Why purchasing approvals exist

A purchase order is a legal commitment. Once Lakeside Components receives PO 4500000123, Contoso Motor Co. has promised to pay $21,000 for rotors. Approvals make sure that commitments of a certain size or kind are seen by someone with the authority to make them before they leave the building. They are one of the most visible internal controls in procure-to-pay, and auditors test them every year.

What approvals protect against

• Spending beyond authority. Contoso's delegation of authority says who may commit how much. A buyer may commit up to $25,000; above that, the purchasing manager must approve.
• Buying the wrong thing or for the wrong cost object. An approver who owns the budget notices a $9,000 test bench charged to a cost center instead of an asset.
• Fraud and favoritism. A second person reviewing supplier and price makes it harder to steer orders to a friendly supplier.
• Errors. A misplaced decimal ($210,000 instead of $21,000) is caught before the supplier ships ten times what was needed.

Where approvals sit in procure-to-pay

Contoso approves at several points, and each has a different purpose. Requisition approval asks "do we need this, and is it charged correctly?" PO approval asks "is this commitment within authority and on good terms?" Service entry sheet approval (course sap-mm-206) asks "was the work done?" Invoice release (course sap-mm-204) asks "should we pay this variance?" Designing them together avoids two common mistakes: approving the same thing twice, and leaving a gap where nobody approves at all.

A blocked document cannot move

In SAP S/4HANA, an approval is enforced by blocking. A requisition item waiting for approval cannot be converted into a PO. A PO waiting for approval cannot be output to the supplier. That makes the control effective: it is not a report someone reviews afterward, it is a gate. It also means a badly designed workflow stops the business, which is why approval testing matters so much.

Thresholds are a balance

Every approval adds delay. Set thresholds too low and approvers rubber-stamp hundreds of small POs a week, which is worse than no approval because it looks like a control while checking nothing. Set them too high and large commitments go out unseen. Contoso reviewed a year of ECC purchasing data before choosing $25,000: about 8% of POs by count, but more than 70% of spend by value. That kind of analysis, shared with Dan and the auditors, is what makes a threshold defensible.

Approval rules also need an owner. When a threshold changes or a new plant opens, someone must update the workflow, test it and keep the evidence. At Contoso the procurement process owner owns the rules and the PMO lead, Grace, tracks changes as change requests, so the approval design never drifts away from the delegation of authority it implements.