The Aggregation window displays a hierarchical view of the
SKU Items that your company manages. This particular hierarchy shows Items
arranged according to Region, which is meaningful for this company.
The left pane selects the Item groupings that will appear in the
right pane (here, Items matching "West" and "Hospital"
are shown). The values under either all nodes or any given nodes
(such as East or Hospital under West, above)
can be "aggregated" into new Aggregate Items that you
can forecast and manage like any other regular SKU Item in your database.