Two-sided assembly lines balancing with assignment restrictions

Two-sided assembly line is a set of sequential workstations where task operations can be performed in two sides of the line. The line is important for large-sized products, such as trucks, buses and cars. In this paper, we proposed a mathematical model for two-sided assembly line type II (TALBP-II) with assignment restrictions. The aim of the model is minimizing the cycle time for a given number of mated-workstations and balancing the workstation simultaneously. The model provides a more realistic situation of the two-sided assembly line problems. Genetic algorithm and iterative first-fit rule are used to solve the problem. The performances of both methods are compared using six numerical examples. Based on the experiments, the iterative first-fit rule can take the advantage of finding the best position over many workstations and the genetic algorithm provides more flexible task assignment and is significantly faster than the iterative first-fit rule.