In the fundamental production inventory model, in order to solve the economic production quantity (EPQ) per cycle, we always fix both the demand quantity (r) and the production quantity (d) per day.

• 摘要在基本的生产库存模型中（即在清晰情况下），为了求解每周期的经济生产量，总是把每天的需求量和生产量看作常量。