Category Archives: MTBF

Mean Time Between Failures or MTBF is a common metric for reliability and is often misused or misunderstood.

NoMTBF Non-Users Group

Let’s Create a NoMTBF Non-User’s Group Today

We do it right!

Those that read this blog regularly know that I, along with many others, have some passion for the eradication of MTBF from common use. We make arguments, create examples, describe the errors and encourage using other methods. The campaign seems to be going along well. Yet MTBF is still in use – in standards, in certifications, and even taught by those that should really know better. We’re making progress, but there is much more yet to do. Continue reading NoMTBF Non-Users Group

Please don’t remove MTBF, part 2

Please don’t remove MTBF, part 2

This note is the second part of my response to a forum entry by HL concerning two arguments he is attempting to refute. Of course, my arguments for the eradication of MTBF may stir up some resistance. My plea to use a better approach may challenge the status quo or ruffle a few feathers. So be it. That is expected. Continue reading Please don’t remove MTBF, part 2

MTBF: What is it Good For?

MTBF: What is it Good For?

Guest post by Andrew Rowland, CRE, ReliaQual Associates, LLC

I.  INTRODUCTION

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?

difference between average and actual

Where MTBF falls short

Where MTBF Falls Short

 Guest post by Chris Peterson – see her daily blog Test To Be Your Best

I have a brand new widget and I’m very excited about the design.  It has features I’ve never built in before, there is a huge market need for it, and now I have to try to prove it’s reliability before I can sell it.  What do I use? Continue reading Where MTBF falls short
White ceramic mug with NoMTBF logo

NoMTBF guest post Challenge

In the NoMTBF newsletter I’ve announced a contest for this site.

I’d like to invite you to write a guest post on MTBF, either good or bad, for or against, a case study or how-to-use article. Just something about MTBF.mug

Then, if during the week we post it the site reaches a new record for visits, I’ll send you a shiny new NoMTBF logo coffee mug. Continue reading NoMTBF guest post Challenge

MTBF Leadership

MTBF Leadership

MTBF is a common reliability metric. It is totally useless in most applications. So, why do we use it? And what can we do as reliability professionals to lead our industries away from using MTBF?

A recent set of forum discussions raised the idea that we use MTBF because our customers require it. Another writer suggested that MTBF is useful because it has been in use for so long, and therefore it must be useful. Another writer advertised their offer to determine MTBF for you for a small charge. Continue reading MTBF Leadership

Weibull vs Exponential PDFs

Comparison of Weibull vs Exponential PDFs

This is a short interactive note that let’s you play with different β values and compare the impact for a simple calculation. You may need to download and install the free Wolfram Player and plugin for your browser. You can find it at

<http://www.wolfram.com/cdf-player/

Continue reading Weibull vs Exponential PDFs

Value and MTBF

2008-04-28 RockClimbingValue and MTBF

The value of any task is in the result, although a few may argue about the value in the journey itself. For reliability engineering tasks, the ability to use the output of an experiment or analysis to make decisions permits an organization to derive value from the tasks. Despite a few organizations that insist on Continue reading Value and MTBF

Change from MTBF

If you want to make enemies, try to change something ~Woodrow Wilson

Change

Newton had it right, objects at rest tend to remain at rest, and objects in motion tend to stay in motion. We can say that both states resist changing into the other state unless some force acts on the object. You can feel this resistance when going around a corner in a car. You body seems to want to continue straight and it is the seat, belt buckle, door frame that conspire to bring you along with the car around the corner. Continue reading Change from MTBF

Just muttering MTBF

Anyone that knows me understands that even muttering MTBF in a conversation or even in passing will generally set me off on a anti MTBF tirade. My better friends tend to avoid the topic altogether. And those that are curious about ‘why’ will ask me. In the process I hope to help you think about MTBF and the many issues around its use, and to make or improve friendships. Continue reading Just muttering MTBF