Development and evaluation of next generation production and distribution systems

准时化(JIT)生产系统的发展是为了提高质量、降低成本和加快小批量生产中品种繁多的交货速度。这是一种按顺序提取并随后使用看板进行补充的拉式系统。另一方面，MRP(物料需求计划)是一种推式系统，它以时间段为单位，通过供应和生产订单来扩展零件层次，控制零件和产品。OPT(优化生产技术)也是一个推式系统，它试图实现最优调度，最大化瓶颈阶段的利用率，减少提前期，并保持最优库存水平。然而，在当今瞬息万变的形势下，推送系统已经不能适应环境。分散式自治生产系统是功能强大的下一代生产系统，每个阶段都是分散自治的。本文通过对实际生产系统的观察，展示了采用JIT、MRP和OPT的生产系统的特点和实际性能。在考虑未来技术创新(计算机、通信和制造)、环境问题、资源和能源问题的各种情景下，我们研究了实际生产系统的未来发展以及分散自治系统等未来生产和分配系统的可行性。此外，在各种场景下，我们构建了可行的下一代生产和分销系统。利用生产模拟器ROPS II进行了性能评价和经济分析。获得了对环境做出积极或中性贡献的下一代生产和分配系统的基本类型。

Just-In-Time(JIT) production systems have been developed for improvement quality, reducing cost and expediting delivery under great variety within small quantities production. This is a pull system that is sequenced withdrawal and later-replenished by using Kanbans. On the other hand, MRP (Material Requirements Planning) is a push system that expands part levels and controls parts and products by supply and production orders in the unit of time bucket. OPT (Optimized Production Technology) is also a push system and attempts to attain optimal scheduling that maximizes utilization of bottleneck stage, reduces lead-time and keeps optimal inventory level. However, under suddenly changeable situation of today, push systems can not adapt the environments. Decentralized autonomous production systems, in which each stage is decentralized and autonomous, are powerful next generation production systems.In this study, features and actual performance of practical production systems employing JIT, MRP and OPT are shown through their observations. Under various scenarios considering future technological innovation (computers, communication and manufacturing), environmental issues, resources and energy problems, we investigate future developments of the practical production systems and feasibility of future production and distribution systems such as decentralized autonomous systems. Moreover, under the various scenarios, we construct feasible next generation production and distribution systems. Their performance evaluation and economic analysis are executed by using Production Simulator "ROPS II". Basic type of the next generation production and distribution systems are obtained that contribute positively or neutrally to the environment.