Scheduling and balancing assembly lines with the task deterioration effect

Abstract Assembly lines are special flowline production systems that are of great importance in industrial mass production. This paper introduces task deterioration into the traditional simple assembly line balancing problem (SALBP). Task deterioration means that a task processed later consumes more time than the same task processed earlier. The aim is to find an optimal assignment and schedule of tasks at workstations so as to minimize the cycle time for a given number of stations, which in the literature is known as SALBP-2. For this purpose, a mathematical model is proposed. As SALBP-2 is classified as NP hard, and as the considered problem becomes more complicated with the additional deterioration parameter, a genetic algorithm is proposed. Finally, several well-known examples are solved to illustrate the approach proposed.