Bill of Material(BOM) and Low-Level-Code(LLC) are important inputs of the MRP-system,to design an effective algorithm for the BOM expandedness and LLC calculation is a key thing to promote the efficiency of the MRP-system.

• 物料清单(BOM)和低层码(LLC)是MRP系统的关键输入,寻找一种高效的BOM遍历和低层码生成算法,是提高MRP计划编制效率的关键。