关键词: 不确定可重入, 定点装配, 生产计划与调度集成优化, 期望值模型, 遗传模拟退火算法

Abstract: To meet the demand of integration management between plants and workshops,the integrated optimization of production planning and scheduling for fixed-position assembly workshop with uncertain re-entrance was studied.Based on analyzing the assembly characteristic of workshop,the value of expectation was used to describe the uncertainty of re-entrance,and a bi-level stochastic expected value model of integrated production planning and scheduling was presented,in which the upper-level was a production planning model with capacity restriction and the lower-level was a scheduling model of fixed-position assembly workshop with uncertain re-entrance.An alternant iterative method with a bi-level structure by modified genetic algorithm was proposed.Elite genetic algorithm was applied to solve the problem of production planning in the upper-level,and the genetic simulated annealing algorithm based on stochastic simulation was applied to solve the problem of scheduling in the lower-level.The production plan was obtained in the upper-level firstly and then put into the lower-level to get the schedule,and the schedule was then put into the upper-level to get the new plan.By such alternant iterative process,the optimization of production planning and scheduling was achieved simultaneously.The result of simulation examples indicated that the proposed model and algorithm were effective,which  provided a feasible method to make the production planning and scheduling for fixed-position assembly workshop with uncertain re-entrance.

Key words: uncertain re-entrance, fixed-position assembly, integrated optimization of production planning and scheduling, expected value model, genetic simulated annealing algorithm