How vehicle availability supports (or hurts) fleet profitability

What does a stopped truck in your yard cost? If your answer is limited to repair costs, you are looking at only a fraction of the issue.

The cost of a stopped vehicle goes far beyond the replaced part or workshop labor. It involves lost freight revenue, an unfulfilled contract, a penalty for an unmet SLA, an idle driver, fixed costs that keep running (insurance, IPVA — Brazil's vehicle property tax — and depreciation) and, ultimately, an operating margin that shrinks with each day in the yard.

Vehicle availability is not just a maintenance indicator for fleet trucks. It also has one of the main impacts on a carrier fleet's profitability, and treating it as such completely changes how you plan, invest and decide.

Below, learn about:

• The financial impact of availability on the carrier's EBITDA
• Reliability indicators: applying MTBF and MTTR in the fleet
• Correlation between tire condition, availability and fuel consumption
• Preventive maintenance planning for fleets
• Integration of technology and data to reduce time in the yard

Financial impact of vehicle availability on carrier profitability

First, if you are not yet fully familiar with “EBITDA”: this term represents operating earnings before interest, taxes, depreciation and amortization. In practical terms, it is the number showing whether the carrier's operation sustains itself.

And fleet mechanical availability directly influences this number, on both the revenue and cost sides.

On the revenue side, every available vehicle is one that can generate freight revenue. If your fleet has 100 trucks and availability is 85%, in practice you operate with 85 vehicles. The other 15 are incurring fixed costs without generating revenue.

If each truck generates an average of R$25 thousand in revenue per month, those 15 stopped vehicles represent R$375 thousand in unrealized potential revenue every month, with amounts in Brazilian reais.

Now imagine that more structured maintenance management raises availability to 93%. That is 8 more operating trucks. R$200 thousand more in monthly revenue capacity, without buying a single new vehicle.

Now, on the cost side, vehicles stopped by an unplanned mechanical failure generate corrective maintenance, which is consistently more expensive than preventive maintenance. Urgently purchased parts cost more. Emergency labor costs more. And rework (when the repair does not resolve the issue the first time) consumes resources that should already be applied elsewhere.

In addition, each unplanned stop may generate indirect costs from contractual penalties for missed delivery deadlines, the need to subcontract freight to cover lost capacity, and damage to relationships with customers who depend on your punctuality.

The relationship is ultimately direct: the greater the fleet availability, the greater the potential revenue and the lower the operating cost. The combined effect of these two forces moves EBITDA. That is why availability is not just workshop talk; it is also a boardroom discussion.

Fleet reliability indicators: applying MTBF and MTTR in the fleet

If mechanical availability is the outcome indicator, MTBF and MTTR are the process indicators explaining why availability is where it is.

MTBF (Mean Time Between Failures)

MTBF (Mean Time Between Failures) measures how long, on average, a vehicle operates between failures. The higher it is, the more reliable the asset. This means trucks run longer without issues requiring downtime.

In practice, MTBF reflects the quality of truck preventive maintenance. If your MTBF is falling, it means vehicles are breaking down more frequently, pointing to prevention failures, components reaching the end of useful life without scheduled replacement or chronic issues not being resolved at the root cause.

To calculate this indicator, divide total operating time by the number of failures in the period. If 10 trucks operated 2,400 hours in the month and recorded 12 failures, MTBF is 200 hours. This means that, on average, each vehicle operates 200 hours before a failure occurs.

MTTR (Mean Time to Repair)

MTTR (Mean Time to Repair), in turn, measures how long the team takes, on average, to return a vehicle to operation after a failure. The lower the MTTR, the faster the recovery.

This indicator reflects your maintenance structure's efficiency: parts availability in inventory, technical team training, workshop processes and access to precise diagnoses. A high MTTR indicates bottlenecks that may be linked to missing parts, slow diagnosis and/or an understaffed team.

To calculate it, divide total corrective-maintenance downtime by the number of failures. If the same 10 trucks spent 60 hours stopped for repair in the month and had 12 failures, MTTR is 5 hours per event.

The relationship between both indicators and availability

Mechanical availability can be expressed by the formula: MTBF ÷ (MTBF + MTTR). In the example above, that is 200 ÷ (200 + 5) = 97.6%. An excellent result, in fact.

But if MTBF falls to 100 hours and MTTR rises to 10 hours, availability plunges to 90.9%. This drop of almost 7 percentage points in a fleet of 100 vehicles may mean 7 fewer trucks operating each day.

