Measuring Demand Uncertainty Notations: D:Average demand per period p:Standard deviation of demand(forecast error)per period Usually assume the demand follows normal distribution Lead time is the gap between when an order is placed and when it is received.In our discussion,we denote the lead time by L. SEIEE AU406 10+ - SEIEE AU406 10 Measuring Demand Uncertainty  Notations:  Usually assume the demand follows normal distribution  Lead time is the gap between when an order is placed and when it is received. In our discussion, we denote the lead time by L