There’s an interesting article by Michael Lam in Overhaul & Maintenance Magazine titled, “The Curious Case of the Irreproducible Result: Demystifying No Fault Found.” (A No Fault Found is an equipment problem reported during ordinary operations that can’t be traced to a specific cause and can’t be reproduced in a controlled environment.) Although written for an aviation audience, this article offers a good overview for any industry trying to reduce the number of No Fault Found (NFF) events.

NFFs are particularly disturbing because they result in so much waste. When a component is replaced unnecessarily, someone must pay for the new part, for the actual service, for scrapping or repairing the old component (and any associated shipping charges), for replenishing inventory, and for the subsequent repair and downtime when the equipment must be fixed a second (or third, or fourth) time. When a component is mis-diagnosed on a plane, train or automobile (or any other piece of complex equipment), it sets off a series of events that impact customer satisfaction, maintenance productivity, and inventory control, all of which harm revenue and profits.

In the aviation industry, 30% of reported faults can’t be reproduced; and, if you focus on avionics—which represent 75% of all aviation NFFs—the number of problems that can’t be reproduced jumps to 50%. The reason, according to Lam, is “the collision of an irresistible force—the ever-increasing sophistication and complexity of aircraft technology (the dense workings of the components themselves, the size and intricacy of the software programs that govern them, and the proliferating interrelationships among various systems and sub-systems)—with an immovable object: the commercial pressures that cap the time available to line maintenance technicians for troubleshooting.” Do dump trucks, locomotives, and control valves experience similar NFF problems? Given the complexity of this equipment, the advanced electronics and automation that is being added, and the harsh environments in which they operate, it would be logical to say “yes”.

Even the incorporation of advanced (and integrated) diagnostics has not solved the NFF problem. Lam says, “Technicians cannot rely on automated test equipment to do their thinking for them. As the NFF rate shows, they’re not sufficiently reliable. The best corrective is a better understanding of the underlying mechanisms and their interconnections.” In other words, the answer to reducing No Fault Found events is not more automation but rather better information. The article advocates that companies adopt a holistic approach to diagnostics, fault isolation and resolution—all of which is predicated on a more complete understanding of the equipment and the operating environment.

I agree with Lam’s assessment and Enigma has always stressed the importance of providing complete and relevant information to maintenance planners, engineers and parts managers. Whether it’s parts catalogs, service manuals or proprietary maintenance techniques, Enigma supplies all the information necessary to accelerate troubleshooting, streamline repairs and improve maintenance quality. For further reading on aviation NFFs, please see ARINC Report 431: No Fault Found – A Case Study and ARINC Report 672: Guidelines for the Reduction of No Fault Found. No Fault Found is a critically important topic for any company with aftermarket operations; therefore I will post more information as I find it.