The stock population is the number of stock management units that belong to an inventory sampling. These stock management units are clearly defined by the allocation of the stock management levels for an inventory sampling. This allocation process also defines the stock population. However, the stock management levels themselves contain no information about the stock management units. For this reason, the stock population must be created in a separate step after the allocation of the stock management levels. Afterwards, you can change the stock population until you start the random selection. When creating the stock population, the system checks if there is already an active physical inventory for each stock management unit of the allocated stock management levels. If this is the case, then the stock management unit does not belong to the stock population. The stock population is divided into sampling area and complete-count area.

The term sampling area means the quantity of stock management units in an inventory sampling, of which only a selection has to be counted. Elements are drawn by random selection from the elements of the sampling area. The elements selected are counted, and their physical inventory results are extrapolated to the sampling area.

The term complete-count area means the quantity of stock management units in an inventory sampling, of which all have to be counted.

A stock management unit is an element of the complete-count area if:

• The book inventory is zero.
• The deletion indicator is set for the material in the material master record.
• The material shows a certain ABC indicator.
• The price of the material exceeds the upper price limit.
• The value of the material exceeds the upper value limit.

The sampling area of an inventory sampling usually contains many stock management units with very different values. The bigger the margin between the smallest and largest values, the more stock management units must be counted in order for the statement to be statistically reliable. To reduce the number of counts necessary, the system splits the sampling area into classes, so that elements in a certain class have (approximately) the same value. Using classification, the system can later create strata where the random selection and the extrapolation are performed separately. A class is therefore the number of stock management units in a sampling area that fall within a certain value interval. All intervals (possibly with the exception of the last one) are equal in size, but usually contain different numbers of stock management units. The classification of the sampling area occurs automatically when the stock population is formed. For this the system uses the parameters you set.