Ask a COO what their first automation deployment saved and the answer arrives with a caveat attached. The numbers exist. They just do not compare to anything.
Structure causes this, not carelessness
Every supplier instruments its own pilot and reports in its own format. That makes complete sense from where they sit, and a good supplier should do exactly that. Nobody supplies the common yardstick. The most diligent buyer in the sector ends up holding four honest reports that cannot be added together.
What independent oversight actually requires
Three things. Telemetry the operator holds rather than reads. Rules the operator wrote once, that each supplier comes in under. Measurement applied on the same terms across them. AG-3 Telemetry, AG-4 Policy and AG-5 Compliance, in that order. The independence that matters is the operator's: being able to assess the whole operation consistently rather than one supplier report at a time.
Renewal forces the question
The question lands hardest at renewal, when a named person defends the line item in front of a finance committee. Work backwards from that date and you find out fast what your current reporting can actually evidence.