Multi-degree cyclic flow shop robotic cell scheduling problem: ant colony optimization

This paper deals with the multi-degree cyclic robotic flow shop cell scheduling problem with multiple robots. All the parts are processed successively through the machines with standard processing times while single gripper robots perform the transportation operations of parts between the machines. Due to the special characteristics of the considered problem, a metaheuristic algorithm based on ant colony optimization has been proposed. The proposed algorithm simultaneously determines the optimal degree of the cyclic schedule, the robot assignments for the transportation operations, and the optimal sequence of robots' moves, which in return maximize the throughput rate. The efficiency of the proposed metaheuristic algorithm is examined by a computational study on a set of randomly generated problem instances.