A partial modification method for disturbed production schedules by using hybrid genetic algorithm

Most of the existing studies about production scheduling aim to find an optimum production schedule before starting production activities. However, unpredictable disruptions may occur in the actual manufacturing environment. Therefore, the disturbed production schedule needs to be modified for the unpredictable disruptions. In our previous studies, a reactive scheduling method has been proposed by using a genetic algorithm in order to modify the disturbed production schedule without stopping production activities. However, the proposed scheduling method significantly changes the initial production schedule in the modification process of the production schedule in order to optimize the production schedule. The significant changes of production schedules may confuse the actual manufacturing environment. In this research, we propose a partial modification approach by extending the reactive scheduling method. A hybrid genetic algorithm is developed to improve the disturbed production schedule without greatly changing the initial production schedule. Computational experiments demonstrate that the new method is superior to the previous method.