We have good equipment, BUT we do not have the interface adapters to connect between our test equipment and the DUT.

In some cases the issue is that we are making the wrong measurement (large signal vs. small signal).

We don't understand the sensitivities of the measurement, e.g. injection amplitude.

In some cases, we are using the wrong equipment for the job (electronic load).

In some cases we believe we can't make the measurement, so we don't.

We may not have understood why we NEEDED to make the measurement or what we were looking for in the results.