3590615 - How to identify PAL Overallocation Situations in advanced ATP

Based on an aATP check, PAL check details of one or more PAL bucket(s) may show a negative value in the column for the "available allocation qty".
Such situations are called "overallocation situation" and might be caused, e.g. by reducing the planned PAL quantity or by using the constraint status 'unrestricted quantity' without ensuring suitable follow up processes.
Hardcoded in the SAP Standard program logic, such negative quantities will have to be "resolved first", which will cause unexpected and undesired PAL decisions for the most current planned periods. 
To resolve the issue you may increase the planned allocation quantity in the PAL buckets with the negative values.

The question, that this SAP KBA will answer is: How can such PAL "overallocation situations" be identified?

DISCLAIMER: Image/data in this KBA is from SAP internal systems, sample data, or demo systems of release S/4 HANA 2023. Any resemblance to real data is purely coincidental.