Progress and survey
The site measured from the air, compared to the design.
Survey and volumetrics
Cut and fill measured against design by photogrammetry, weekly or daily.
As built against plan
Deviations from design located early, while they are cheap to fix.
Progress against programme
Physical progress mapped onto the schedule, so variance is visible the same week.
Claims and variation evidence
Dated, measured imagery that settles disputes before they become claims.