Study on IT-based Evolution of JIT production systems

由于信息技术革命，信息成本正在迅速降低。在本研究中，我们试图通过充分利用IT来发展JIT生产系统。本研究取得以下五点成果：1.由上述研究者等人撰写的日文学术著作《准时生产系统》于2004年由日刊光友新闻社出版。2.将随机需求下的多阶段故障生产配送系统的最优控制问题表述为一个无折扣马尔可夫决策过程，使单位时间期望总成本最小化。一个新的神经DP算法称为SBMPIM的开发来解决这个问题。此外，还将基本库存、看板和连续生产等拉动式生产系统的单位时间期望总成本与SBMPIM计算的单位时间期望总成本进行了数值比较。3.针对复杂约束条件下的混流装配线优化问题，提出了实用有效的求解算法。5.提出了求解三维装箱问题和车辆路线问题的实用元启发式算法，以实现基于JIT思想的配送系统优化。

The information cost is reducing rapidly due to the information technology (IT) revolution. In this study, we attempt to evolve JIT production systems by utilizing IT fully. The following five points are the results obtained through this study :1.An academic book "Just In Time production system" was written by the above investigators and others in Japanese and was published by Nikkan Kougyou Shinbunsya in 2004.2.An optimal control problem for a failure-prone multi-stage production and distribution system with stochastic demand that minimizes expected total cost per unit time is formulated as an undiscounted Markov decision process. A new neuro DP algorithm called the SBMPIM is developed to solve the problem. Moreover, the expected total costs per unit time of pull production systems such as Base stock, Kanban and CONWIP are numerically compared with the expected total costs per unit time computed by the SBMPIM.3.Practical and efficient algorithms are developed for solving optimization problems of mixed-model assembly lines with complex constraints.4.Performance evaluation algorithms of various types of cell production systems, which are adapted to diversification of customer demand and a short product life cycle, are development by organically combining queueing theory with simulation.5.Practical meta-heuristic algorithms for solving three-dimensional packing problems and vehicle routine problems are developed to attain optimal distribution systems based on the JIT philosophy.