Four levers separate the low-downtime windows from the high ones
Strategy, spare-parts availability, crew skill and PM discipline each split downtime by roughly 2x to 3x, and every one of those splits survives a Bonferroni-corrected test. Reactive runs 2.3x predictive, shortage 2.9x available, basic crews 1.8x expert.
Downtime by maintenance strategy, with 95% intervals study
Mean unplanned hours per observation. Non-overlapping intervals mean the ranking is reproducible. Preventive, condition-based and predictive overlap: the step that matters is leaving reactive.
Downtime by spare-parts status, with 95% intervals study
All three intervals are clear of each other: each step up in availability is a real reduction.
Downtime by technician skill, with 95% intervals study
Basic and intermediate crews sit clearly above advanced and expert.
Downtime falls as PM compliance rises
Mean downtime per observation, by PM-compliance decile (D1 = least compliant). Live.
Lever thresholds: below versus above study
Each lever split at a practical operating threshold. p-values from one-way ANOVA; η² is the share of downtime variance the split explains.
Revenue loss climbs steeply as health falls
Mean revenue loss per observation by Asset Health Index band. Live. Windows under 70 lose about 9x the 90+ band.