Predictive maintenance is still immature on trucks, asserts David Rowlands. He is responsible for the maintenance of 3,500 motive units and 5,000 trailers on the company fleet, and around double that number of assets operated by third parties but maintained by Wincanton’s Pullman workshops.
“On structured contracts where vehicles cover predictable distances, we can call the truck in for service based on what the truck is telling us. Where mileages are not predictable, scheduling is more difficult. It’s easier to service vehicles on a weekly basis,” he adds (although he admits that the operator does use it to monitor in-vehicle oil condition).
Rowlands explains that workshop visits are currently determined by time-based PMIs, from four to 13 weeks. “But as vehicle monitoring systems become more sophisticated, there’s no doubt that we will get more reliant on predictive maintenance. At present, a weekly-based system is easier to plan for, and data from the vehicles is merely an information benefit confirming that the schedule is correct.”
Rowlands regards the technology as being rather fragmented. He says: “We are using it to measure brake pad thickness and tyre pressure, and we are finding benefits, but we really need one holistic solution covering all aspects of the vehicle. Then it will truly be predictive maintenance.”
Some safety-critical aspects are still outside the net. Wheel security and bearing condition are two issues he highlights as not being monitored sufficiently closely yet, along with brake condition and performance beyond lining thickness.
Continues Rowlands: “Ideally, we’d like an [brand-]agnostic system that we can plug into that would give us one view across all makes of truck. The FMS data gateway is currently very limited. We need more data. Truck manufacturers keep too much to themselves at the moment. We would rather have all the protocols available to us. The manufacturers tend to use common systems from suppliers such as WABCO, and we want a standard platform with open access. It’s our data.”
Ultimately though, service scheduling is dominated by operational and legal requirements. Rowlands points out that the first services and annual tests of new vehicles are spread out ahead of what’s actually required – otherwise a tranche of new trucks would all need workshop attention on the same day. Similarly, third parties using Pullman workshops would rather vehicles were serviced early to coincide with PMIs, rather than return to the workshop later for an oil change.
Looking ahead, Rowlands believes that a comprehensive predictive maintenance system that monitors all aspects of vehicle condition will move workshops away from calendar-based servicing and inspections. Annual tests could also be conducted in-house subject to certain rules, he asserts, or even replaced by condition-based PMIs.
But for now, legal requirements, and the need to retain operational capability while ensuring a smooth flow of jobs through the workshops, are more important than pushing service times to the limit of what is sensible or safe.