The Benefits of Predictive Maintenance

The entire area of commercial vehicle maintenance has evolved over the past six decades, and that’s a positive move for the industry and its vehicles. Properly caring for trucks, tractors and trailers has advanced from a “just fix it” mindset, to technicians keeping a watchful eye for likely trouble spots or failure-likely components and systems, to the formal preventive maintenance, to today’s more popular predictive maintenance.

Traditionally, fleet maintenance managers and industry suppliers have used reliability statistics from standardized testing to structure preventive maintenance intervals and schedule fluid or component replacements and tire rotations.

Going forward, real-time technologies and actual fleet data are replacing these old methods. This will significantly reduce maintenance costs, improve vehicle performance, improve vehicle emissions compliance and increase vehicle time in-service (uptime).


Interestingly, one common element crosses all the evolutionary steps: solutions. From the most elementary stage of “just fix it,” to the data-driven solutions of today, there has been tremendous improvement, plus a steady progression towards preventive maintenance.

Nearly a decade ago, a Technology & Maintenance Council technical session from March 2003 reported on the Sound Science for Fleet Prognostics. The exploratory paper was produced as a framework for things the industry should be watching.

Nine years later, the main value of predictive maintenance remains to allow convenient scheduling of corrective maintenance and to prevent unexpected equipment failures. This approach offers cost savings over routine or time-based preventive maintenance.

Vehicles and respective owners have benefitted from the ability to transport more freight and goods more efficiently to consumers and businesses across North America.

The key has been having the right information at the right time. By knowing which piece of equipment needs maintenance, the maintenance work can be better planned for parts and people resources. Plus, what would have been “unplanned stops” are transformed to shorter and fewer planned stops, thus increasing plant availability.

Other values are increased equipment lifetime, increased shop safety, fewer accidents with negative impact on environment and optimized parts inventory and usage.


All on-highway trucks and tractors now have a minimum of four computers, and most have as many as six. A recent examination of a late-model tractor revealed a separate onboard computer for each of these systems: engine, exhaust, cab, antilock braking system, driver side airbag, automated manual transmission, in-dash driver center and a management/driver log system.

These onboard computers are known as an engine control or electronic control module (ECM) or electronic control unit (ECU). Along with running the operating systems for the component they were designed with, these computers also monitor sensors for variances that are outside of their normal operating parameters.

These variances, called fault codes, are logged and stored into the system’s memory as they occur. When an inactive fault code become active or severe, then a dash-mounted malfunction indicator lamp (MIL) is turned on to warn the driver about system malfunctions.


As vehicles get connected to the Internet via telematic systems, more and more maintenance managers are collecting performance data into their maintenance systems and receiving e-mail messages from their vehicles. The e-mail messages let managers know about both active and inactive fault codes as they occur.

The e-mail messages can also include GPS location information, ambient temperature and other critical information that can be vital to help diagnose the root cause of the fault code. With such information, a fleet maintenance manager can direct the driver to a repair location if component failure may be immediate, or order parts and have them ready if the fault codes are inactive and the vehicle can safely and reliably run back to the home base location.

The data collected from the vehicles includes many buckets of both detailed and summarized statistics, including:

  • Miles per gallon.
  • Gallons of fuel consumed.
  • Gallons of diesel exhaust fluid consumed.
  • Total miles.
  • Trip miles.
  • Engine hours.
  • Idle time.
  • Sleeper time.
  • Miles run in top gear.
  • Miles traveled in cruise control.
  • Number of hard stops.
  • Miles traveled with an in-dash MIL lamp on.
  • Top speed.
  • Time at various speeds.
  • Time/miles in engine RPM bands.

This data can be analyzed to determine the performance of both the vehicle and the driver.

Telematics technology has become so helpful to fleets using it they are now beginning to ask suppliers to add sensors onto the vehicles to gather more data and monitor more systems, such as: tire pressures, oil quality, filter plugging status, battery life, brake life, alternator performance and starter amp draw.

Of course none of this data is of any value to the fleet if they don’t start to collect and systematically analyze it.

It is easy to imagine a future where fluids and components are not changed based simply on time, miles and or some statistic generated in a lab environment on expected life. Rather, they are changed based on actual performance degradation onboard the vehicle in real-time.

Predictive maintenance helps technicians determine the condition of in-service equipment in order to predict when maintenance should be performed. This approach offers cost savings over routine or time-based preventive maintenance because tasks are performed only when warranted.


Without a doubt, strategic predictive maintenance is a key component of achieving lowest cost of ownership. This is an untapped opportunity for fleet managers to lower their costs through more sophisticated, data-driven predictive maintenance systems that are currently available.

