Solution : https://service.sap.com/sap/support/notes/191907 (SAP Service marketplace login required)
Key words :
open quantity - check fixed quantity id, rules-based availability check, rule-based availability check, additional key words v1601, system issues message v1601, fixed quantity indicator, = sourcing main item, sourcing main item, sourcing main items, apo = advanced planner
Related Notes :
| 180929 | Problems during availability check in sales order |
| 179948 | Processing sales documents with SAP APO |
| 151153 | V1601 displayed with fixed qty indicators |