SAP Note 18128 - Create purchase order: pur. req. is not blocked

Symptom:

Key words: ME21, ME22, ME57, ME58, ME59
Create purchase order with reference to purchase requisition: several users can create purchase orders with reference to the same purchase requisition, but the purchase requisition is not blocked.

Cause and prerequisites

This is not an error!
The purchase requisition is intentionally not blocked.
Reason: before a purchase order with reference to a purchase requisition is created, a list of purchase requisitions is normally generated (for example, selection by material number or purchasing group - not usually selected directly with the requisition number). Based on this list, the user selects one or more purchase requisitions. However, the requisition cannot simply be blocked after selection; all the purchase requisitions appearing in the corresponding selection list would have to be blocked before display.
Because these lists can be quite long, block situations would quickly occur that would prevent "normal" work.
Because specific purchasers are usually assigned to specific purchasing groups (organizational arrangement), these purchasers normally only select purchase requisitions with an assigned purchasing group. In such cases, the above situation can almost never apply.

Solution
An organizational solution to the problem is required.

Additional key words

douple, twice, parallel, 06589, 06 589