Solution : https://service.sap.com/sap/support/notes/376279 (SAP Service marketplace login required)
Key words :
billable development effort, 6c support package 31, 6b support package 40, function group co2o, bapi_project_maintain eps reason, reference point, header-assigned, activity-assigned, activity element, actual dates
Related Notes :
| 571085 | OpenPS4MSP: New features in Version 2.X |