An improved genetic algorithm for job-shop scheduling problems using Taguchi-based crossover

A Taguchi-based genetic algorithm (TBGA) is proposed as an improved genetic algorithm to solve the job-shop scheduling problems (JSP). The TBGA combines the powerful global exploration capabilities of conventional genetic algorithm (GA) with the Taguchi method that exploits optimal offspring. The latter method is used as a new crossover and is incorporated in the crossover operation of a GA. The reasoning ability of the Taguchi-based crossover can systematically select the better genes to achieve crossover and, consequently, enhance the GA. Furthermore, mutation is designed to have the neighbor search technique of performing the fine-tuning on the positions of jobs for the JSP. Therefore, the proposed TBGA approach possesses the merits of global exploration and robustness. The proposed TBGA approach is effectively applied to solve the famous Fisher-Thompson and Lawrence benchmarks of the JSP. In these studied problems, there are numerous local optima so that these studied problems are challenging enough for evaluating the performances of any proposed evolutionary approaches. The computational experiments show that the proposed TBGA approach can obtain both better and more robust results than those evolutionary methods reported recently.