Solution : https://service.sap.com/sap/support/notes/420382 (SAP Service marketplace login required)
Key words :
additional key words iw31, pm/cs order, manual screen change, field caufvd-func_area, functional area field, caufvd-func_area, functional area, input field, output field, order type
Related Notes :
| 921112 | The functional area field is only 4 characters long |
| 439009 | Object class Customizing for PM/CS orders |
| 317710 | Functional area field is invisible in PM/SM order |