The value of these indicators lies not only in the absolute number, but in the trend. An MTBF falling month by month is a warning sign before the issue appears in EBITDA. An MTTR that steadily increases may indicate the workshop needs more resources, better inventory or more efficient processes.

Correlation between tire condition, availability and fuel consumption

When mechanical availability comes up, the immediate thought is usually the engine, transmission, brakes and suspension. But tires play a more relevant role than many managers realize, in both availability and fuel consumption.

Downtime caused by tire-related issues, such as blowouts, recurring punctures and premature wear forcing an unscheduled replacement, is more frequent than it should be in fleets without structured tire management.

Each such event creates unavailability: the vehicle stops, waits for assistance (internal or external), receives service and returns to operation. For road blowouts, this can take hours.

Tire preventive maintenance reduces these events, and every tire-related stop avoided preserves fleet availability.

In addition, tire condition directly affects fuel cost (already the fleet's largest operating cost).

Studies indicate that a 10% reduction in tire pressure may increase fuel consumption by up to 1% to 2%. That may seem small for one vehicle, but in a fleet of 100 trucks each driving 15 thousand km per month, the annualized financial impact is substantial.

Uneven wear also affects diesel consumption. Tires with asymmetric or compromised wear generate vibrations, increase resistance and demand more from the engine. Besides increasing consumption, they accelerate wear on other mechanical components, such as suspension, bearings and axles.

The connection is clear: keeping tires in good condition directly contributes to two critical areas: fleet availability and operational energy efficiency. Two impacts on EBITDA from the same area of focus.

Preventive maintenance planning for fleets

If availability is the goal, preventive maintenance is the way. No fleet with high mechanical availability operates by waiting for breakdowns before repairing. Preventive maintenance planning for large fleets needs to be structured, not intuitive.

And that involves some fundamental elements:

• Maintenance plan by vehicle and component: each vehicle should have a defined maintenance plan, with servicing intervals based on mileage, hour-meter readings or time (whichever comes first). Items from the manufacturer's manual, but also components requiring special attention in the specific operation — brakes on mountain routes, suspension on unpaved roads, tires in long-distance operations.
• Scheduling integrated with the operational calendar: scheduling needs to be integrated with the operations calendar, taking advantage of lower-demand windows, periods between trips and scheduled stops that do not compromise service capacity.
• Parts inventory management: inventory of critical parts (filters, belts, pads, suspension components, tire items) needs managing to ensure predictability, minimum stock and consumption control.
• Standardized execution: standard operating procedures for each service type ensure preventive maintenance is performed the same way, every time, by any technician. Standardization reduces rework, reduces execution time and ensures no stage is skipped.
• Recording and traceability: each preventive service needs recording, from what was done, when and by whom to which parts were used and the component's condition at the time of intervention. This history feeds reliability analysis (MTBF), makes it possible to identify problematic vehicles and supports asset refurbishment or replacement decisions.

The result of all this? Fewer corrective stops, higher MTBF, lower MTTR and, consequently, higher mechanical availability.

Preventive maintenance costs less than corrective maintenance, requires less downtime and creates predictability, precisely what a carrier needs to keep contracts and customers.

Integration of technology and data to reduce time in the yard

In large fleets, maintenance management based on paper or a vehicle availability spreadsheet (in Portuguese) has its limits. It works up to a point, then starts costing more than it solves.

A dedicated system centralizes each vehicle's maintenance plan, triggers automatic alerts when a preventive service approaches, records each intervention and generates a complete asset history. This eliminates dependence on human memory and reduces the risk of late or forgotten maintenance.

In addition, the system allows cross-analysis: which vehicles stop most frequently? Which components fail most? What is the MTBF by vehicle model, operation type and mileage range? These answers turn data into decisions.

Fleet availability is not an isolated indicator confined to the workshop. As you can understand by now, it influences the operational and financial health of your road freight transport operation.

Each additional percentage point of availability translates into revenue generated, cost avoided and a contract fulfilled.

But maintaining this availability in fleets with dozens or hundreds of vehicles takes more than spreadsheets and goodwill. It requires a system, processes and integrated data. This is what Prolog Maintenance Management is for: centralized preventive planning, automatic alerts, complete vehicle history. Your fleet indicators are updated in real time as the team records inspections and workshop work.

Discover the solution and see how it can keep your fleet running (and protect your margin).