A Study on Evolutionary Reactive Ordering Systems

为了开发多阶段生产系统的敏捷订货系统，本研究提出了一种缓冲库存的反应控制器，以应对需求的不稳定变化。在控制器中，不稳定的需求变化，不仅是平均值，而且方差，可以检测到，和缓冲库存的最佳水平被确定为使用指数加权移动平均（EWMA）图表的变化的反应。除了使用EWMA图的控制器之外，还针对看板系统和并发订购系统这两种类型的即时（JIT）订购系统提出了使用神经网络的控制器。在各种不稳定的需求条件下，所提出的系统的有效性进行了澄清的仿真实验。仿真实验结果表明，该控制器能够对需求的不稳定变化做出反应，不仅能对需求的均值做出反应，而且能对需求的方差做出反应，同时满足产品需求的平均等待时间的要求。此外，它可以表明，所提出的控制器使用神经网络减少了系统的平均在制品库存比以前的控制器使用EWMA图。

In order to develop an agile ordering system for multi-stage production system, this research proposed a reactive controller of buffer inventory for reacting to the unstable changes in demand. In the controller, the unstable changes in demand, not only the mean but also the variance, can be detected, and the optimal level of buffer inventory is determined as a reaction to the changes using the exponentially weighted moving average (EWMA) charts. In addition to the controller using EWMA charts, a controller using a neural network is proposed for two types of just-in-time (JIT) ordering systems, the Kanban system and the concurrent ordering system. The effectiveness of the proposed system is clarified by the simulation experiments under various unstable demand conditions. As a result of simulation experiments, it is shown that the proposed controller can react to the unstable changes in demand, not only the mean but also the variance, with satisfying the required level for the mean waiting time of product demand. Furthermore, it can be shown that the proposed controller using neural network reduces the mean work-in-process inventories of the system much more than the previous controller using EWMA charts.