The key thing is that the maintenance schedules that all modern armies use are based on solid statistical studies, and a good understanding of the design specifications.

In contrast, Formula 1 teams have discovered that they used to be doing things all wrong: it was standard practice to strip an engine down after every race to check for defects, but recent rule changes that meant an engine had to be able to last for more than one race, actually made them more reliable - those that had lasted one race distance had proved themselves to be free from major defect, and were better left alone. Those that were rebuilt had an increased risk of a fault being introduced.