Research On The Key Problems Of Multi-objective Production Scheduling Based On Uncertain Process Time

In recent years,with the rapid development of manufacturing industry in our country,it has become an inevitable trend to solve the production scheduling problem using intelligent and information technology.Based on flexible job shop scheduling problem and mixed-model assembly line sequenencing problem,this paper takes uncertain process time and machine preventive maintenance into consideration,and studies the optimization problem of multi-objective production scheduling by using intelligent optimization method.Firstly,in order to solve the multi-objective fuzzy flexible job shop scheduling problem,we have designed three objective functions that include the maximum fuzzy completion time(fuzzy makespan),the maximum fuzzy workload and the weighted agreement index.The three objectives are optimized simultaneously by the modified artificial bee colony algorithm(MABC).The validity of the improved algorithm is verified by solving benchmark instances,and the sensitivity of the algorithm’s control parameters is analyzed.Secondly,we have researched the multi-objective fuzzy flexible job shop scheduling problem based on the machine preventive maintenance.The optimization goal is average fuzzy completion time,bottleneck machine fuzzy workload,total machine fuzzy workload and the complexity of flexible manufacturing system,and the corresponding mathematical formulas is modeled.The hierarchical optimization method is applied to solve the multi-objective optimization problem,and the feasibility of the optimization method and scheduling strategy is verified through simulation experiments.Thirdly,we have studied the multi-objective mixed-model assembly line sequenencing problem based on the normal distribution of product assembly time.The mathematical model of the total expected overload times and idle time is established,which is optimized simultaneously with the fluctuation of material consumption and the total setup cost.The crossover operator,non-dominated sorting and crowding distance are embedded in MABC.We adopt multi-objective decision method to select non-dominated solutions that are obtained by the proposed algorithm.By solving several test problems suggested that the optimization method can solve the research problems.Finally,based on the above research related issues,the production scheduling software is designed and developed on the platform of Visual Basic 6.0.The practicality of scheduling software is verified by solving three practical cases.