Using the ratio of unit holding cost and cost per shortage occasion M as multiplier,Lagrange multiplier method is applied to solve the problem. The specific meaning of M is also given.

• 以单位库存持有成本和单位缺货成本的比值M为拉格朗日系数,应用拉格朗日乘数法求解该模型,并应用边际理论说明了M的实际意义。