There are many business in Taiwan that their production type are indistinct between make-to-stock and make-to-order. This kind of production type can shorten the lead time of order and decrease the fluxion of customer¡¦s demand, on it¡¦s technology of predicting customer¡¦s demand for pre-production and inventory. Thus, the efficacy of production must depend on it¡¦s precision of predicting customer¡¦s demand. Recognition that traditional work order dispatching made to some specific standardization. Therefore, it is leaded to customization product and less flexible. And the decision-maker must choose one goal between minizing inventory cost, WIP¡¦s level and lead time. The production type, work order dispatching must have flexibility,and it must accomplish the customer¡¦s order on time considering inventory cost and customer service. This thesis hopes that it would be to develop a work order dispatching method to improve the efficiency of WIP administering, the flexibility for work order dispatching and decreasing lead time of customer¡¦s order. According to production¡¦s characteristic of different manufacturing stage, it can create one applicable dispatching rules to increase the production efficiency. Finally, using simulation software, applying to case study comparing the performance of the real case and new work order dispatching