Regardless of the outcome, I believe we can learn from the event as it has unfolded. We know that according to the original Nowlan and Heap study, which became the foundation of Reliability Centered Maintenance, that 69 percent of the failure modes within our facilities or on our airplanes can be categorized as infant mortality. We also know that many of us, including myself in the early days, look to redesign as the first solution to many problems before truly understanding all of the root causes. If we put the two together then we can likely expect that if we use solely a redesign strategy then the introduction of more failure modes and more infant mortality is a given. When we redesign to remove one known failure mode we stand a very good chance of adding many more unknown failure modes if we are not using a tool like Failure Modes and Effects Analysis or FMEA. When we redesign we very seldom make things simpler and therefor the more complex redesign comes with more points of failure. So please understand redesign is a valid solution but it should not be your go to solution within most facilities. In the spirit of wrapping it up the three take always from today's post are:
- Use root cause and don't be afraid of short term solutions but always have a long term plan for defect elimination or mitigation at the systemic and latent levels based on return on investment and risk thresholds.
- Redesign should not be your first choice in most failure investigations. Infant mortality and unknown failure abound in redesign decisions.
- Third if you are a root cause practitioner then you can not give in to speculation and rumors without data. Lets leave those to the tabloids and non fact based news outlets of which we have plenty.
"History teaches us that all new aircraft types have issues, and the 787 is no different," Smisek said. "We continue to have confidence in the aircraft and in Boeing's ability to fix the issues, just as they have done on every other new aircraft model they've produced."
Designers and Re-designers must expect infant mortality and use tools like RCM, FMEA, and RCA to mitigate these problems and the risk that associate with them. What are you doing to reduce infant mortality in your plant?