Math, Statistics, and Engineering

14586673050_b71972cc74_m_dMath, Statistics, and Engineering

In college, Mechanics was a required class from the civil engineering department. This included differential equation.

Luckily for me, I also enjoyed a required course called analytical mechanics for my physics degree. This included using Lagrange and Hamiltonian equations to derived a wide range of formulas to solve mechanisms problems.

In the civil engineering course, the professor did the derivation as the course lectures, then expected us to use the right formula to solve a problem. He even gave us a ‘cheat sheet’ with an assortment of derived equations. We just had to identify which equation to use for a particular problem and ‘plug-and-chug’ or just work out the math. It was boring. Continue reading “Math, Statistics, and Engineering”

What’s All the Fuss about Bayesian Reliability Analysis?

The term Bayesian Reliability Analysis is popping up more and more frequently in the reliability and risk world.  Most veteran reliability engineers just roll their eyes at the term.  Most new reliability engineers dread the thought of having to learn something else new, just when they are getting settled in the job.  Regardless, it is a really good idea for all reliability engineers to have a basic understanding of Bayesian Reliability Analysis.

This series explains Bayesian Reliability Analysis and justifies Continue reading “What’s All the Fuss about Bayesian Reliability Analysis?”

Use the right fit

I’ve often railed on and on about the inappropriate use of MTBF over Reliability. The often cited rationale is, “it simpler”. And, I agree, making simplifications is often required for any engineering analysis.

It goes to far when there isn’t any reason to knowingly simply when the results are misleading, inaccurate or simply wrong. The cost of making a poor decision based on faulty analysis is inexcusable. Continue reading “Use the right fit”

MTBF free Availability

The classic formula for availability is MTBF divided by MTBF plus MTTF. Standard. And pretty much wrong most of the time.

Recently working for a bottling plant design team we pursued the design options to improve availability and throughput of the new line. The equipment would remain basically the same, filler, capper, labeler, etc. So we decided to gather the last 6 months or so of operating data which included up and down time. Furthermore the data included time to failure and time to repair information. Continue reading “MTBF free Availability”