Machine Performance
Three respectable 90% terms multiply to 73%. OEE is a product, not an average, and that is the whole point of it.
— %
Availability times performance times quality
Everything depends on what counts as planned time and what counts as an ideal rate, and those two definitions are where OEE comparisons between plants usually fall apart — excluding planned maintenance and changeovers from planned time flatters availability, and setting the ideal rate to a conservative practical figure rather than the nameplate flatters performance. Fix both definitions before comparing anything, including against your own past. Expressing each loss back in minutes is the useful part: it puts the three on one scale so the largest is visible, which the percentages alone do not do.
Textile OEE: Availability, Performance & Quality Multiplier — free, with the formula and a worked example, at Textile School.