Parallel machines scheduling with uncertain processing time based on rough programming

Considering the uncertain processing time in scheduling problems,rough variables are employed to address it and a rough expected value model for parallel machines scheduling is presented.In addition,an improved evolutionary programming algorithm for scheduling problems is proposed by redefining representation structure of individuals and mutation operator.To evaluate the fitness of individuals,rough simulation is adopted to calculate the expected values of objectives.Computational results of different scales of problems show that the rough simulation based evolutionary programming algorithm is efficient.