(Feedback from Statistics Estonia; 5 October, 2017)
"4.1. Create frame and select sample" is the only sub-process, that covers underlying registers. 4.1 says, that "maintenance of underlying registers ... is treated as a separate business process".
To some extent the management of business register is covered in GAMSO 1.0 sub-process "3.6 Manage information and knowledge" - but not that clearly.
We see a need for more detailed descriptions in GSBPM or in GAMSO.