Heuristic construction algorithm for the job shop problem with several robots and subject to blocking and no.-wait constraint

The work presented in this article focuses on the problem of job shop with different handling robots and subject to some constraints of blocking and no.-wait. The blocking constraint models the lack of storage capacity whereas the constraint of No.-wait appears when two consecutive operations should be performed without interruption. Jobs must be transported between machines by different handling robots. In this type of problem, deadlock situations where the system becomes paralyzed may appear. In this paper, we present a method based on graph theory which helps prevent the blocking states during schedule construction. The calculation of transportation operations starting times is also illustrated. Finally, we propose an algorithm for the construction of a heuristic based on priority rules to minimize the total execution time that is defined by the makespan.