No MTBF Blog

A site devoted to the eradication of MTBF. The following excepts are recent posts of the

NoMTBF blog. Click through or visit nomtbf.com to learn more about the perils and what you can do instead of using MTBF.

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  • A Series of Unfortunate MTBF Assumptions
    A Series of Unfortunate MTBF Assumptions The calculation of MTBF results in a larger number if we make a series of MTBF assumptions. We just need more time in the operating hours and fewer failures in …
  • Time to Update the Reliability Metric Book
    It is Time to Update the Reliability Metric Book with Your Help Let’s think of this as a crowdsourced project. The first version of this book is a compilation of NoMTBF.com articles. It lays out why w …
  • We Need to Try Harder to Avoid MTBF
    We Need to Try Harder to Avoid MTBF Just back from the Reliability and Maintainability Symposium and not happy. While there are signs, a proudly worn button, regular mentions of progress and support, …
  • 3 Ways to Expose MTBF Problems
    3 Ways to Expose MTBF Problems MTBF use and thinking is still rampant. It affects how our peers and colleagues approach solving problems. There is a full range of problems that come from using MTBF, y …
  • The Army Memo to Stop Using Mil HDBK 217
    The Army Memo to Stop Using Mil HDBK 217 Over 20 years ago the Assistant Secretary of the Army directed the Army to not use MIL HBK 217 in a request for proposals, even for guidance. Exceptions, by wa …
  • Why do we use Weibull++ over JMP?
    Why do we use ReliaSoft instead of JMP to Identify the Time to Failure? This is a question someone posted to Quora and the system prompted me to answer it, which I did. This question is part of the ge …
  • Futility of Using MTBF to Design an ALT
    Futility of Using MTBF to Design an ALT Let’s say we want to characterize the reliability performance of a vendor’s device. We’re considering including the device within our system, if and only if, it …
  • Two Ways to Think and Talk about Reliability
    Two Ways to Think and Talk about Reliability Neither includes using MTBF, btw. And, I’m not thinking about the common language definition either. Plus, I may have this all wrong. Here is the way I thi …
  • The Damage Done by Drenick’s Theorem
    The Damage Done by Drenick’s Theorem Have you ever wondered by we use the assumption of a constant failure rate? Or considered why we assume our system is ‘in the flat part of the curve [bathtub curve …
  • 3 MTBF Stories
    3 MTBF Stories Everyone loves a great story. Storytelling has been a long tradition to pass along knowledge and wisdom. There are good stories, tales of inspiration. There are sad stories, tales of ca …
  • Different Data Same Decision
    Different Data Same Decision Let say you have some time to failure data on your equipment. A common action is to calculate the MTBF. All well and good until you expect to make a meaningful decision ba …
  • 5 Reasons Rate of Change is Important
    5 Reasons Rate of Change is Important A simplifying assumption associated with using MTTF or MTBF implies a constant hazard rate. Some assume we’re in the useful life section of the bathtub curve. Oth …
  • How About Weibull Instead of MTBF?
    What About Weibull, Can I Use it Instead of MTBF? This was a follow up question in a recent discussion with Alaa concerning using a metric other than MTBF. The term ‘Weibull’ in some ways has become a …
  • Are We Teaching Reliability All Wrong?
    Let’s Demand Better Reliability Engineering Content Teaching reliability occurs through textbooks, technical papers, peers, mentors, and courses. The many sources available tend to use MTBF as a prima …
  • Life Data Analysis with only 2 Failures
    Life Data Analysis with only 2 Failures Here’s a common problem. You have been tasked to peer into the future to predict when the next failure will occur. Predictions are tough. One way to approach th …
If you’d like to learn more about MTBF and how to improve your reliability metrics, let’s talk.