Behind the Scenes at DTNA's Testing Program

What has seemed like an almost flawless launch for the Detroit Diesel DD13/15/16 has likely been because of the Reliability Growth testing, started back in 2005 at Daimler Trucks North America's new facility in Portland, Ore.

The function of this group is to hammer new products with the harshest "real-world" conditions the engineers can find. Any faults discovered are identified, allocated, addressed and validated before the issue gets taken off the board.

As each emissions mandate has resulted in revamped or entirely new engine models, one big question on everyone's mind has been reliability. In some previous emissions changeovers, many believe, engine makers did not have a chance to do enough rigorous testing to ensure reliability.

But DTNA's Reliability Growth program, as its name implies, is all about triggering faults in soon-to-be introduced products as well as in current models by punishing them at high gross weights over the mountains of the Pacific Northwest. At the new Swan Island offices and shop - only a minute away from Freightliner's headquarters and most of its engineering staff - another group of engineers, along with technicians and drivers, beat the living daylights out of around 40 trucks. They're mostly Freightliner Cascadias, with a smattering of Western Star, Mercedes-Benz cabover Actros, and even a lone Fuso from Japan.

Engines in the mix are Detroit Diesels from the Heavy Duty Engine Platform (HDEP) newly introduced with the DD15 in late 2007, as well as the Cummins ISX. Fortunately for the program, there's a Cummins facility right next door so the Reliability Growth team can lay problems right at their door if an issue with the ISX is discovered.

Detroit Diesel, of course, is back in Detroit, but on-site in Portland is a team of seven engineers under Andreas Juretzka tasked with finding faults, tagging them with the engineer responsible for a solution and then following through to ensure the problem doesn't show up in the field.

The trucks run on a number of reliability routes, most in the Oregon mountains or on the busy city streets of Portland. Running high gross weights - 105,000-pound GCW Rocky Mountain doubles and 130,000-pound lowboys - in these deliberately demanding conditions, the team is out to create problems in the truck systems. Gone are the days when you could test components on the bench. Now it's all about the truck systems. That's why Cummins is in the program. As Engineering Chief Elmar Bockenhoff - the creator of the Reliability Growth concept - says, the logo is on the front of the truck and the customer expects the company to stand behind its products.

You may think, that's nothing unusual - testing is part and parcel of developing any new product. But what is different at DTNA's Reliability Growth operation is a very strict procedure in the collection of anything that could be regarded as a fault, then a rigorous process of assigning the issue to the engineers responsible; tracking the progress of fixing it; then, critically, validating that the fault will never return in the life of the production trucks. In the case of the Detroit Diesel engines, Juretzka is on site for the testing and any issues are tracked by his team back through Detroit.

The eight-point process is completed by the validation step, the ongoing testing up and down the mountains to ensure that the issue has been addressed with a satisfactory solution and that it won't show up again.

The reliability team is lead by Al Pearson, newly appointed chief engineer, Product Validation Engineering. Pearson says the program really works. They see it in the improved reliability and durability numbers. In an aside, Pearson mentioned that the considerable expense of running this operation - unique among North American manufacturers - shows up with a significant multiplier as savings in warranty costs.

But it also saves the customer from the unscheduled downtime that can be so difficult for the end customer to manage. That, says Bockenhoff, is the true payoff.