Hybrid Flow-Shop Scheduling In Rubber Plant: A Case Study Of Long Thanh Loi Company.

Abstract

In this paper, a research project is discussed aiming to optimize the scheduling of production orders within a real application in the rubber field. As a first approach, it models the problem as an extended version of the hybrid and flexible flow shop scheduling problem with precedence constraints, parallel machines, and sequence-dependent setups. This study presents a mathematical model, four variants of iterated greedy algorithms and a variable block insertion heuristic for the Hybrid Flow-shop Scheduling Problem (HFSP) with makespan minimization. A detailed design of experiment is carried out to calibrate the parameters of the proposed algorithms. The developed model is solved for all instances on CPLEX under a time limit, and the performances of the proposed algorithms are assessed through comparisons with the results from CPLEX and the two best-performing algorithms in literature. Computational results show that the proposed algorithms are very effective in terms of solution time and quality. Additionally, the proposed algorithms are tested on large instances for the makespan criterion, which reveal that they also perform superbly for the makespan objective. Especially for instances with 20 jobs, the proposed algorithms are able to find the current incumbent makespan values reported in literature, and provide new best solutions