Demand Processes and Demand Prediction

When the George AFB field test, described in Chapter 1, was conducted, several people asked us why an inventory model was needed at all. They suggested that to find out what is needed all one has to do is ask an expert, the supply sergeant. There was one particular sergeant who had kept a little black book after a thirty day deployment exercise. In his words, “We took a lot of stuff we didn’t need, and we needed a lot of stuff we didn’t take. But I know exactly what we need next time, and that’s all we’re taking.”

The sergeant’s data could certainly be useful, but his understanding of the problem was flawed because he did not recognize the importance of variability. If items with demand during the previous exercise are the only ones taken on the next exercise, it is certain that there will be demands for other items.

An erratum to this chapter is available at http://dx.doi.org/10.1007/b109856_11