Depreciation of PR sched. line exceeds allowed value (&1/&2/&3)

What causes this issue?

Management approval: The quantity specification of a schedule line was
reduced and the new value is greater that the maximum value allowed
for quantity reduction (quantity &V4&%).
Document category scheduling agreement item, document number: &V1&,
document item: &V2&, schedule line &V3&

System Response

The document is forwarded to the responsible processor to be approved in
line with management approval.

How to fix this error?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.