Diagnosis
You want to bill a sales document according to resources, or carry outa sales price calculation. You bill more than once to the same billingWBS element in the sales document items. This can occur directly orindirectly by assigning an account to a lower-level WBS element in thehierarchy.

Procedure
Enter the sales document items you want to bill according to resources,or for which you want to create a sales price calculation. You mustassign them to different billing elements.