Paper Title
INTEGRATED SCHEDULING OF FLEXIBLE JOB SHOP AND ROBOT ROUTES WITH SPEED OPTIMIZATION

Abstract
In smart manufacturing environments, the transportation of workpieces between machines is facilitated by autonomous mobile robots. This study considers a flexible job shop in which machines operate without buffersand workpiece transportation is carried out by a limited number of robots with adjustable traveling speed.The absence of buffers can lead to a workpiece being blocked on its processing machine after completing operations, waiting for an available robot to pick it up. By adjusting the robot’s speed, waiting times can be significantly shortened, thereby enhancing the overall efficiency of the production system.On the other hand, if the robot moves too quickly, it may wait in front of a machine for the completion of an operation.Therefore, the problem under investigation involves determining the machine from a set of alternatives to process each operation of each job,establishing the processing sequences of operations on machines, planning the robot routes for transporting workpieces, and finding the optimal speed forrobots, while avoiding deadlocks in the integrated system. The problem is formulated as a mixed-integer linear programming model that minimizes the exit time, i.e., the time for all completed workpieces to return to the unloaded area, and thetotal waiting time required by the robots.A customized Benders decomposition approach is developed to solve the proposed model, and computational experiments are conducted to evaluate the advantages of incorporating adjustable robot speed. Keywords - Flexible Job Shop Scheduling; Autonomous Mobile Robots; Production Scheduling; Mixed-Integer Linear Programming; Speed Control