Research Of Logistics Systems Integrated Design Models And Optimization Algorithm

The efficient and effective logistics system is important determinant of modern logistics operation performance and the crucial foundation of logistics cost as reduction as possible. Logistics system design need make such four decisions as service level, strategic facility location, tactic inventory control policy and operational transportation routing. These decisions-making factors tie up and exist widely trade-off relation each other. Due to the complexity of modeling and solution, these decisions-making factors are traditionally plotted out three independent hiberarchy, which is difficult to satisfy the demand of modern logistics system design. The integrated design modeling between facility location, inventory control and transportation routing and its solutions has been among the hotspot problems of modern logistics system theory and operation research. Based on character analysis of distinct manufacturing industry, the integrated design modeling and solutions of distribution logistics and supply logistics are made profound researches. This main results obtained in this dissertation may be summarized as follows:1. Logistics system design research literatures reviewThe logistics system sequential design research results such as location-allocation problem, inventory control policy problem with stochastic demand are first reviewed, which can provide the research base of logistics system integrated design; Such logistics system integrated design problems as location-routing, inventory-routing and location-inventory are reviewed, among which research hotpot, difficulty and drawback on modeling and solution are analyzed. Then the new emphases of logistics system integrated design research are discussed.2. Automobile logistics system integrated design problem researchAutomobile distribution logistics system is researched, in which the transportation economies-of-scale between plants and distribution centers is focused and the demand process at each retail outlet for each product satisfies Poisson distribution. The new distribution logistics system structure is designed, which utilize fully transportation economies-of-scale between plants, consolidation centers and distribution centers. The automobile logistics system integrated design model is presented, which provides an integrated view of transportation economies-of-scale, inventory and facility costs as well as service quality. The flow prediction algorithm is presented, which is embedded respectively in genetic algorithm and particle swarm algorithm to solve the high non-linear math model resulting from transportation economies-of-scale. Solution framework and key step of these hybrid intelligent algorithms are expatiated respectively. Many case study simulations are given to confirm the correctness of the optimization model and the effectiveness of the solution. According to such these critical parameters variety as penalty cost, inventory control policies and transportation economies-of-scale, the change rule of automobile logistics system design scheme is discussed.3. Location-inventory system integrated design problem under stochastic demandThe location-inventory distribution system design problem involving one supplier, candidate distribution centers and multiple retailers under normal distribution demand is studied in the background of building materials industry. Retailers adopt periodic review(R, s, Q)inventory policy, while distribution centers adopt continuous review(s, S)inventory policy. Considering the trade-off between inventory cost, shipping cost and facility location cost, the integrated 2-echelon inventory control policies with incapacitated facility location model is presented. A Lagrangian relaxation solution algorithm for realistic scale problem is proposed. A number of heuristics are listed for solving effectively sub-problems. Sub-gradient method is improved. Simulations are given to confirm the correctness of the model and the effectiveness of the solution. Finally, the sensitivity of potential cost reduction, compared the sequential approach, to changes in inventory control key parameters including demand variance, holding cost, lead-time and service level is discussed, which confirm the requirement and feasibility integrated location with inventory.4. Integrated product development process with supply logistics system design problem researchBased on the background of complex product manufacturing industry, the integrated product development process with supply logistics system design model framework is presented. The parts process mapping and decision-making process on outsourcing is designed in order to provide the operational and interactive means of the model framework execution.5. Logistics system integrated design decision-making prototype system research and developmentIn order to analyze and evaluate the presented models and their solutions, logistics system integrated design decision-making prototype system is developed, Framework of prototype system, system design based on UML and execution interfaces in part are outlined.The research results presented above enrich the content of logistics system design theory, and provide more sufficient scientific evidence for decision makers making logistics system design,which is worthy of practicable application.