.