Audit 12 kW

The EU insists that a regular audit on >12 kW airco's has to be done. As far a I understood, this audit is already performed in the UK. How is this going practically? Do you have to measure temperatures, pressures? How do you evaluate a VRV/VRF system where all working parmeters are always changing? How to evaluate an invertermachine? What paperwork needs to be done?
I'm a member of the Belgium working group on this issue and we don't need to invent the wheel again.