Procurement Processes and Customizing
The objects that control procurement behaviour
Most customizing questions resolve to a handful of objects. Document types control number ranges, field selection, whether numbers are assigned internally or externally, and which item categories (and, with them, which account assignment categories) may be used. Item categories control the item-level layout and behaviour - whether a plant, material, delivery date or service fields appear, whether goods receipt and invoice receipt are allowed, and which account assignment categories are permitted. Field selection is defined per document type, per field, per activity (header vs. item) with four states: suppressed, display, required, optional. Number ranges are assigned per document type; two document types can share one number range.
Document types worth memorising: NB (purchase requisition and purchase order), AN (inquiry), ANQ (quotation/RFQ), MK (contract), LP (scheduling agreement), UB (stock transport order).
Release procedures are classification-based. You define release characteristics (typically total value), a release strategy that combines characteristic values, release codes assigned to strategies, and a release indicator that determines whether a change resets an existing release. Purchase requisitions can be released item-wise or with overall release - an indicator on the requisition document type, not a user setting.
Traps: field selection is not user-specific (that is authorizations); editing a released document may reset the release depending on the release indicator; the same document type name can appear for PR and PO because the number range object differs; GR-based invoice verification is a PO item indicator, not a document type setting.
Rule of thumb: ask at which level the behaviour lives - document type for document-level defaults, item category for item-level behaviour, release strategy for approvals. Example: a PO for 12,000 EUR is blocked because the strategy matching its plant and value band has not been released by all release codes; raising the quantity into a higher value band moves it to a different strategy and restarts approval.