Mixed Integer Linear Programs for Blocking and No Wait Job Shop Scheduling Problems in Robotic cells

Abstract

This paper studies the problem of scheduling Job shops in robotic cells with no intermediate buffers, called No Wait Blocking Transport Job Shop Scheduling Problem (NWBT JSSP). This problem is an extension of the classical job shop problem. No Wait Blocking Transport job shop problems arise in many realistic production environments. To tackle this problem, we developed a Mixed Integer Linear Program and proposed a constructive heuristic based on priority rules. The MILP model has been used to solve optimally problems with as many as ten jobs, ten machines and three robots. Computational results on hypothetically generated test problems are discussed and suggestions of future research projects are proposed.