FAQ - Why condition the calculations?
Just like any other field, a calculation must be assigned to a Data Group. By conditioning the first calculation on the value of the Warehouse Identifier, we are actually defining a new field in group G01 - the DATA GROUP to which Warehouse Identifier belongs.
The value that we want in this field is 1 regardless of any conditioning. The purpose of the condition is to ensure that the field is built with this value every time group G01 is built (so that it is done for each Warehouse record we read). Totalling this field at the report level will always produce a value equal to the number of records from the Warehouse file that are accepted for processing by "this" report run.
Without conditioning, this field would only have to be built once for the entire report - it would be a CTL group field.
Conditioning the second calculation using the Product Number field causes it to be placed into group G02.