Flexible Job Shop Scheduling Optimization Algorithm

Due to machine constraint, flexible job shop scheduling is much more complex than traditional job shop scheduling.Thus, seeking the effective methods used to solve flexible job shop scheduling has important theoretical and applied significance. In this paper, genetic algorithms and particle swarm optimization are studied in flexible job shop scheduling , the main work and innovations are as follows :(1) This paper studies the single objective flexible job shop scheduling problem in genetic algorithm. First, we introduce the virus mechanisms. Through the virus groups infect the main groups the diversity of the main groups and the algorithm capacity of local search are increased.Experiments proved that genetic algorithms based on the virus mechanisms overcome the prematurity and slow convergence disadvantages of traditional genetic algorithm in flexible job shop scheduling problem. Then, we propose a self-adaptive genetic algorithm based on the characteristic of flexible job shop scheduling and the history of genetic search. Through evaluation function .we adjust crossover and mutations' probability self-adaptive in order to improve search efficiency and stability of the algorithm.(2) This paper studies the multi-objective flexible job shop scheduling problem in genetic algorithm.First, we adopt uniform design techniques to compose a number of fitness functions.The genetic algorithm based on uniform design techniques improves the equality of search space.Then, we compute the crowding distance of individuals based on the Pareto optimal concept for the second rank. The genetic algorithm based on two ranks alleviate the trend that the populations converge to a single solution over the course of the genetic search process and avoid losing solutions because of traditional genetic algorithm's prematurity.(3) This paper studies the multi-objective flexible job shop scheduling problem in particle swarm optimization.First, we construct the particle presentation for flexible job shop scheduling according to the characteristic...