Heuristic procedure for the assembly line balancing problem with postural load smoothness

This paper presents a heuristic procedure for assigning assembly tasks to workstations where both productivity and ergonomics issues are considered concurrently. The procedure uses Kilbridge and Wester's algorithm to obtain an initial task-workstation assignment solution which minimizes the balance delay of an assembly line. A task reassignment algorithm was applied to improve the initial solution by exchanging assembly tasks, which smooth postural load among workers, between workstations. A composite index of variation was used to measure the effectiveness of the task-workstation assignment solution. On the basis of clothes assembling, it was found that the task-workstation assignment solution with a minimum composite index of variation can be obtained with relatively equal weights in balance delay and postural load.