外文翻译--成组技术.doc

Group Technology Group technology (GT) is a very important methodology in today’s manufacturing significant. The reason for this is that group technology, when utilized to its fullest extent, can affect most areas of manufacturing, including design, process planning, scheduling, routing, factory layout, procurement, quality assurance, machine tool utilization, tool design, producibility engineering, and assembly. 1 Introduction Group technology is a simple concept that is used widely in various forms. For a variety of reasons, it is logical to collect and associate things based on features that they have in common. This approach is familiar to everyone for plants, animals, and chemicals. Such organizational structures have also been used for hardware and other obviously similar products within the manufacturing world. Group technology represents structured categorization of particular value to the manufacturing community. It is already widely used; perhaps 50% of manufacturing companies use some form of GT. Bath or lot production suffers from many inefficiencies due to part variety and the general-purpose nature (flexibility requirements) of machine tools in use on the shop floor. In fact, a Cincinnati Milacron study showed that 95% of the time a part spends on the shop floor is idle time, the other 5% is divided between setup and teardown of the machine tool. The future breakdown of the 5% of on-machine time was developed by Dunlap. Based on this estimate, only 24% of the 5% is time which actually involves cutting; i.e., parts are being machined during only 1.2% of the total time spent in manufacturing. Group technology makes possible the application of several methods of analysis which assist in making batch production more efficient by reducing part variety via part families and improving throughout and work-in-process inventory. It is for this reason that group technology is becoming a key concept in manufacturing. 2 Definition Manufacturing philosophy to some,