SAP Message BP603 - Item & budget exceeded

Diagnosis
Budget &V3& was exceeded by &V4& in document item &V1& &V2&.

734808MIR4: Error message BP603 when simulating
511650MIR4: BP603 during simulation
926322Unjustified error in budget check
1554753Follow-on Note of Note 1423384
1557793Classic Scenario: unexpected budget error for SC with PR