Acceptable to offset tolerance band?

Question

For validation tests, it is quite common to get slight deviations in the trim/starting conditions with regard to the reference data which, although within tolerance, effectively reduce the allowable margin for the simulator responses. Might it be acceptable to offset the tolerance band so as to be centered in the actual trim/starting conditions during the test?

Answer

It is common to have some reference values offset at the start of a test but are you asking if you can offset the tolerance centre point for the whole plot so that would effectively mean instead of +/- 5% (or whatever) it becomes +8/-3% (or whatever)? That would be unacceptable in so much as we believe the tolerance is specific to a piece of A/C data at a specific time.