Abstract: In order to provide decision support for the material manager in Chinese Daqing oilfield in making rational purchasing plan to obtain the oilfield materials, considering the practical problems in ''purchasing", ''demand" and ''inventory" and their interactions, such as demand increasing in materials demand, shortage in warehouse capacity, and large growth in purchasing cost, this paper uses forecasting and optimization theory and constructs the decision support prototype system for purchasing and inventory management of oilfield class-A materials, which includes forecasting module, optimization module and adjustment and evaluation module. Furthermore, the numerical simulation using four kinds of materials in Yinlang warehouse shows 10.35%, 8.07% saving rate in 2009 and 2010 respectively. Finally, some improved suggestions on the system have been proposed in large-scale promotion in Chinese Daqing oilfield, such as dealing with the incomplete data, improving the prediction accuracy, designing fast algorithm to solve complicated model and completing the adjustment and evaluation module.

Key words: supply chain management, decision support system for purchasing and inventory management, oilfield class-A materials, ARIMA model, the capacitated lot-sizing problem