A Guest Post by Jim McLeish titled:
Replacing MTBF/MTTF with Bx/Lx Reliability Metrics
Jim McLeish – Mid-West Regional Manager – DfR Solutions
(Rochester Hills Michigan)
Expanded from the RIAC Reliability Information Analysis Center Linkedin Group Discussion on
“Great challenge for change from Fred – No MTBF!”
“Endless discussion and it seems there’s no real solution to get rid of MTBF”
See original and ongoing Linkedin discussion here.
I am absolutely astonished that the reliability profession and its noted experts are unable to develop a better metric to characterize reliability performance and specify reliability requirements. I respectfully submit that there is a simple and eloquent solution that has successfully been used in the ball bearing and machine industry for decades (that actually predates MTBF/MTTF), that should be considered as a replacement to MTBF/MTTF. Continue reading Replacing MTBF with Bx →
MTBF: What is it Good For?
The mean time between failure (MTBF) is arguably the most prolific metric in the field of reliability engineering. The MTBF is used as a metric throughout a product’s life-cycle; from requirements, to validation, to operational assessment. Unfortunately, MTBF alone doesn’t tell us too much. Continue reading MTBF: What is it Good For? →
This post is a conversation first held on the LinkedIn group No MTBF. I’m capturing a portion of the contributions here to continue the discussion or to widen the audience. Reminds me of always assuming 95% confidence is the right value when designing a test, or assuming constant failure rate. So, let the conversation continue, starting with the original post. Continue reading Where does 0.7eV come from →
Most of us have seen reliability specified using a requirement like the following:
The Zeus 5000 SUV shall have an MTBF of 144,269.5 miles with a 90% confidence.
Some readers may not have seen reliability requirements specified in any other way. What they have always seen has read something like: The widget shall have an MTBF of X with a Y% confidence. This reliability requirement structure is rather ubiquitous Continue reading The Worst Reliability Requirement →
Most reliability engineers are familiar with the life cycle bathtub curve, the shape of the hazard rate or risks of failure of a electronic product over time. A typical electronic’s life cycle bathtub curve is shown in figure 1. Continue reading Why The Drain in the Bathtub Curve Matters →