Research On Inventory Management Model Based On JIT

In the competitive market environment, it is important for enterprises to adopt effective supply chain management to reduce more cost and make more profit. JIT (just in time) plays a key role in managing and optimizing the supply chain. As the science and technology developing, all the enterprises are not independent units and they are combined with raw material suppliers, parts suppliers and assembly plants to make a whole related and open system. Manufacturing industry is being in the process of switching from the efficiency dominant system in the early phrase to the new quality dominant system which meets customers' various and changeable demand quickly.JIT has been already applied successfully in manufacturing industry and made achievement in reducing inventory and responding to customer demand quickly. To be more competitive, enterprise is involving JIT philosophy to supply chain management. The JIT philosophy combines JIT goods replacement JIT production and JIT delivery closely to make logistics synchronization. The effect of inventory management will affect the efficiency of JIT system directly, which is playing an important part in the supply chain harmonization. Enterprise managers and researchers care about how to realize the optimization of promptness and service quality which match demand fluctuation inventory control, bullwhip effect and the cost reduction.The first chapter of this paper integrates the research literature of some scholars and professors. Some of the viewpoints are quoted and some research status about system dynamics related to JIT is summarized for the reference. The first chapter elaborates the background and significance of the research, method and research structure.The second chapter expounds the main concept and therory of this essay. The concept and the theory about the inventory, bullwhip effect, JIT and System Dynamics have been quoted and analyzed. The conclusion about the inventory replacement has the characteristic of System Dynamics is drew in the paper. It is feasible for us to research the inventory replacement system.The third chapter compares two kinds of inventory replacement pattern. One way is that the replacement goods are delivered by suppliers directly (Vendor to Assembly-JIT), the other way is that the replace goods are delivered by the third party logistic (TPL to Assembly-JIT). The characteristic of traditional replacement method is also analyzed in the paper. The essay elaborates the economics meaning and advantage of TPL to Assembly is put forward for conclusion.The fourth chapter builds up the model of two inventory replacement (VA-JIT and TA-JIT) model in the JIT condition. The paper establishes the causal loop and systematic dynamics process chart in the condition of two inventory replacement theory foundation. The cause and effect, inner structure and mathematics relationship is defined via the method of system dynamics. The validity of the model is tested in the essay. The validity test contains test as following, boundary test, extreme test, sensitive test and active reappearance. The result proves that the system dynamics model has high validity for researching the inventory replacement. It is good model to emulate the real situation.The simulation analysis for system dynamics model is done in the fifth chapter. The research focus on two kinds of inventory replacement how to respond to two kinds of typical demand (step demand,random demand). The analysis takes raw material supplier, part supplier, the third party logistics and assembly suppliers as the research objects. By comparing two kinds of inventory replacement model, the paper analyzes the difference influences between two kinds of cycle time. The factors are inventory replacement period and supplier order process period. All of the above mentioned research may offer enterprises manager with reference when making decision.In conclusion, the bullwhip effect and the inventory fluctuation can be decreased by the two kinds of inventory replacement model based on JIT eviroment, according to the appropriate parameter. Especially, it is feasible that using system dynamics to understand influences that bullwhip effect and the inventory fluctuation affected by the parameter related to supply chain.