Cross Sectioned Data consists of observations we derive from the analysis of demand across all service parts.
The Prior Distribution of service part demand levels relies on observing the cross section of
demand levels for the service parts.
If we take the mean annual demand level per part and put that demand in a histogram bucket and we do this across all parts we get the Prior Distribution of the service parts in the form of a histogram.
When we look at the parts that have a demand level of 2 per year, we may find that 5 parts out of 200 have a demand level of 2 units per year. We are looking at a segment of the cross section of our data.