Abstract: In order to cope with demand uncertainty, firms can produce both finished products and work-in-process products before the demand is realized, and quickly finish the rest production process for the work-in-process products if necessary after the uncertain demand is known. The unsold inventory can be used to satisfy future demand. As a means to increase production flexibility, handling work-in-process products may increase the production cost. When optimizing the production decision, firms need to make a tradeoff between cost and flexibility. Our model studies the optimal multi-period production policy with uncertain demand and work-in-process inventory under the framework of dynamic programming. By analyzing the structural property of the objective functions and value functions, we find the optimal production policy is a modified base-stock policy. We also analyze the impact of different parameters on the optimal policy.

Key words: Production decision, base-stock policy, dynamic optimization, work-in-process

摘要： 为了更好地应对需求的不确定性,在需求实现之前,企业既可以生产成品直接满足需求,亦可生产部分半成品,在观察到实际需求之后短时间内迅速完成剩余生产环节以满足需求。未加工的半成品和未售出的成品可用于满足后续周期的需求。作为一种提高生产灵活性的手段,分阶段生产的方式会产生更高的成本。企业需要在成本和灵活性之间作出权衡,优化生产决策。模型通过动态规划的方法,研究需求不确定情况下考虑半成品库存的多周期生产决策问题,通过分析目标函数以及最优值函数的结构性质,推导出最优的多周期生产策略为修正的目标库存策略,并且分析了不同参数对最优策略的影响。

关键词: 生产决策, 目标库存策略, 动态优化, 半成品