Nowadays, fleet managers are more aware of costs and simply must produce more uptime and fewer breakdowns. Predictive maintenance systems can help with this by supporting vehicles more proactively, than reactively.

Making proper use of the data is the key. That data can and will influence driver behavior for optimum operation, which means reduced maintenance costs, and determining a fleet’s individual, accurate maintenance schedules.


Realizing the overall net savings potential of shortening the equipment lifecycle may be the most under-utilized predictive maintenance strategy of all.

The data mining capabilities today, matched with good analytics, can actually pinpoint the moment when the cost of even the most efficient preventive maintenance schedules, combined with other factors, becomes higher than the overall cost of replacement. Determining that tipping point, and acting on it quickly, is truly a critical predictive maintenance decision.

Elaborating on the benefits of good, solid vehicle performance data and lifecycle management, John Flynn, CEO of truck lessor Fleet Advantage, says: “Applying business intelligence tools to that data can get you a true total cost of ownership. And that goes beyond fuel consumption, and considers a wide range of lifecycle costs that change over time.

“Total cost of ownership isn’t a simple math exercise done when you originally purchased a truck. Fuel costs change, the fuel economy potential of equipment changes, replacement part costs change.

“The most accurate lifecycle analysis needs real-time data because the factors that drove the initial lifecycle decision have changed, and so should the vehicles replacement strategy.”


Still another paradigm on the horizon in predictive maintenance consists of not just relying on manufacturers’ standards, but creating a fleet’s own, more tailored, more accurate maintenance approach. This could take into account the nuances and differences in trucking operations, such as truckload versus pickup and delivery.

There is a downside to generalizing assumptions about loose data, including the risk of running up costs and under-estimating the extended life value of some components.

One other critical point is the manner in which information or data is collected and used. The data tracking and analysis must be more sophisticated as the products are achieving longer, more reliable life.

The good news is some industry experts have already developed business analytics programs and reporting designed specifically to maximize the practical value of preventive maintenance data in achieving lowest cost of ownership.


Several truck OEMs are now offering their proprietary software-based systems that facilitate predictive maintenance.

Daimler Trucks North America’s Virtual Technician is an onboard diagnostic system that provides real-time engine diagnostics, enabling drivers and fleet managers to quickly and accurately evaluate events.

According to the company, Virtual Technician helps reduce downtime and decrease maintenance costs by providing a technical snapshot of the engine’s status as soon as the Check Engine light comes on.

When it does, the Detroit Customer Support Center is then notified and it investigates to determine the exact issue, recommended service, how soon the engine needs to be serviced and closest authorized Detroit service location. This information is then relayed to the provided fleet contact.

Once it is decided where the truck will go for service, the support center notifies the service location so it can line up the parts and arrange for service to repair the problem.

“Detroit Virtual Technician combines the best of our resources trained technicians, parts availability, expert call center support and advanced technology - into one package that immediately benefits our customers,” says Brad Williamson, manager, engine and component marketing, Daimler Trucks North America. “With Detroit Virtual Technician, we take the guesswork out of repairs to keep our fleet customers on the road.”


MVASIST is Mack Trucks’ fleet service management platform, offered at no charge to customers who purchase a new Mack.

Launched in 2008, it is a web-based system that allows fleet managers, service providers and dealers to work together in real time to expedite repairs and maximize uptime.

MVASIST allows customers to improve communications, manage costs, reduce downtime and increase operating efficiency, says John Walsh, Mack Trucks’ vice president, marketing. Through an online portal, customers are able to communicate with the dealer, initiate repairs, access a complete service history, approve and monitor repair status and manage repair expenses.

“MVASIST enables timely communication, accurate estimates and access to a complete service history, all in one portal,” he says. It is among the tools the company has developed “to help truck users more efficiently and effectively do their job.”

MVASIST also allows the option of proactively planning and scheduling routine inspections and service. A service advisor can recommend appropriate maintenance, and fleet managers can, at a glance, see the vehicle’s service history.


From the most elementary “just fix it” practice of yesteryear, to the data-driven solutions of today, the entire maintenance process has come such a long way, making vehicles run smoother, longer and more efficiently.

It’s the total cost of ownership (TCO) that matters to fleet owners, and a best practices preventive maintenance approach can move the needle far closer to achieving lowest cost of ownership (LCO).

Take the time to integrate the most advanced business analytics capabilities into your fleet maintenance operations, and the ultimate goal of LCO is one you can achieve.

Dan Umphress is vice president of fleet services for Fleet Advantage. The company serves the leasing needs of Fortune 500 companies and private truck fleets in North America, delivering data-driven fleet management solutions with proprietary information technology and analysis, along with the latest eco-efficient clean diesel technology. Umphress is on the Technology & Maintenance Council’s board of directors and chairs its Study Groups.