Underwrite this against one number: vehicle utilization. Every point of utilization you recover is revenue earned by trucks you already own and drivers you already pay - no new equipment, no new hires. The mechanism is direct: fewer breakdowns means fewer towed loads, less spot-market coverage, less empty repositioning, and technicians working from scheduled work orders instead of emergency repairs. Fuel per unit follows, because a healthy fleet spends less time on inefficient recovery routing.
Set the targets as stated assumptions before you sign anything, then hold the system to them: a measurable drop in unplanned downtime within the first quarter after go-live, and maintenance labor shifting from firefighting to scheduled work. The return compounds from there. Prediction accuracy improves as the model ingests more of your operating history, so the system scoring your fleet in month twelve is working from a year of your actual failure data, not a manufacturer's service interval.