Applying Line Balancing to Improve Production Line Efficiency: A Case Study of an Automotive Company

Abstract

This research aims to improve the efficiency of an automotive engine production line by reducing waiting waste caused by an unbalanced workload. Currently, there are 94 tasks allocated to 8 workstations. The cycle time of the bottleneck workstation, which is 167.60 seconds per unit, is higher than the takt time set at 87 seconds per unit. The tasks in the production line have been divided into 3 groups due to limitations in space and machinery. The tasks in each group will be balanced separately. The tasks in groups 1 and 3 can be arranged on the workstations to achieve a cycle time lower than the takt time, with the same number of workstations. To balance the assembly line in these groups, a mathematical model is used with the objective of minimizing cycle time under the constraint of a fixed number of workstations and a cycle time not exceeding the takt time. However, the other group does not consider the constraint of a cycle time lower than the takt time because the company does not want to increase the number of existing workstations, which is currently insufficient to meet this constraint. The Branch and Cut algorithm using the COIN-OR CBC library in OpenSolver is used to solve the mathematical models. The experimental results show that the production line balancing efficiency has improved for all groups, with an increase from 70.35% to 96.56% for group 1, an increase from 81.52% to 99.91% for group 2, and an increase from 90.42% to 98.92% for group 3. The lead time is reduced from 235.18 minutes to 198.51 minutes.