| With much change of the market and the diversification of customer need, variety and small batch production mode has become the main way of manufacturing gradually. The study of optimization method for batch scheduling is very important to modernization of advanced manufacturing because of its theoretical and practical significance.The conception, development and the main researches in current and in the future of job shop scheduling are introduced; some research methods are introduced and compared. Basic foundation, process and operations of GA are stated briefly, and the characteristics and theoretic are discussed.The job shop scheduling problem with alternative machine is investigated and its scheduling integration diagram is established. Based on genetic algorithms, a new scheduling algorithm with multiple process plans and no set up time is proposed, and the algorithm is compared with another scheduling algorithm proposed by Nasr and Elsayed. The results show that the proposed algorithm is correct and excellent. Then, considering the practical production, machining time and set up time are detached, a novel scheduling algorithm with multiple process plans and set up time is addressed, and the result shows the proposed algorithm is well which is compared with no set time scheduling algorithm.The job shop scheduling problem with alternative machine in the batch process is studied and its mathematics model is established. To reduce the makespan of variety and small batch job shop scheduling problem, a new approach using double Genetic Algorithms is proposed,and based on processing sequence of sub-lots, a novel encoding scheme for the variable chromosome length of lot splitting scheduling is presented. Theoretically, the best optimization solution of overall situation can be achieved from the proposed algorithms. Finally, an example of scheduling is given, three scheduling strategies are studied and the results show that the method can acquire good performance of scheduling.
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