关键词: 模具, 项目调度, 离散工期, 马尔可夫决策过程, 近似动态规划, 优先规则

Abstract: The scheduling of multiple concurrent projects that shares and competes for limited resources with uncertain activity durations is common in mold manufacturing practices,and there is still a lack of effective methods for this type of problem until now.By addressing the mold project scheduling problem with partial activity durations that followed a given discrete probability distribution,the mathematical model was constructed based on a Markov Decision Processes (MDPs),whose objective was to minimize the expected total weighed tardiness costs.To deal with the curse of dimensionality when solve an optimal policy of large-scale instance by traditional dynamic programming,the approximate approaches based on classical priority rules,genetic algorithm (GA) and Approximate Dynamic Programming (ADP) were proposed respectively.The constructed model and methods were validated by a random generated project instances.The experimental results showed that the proposed approximate methods could obtain the acceptable suboptimal or even an optimal result with a small computational cost,which had the ability to solve practical problems.

Key words: mold, project scheduling, discrete durations, Markov decision processes, approximate dynamic programming, priority rules