A hybrid metaheuristic based on the firefly and bat algorithms to solve the alternative subgraphs assembly line balancing problem

Assembly line balancing problem is the process of assigning a set of tasks to a group of stations, considering the precedence relations between tasks. Precedence relations are commonly definite; however, tasks may have alternative precedence relations due to different mounting alternatives. In the presence of alternative precedence relations, the classical balancing problem becomes more complicated given that two interdependent problems, namely selection and balancing, must be solved hierarchically. This type of balancing problem is named as the Alternative Subgraph Assembly Line Balancing Problem (ASALBP). This current paper concerns itself to develop an efficient solution procedure for the ASALBP by hybridizing the firefly and bat algorithms. The proposed hybrid algorithm is evaluated on a set of benchmark problems taken from the related literature and numerically compared against the standard firefly and bat algorithms, and some formerly developed heuristic methods. Computational results reveal the satisfactory performance of the proposed algorithm in solving ASALBP instances.