A Study On Inventory Model Of Component Commonality Safety Stock Based On Supply Lead Time

With the intensification of the global competition, the companies play more attention to the customers'demand. The customers have more requirements for the product or service under the development of economy and the progress of technology, and the variety and uncertainty of the demand become more significant. As a main technology of Mass customization, component commonality can meet the individual demands effectively. Moreover, component commonality has more priority to reduce the procurement lead time. It may be quicker to procure a single component rather than a set of unique components,which is better to control the cost of inventory system. Therefore, with the increase of uncertainty in supply chain and changing procurement lead time, setting appropriate safety stock of component commonality is not only better for meeting individual demands, but also useful to optimize the total cost under the high service level constraint.Based on the previous research, this thesis starts with a model which considers the component commonality safety stock under the optimization of total cost with service level constraint and the presence of component procurement lead time. It occurs in the assemble-to-order environment where components are replenished according to a (Q, r)-policy with lead time demand following the normal distribution and any number of products and components. Through comparing the strategy of commonality with the strategy of no commonality, both the changing rules of component commonality safety stock and the joint safety stock of no commonality based on the procurement lead time are studied. And the effect of the changes of other parameters in inventory system on safety stock is further analyzed. Then extends the first model to consider the controllable procurement lead time with the lead time crashing cost .The model is developed to consider the component commonality safety stock under the minimum of total cost when the distribution of lead time demand is unknown and certain service level requirement. The effects of controllable lead time on component commonality safety stock, shortage rate and total cost are discussed through the data analysis.