Studies On The Dynamic Version Of The Economic Lot Sizing Model With Transportation Costs And Multi-suppliers

Lot-sizing problem is one of the most important subjects in the fields of enterprise production and business management. The scientific organization of production and purchasing activities applied by the lot sizing optimal model, is one of the necessary conditions for reducing production costs and raising profit rate in enterprise. As the development of the globalization of market competition, logistics has occupied an increasing important position in the operational processes, such as raw and semifinished materials purchase and production distribution, the transportation costs has played an increasingly predominant ratio in the total production costs on one hand, and the scientifically rational selection of suppliers and assignation of purchase quantity could effectively reduce the procurement cost on the other hand. Therefore, the establishment of models for the dynamic version of the economic lot sizing problem (DELSP) with transportation costs and multi-suppliers, and the relative solution methods, has been of theoretical significance and practical value.Having based upon the former research achievements in DELSP, the dissertation has studied the lot sizing problem with transportation capacitated and additional transportation capacity on the spot market, the optimal decision problem integrated production and transportation with combined use of multi-type transportation tools, the lot sizing problems with multi-suppliers uncapacitated and single or multi-products, and with multi-suppliers capacitated and single product. The corresponding research results and creativities have been briefly described as follow:(1) Having established an optimum model of DELSP with transportation capacitated and additional transportation capacity on the spot market, and studied a Lagrangian-based heuristic algorithm (LagHA) for the solution of the model. The comparative results between the comprehensive computational experiments of LagHA and the simulation experiments of CPLEX have showed that the performance of LagHA in term of speed is obviously more excellent than that of CPLEX (ATim(s)<