Fabrication Estimating And Remnant Stock Management

The material requirements plan can be generated automatically with ERP, but for sheet metal manufacturing it still relies on the manual operation. It is inevitable that there is remnant in fabrication in most sheet metal enterprises. The traditional manufacturing resource planning disregards the management and utilization of remnant. They are usually disposed as scrap, which price may be about one sixth of purchase price. With the more and more serious competition in market, the material cost has turned one of key factors to keep predominance in manufacturing enterprises during competition. It is obvious that the material cost management has been a bottleneck of improving enterprises'profits.In the thesis, the material requirements planning of plates are completely analyzed for sheet metal enterprises. An integrated model of manufacturing material cost estimating is presented, which is described in detail with IDEF0 function tools. For common sheet metal enterprises'demands, the ideal of utilization and management of remnant is put forward, and some key problems for remnants utilization and remnants inventory are discussed deeply, which is an important supplement for the theory of traditional inventory.Minimizing the remnants inventory may be the optimal objective in manufacturing. The author designed three methods to reach this aim, which are the whole optimization, the part optimization, and the triangle matrix method. Meanwhile, enlightened by the resolution of the"knapsack problems", the double structure code of genetic algorithm is introduced in the optimization of remnants inventory. The method of how to pick up reasonable remnants and how to reduce the computation amount during remnants utilization is researched, which may be valuable for realizing the management and utilization of remnants.A prototype system on fabrication estimating & remnant stock is developed to prove the algorithms and viewpoints presented in this thesis based on theory research.