What would a QA/QC role in commissioning entail?

Specifically, if you were offered a position that specified you might need to carry out Quality Assurance or Quality Control on, say, a substation. Is that just a case of looking for broken or badly finished/made stuff, or the full greenline and testing of the substation, from the HV switchgear down to the aircons? Anyone have any experience in it?

Thanks lads.