A short video discussing the importance to engineering test data analysis of confidence intervals.
[Read more…]Why is Confidence Level so Important in Engineering Test Data Analysis
on Product Reliability
A listing in reverse chronological order of articles by:
- Kirk Grey — Accelerated Reliability series
- Les Warrington — Achieving the Benefits of Reliability series
- Adam Bahret — Apex Ridge series
- Michael Pfeifer — Metals Engineering and Product Reliability series
- Fred Schenkelberg — Musings on Reliability and Maintenance series
- Arthur Hart — Reliability Engineering Insights series
- Chris Jackson — Reliability in Emerging Technology series
FMEA or RCA?
Probably every engineer has heard once in his experience terms FMEA and RCA.
What is FMEA?
FMEA is a systematic method for identifying and preventing potential failure modes in a product or process. It helps in proactively addressing failure risks, improving reliability, and enhancing safety. FMEA is crucial in various industries, including automotive, aerospace, and manufacturing, to ensure product quality and customer satisfaction.
[Read more…]What is the job of a Validation Engineer?
Once upon a time in my former life, I served as the Quality Manager for a $300M tier-one automotive manufacturing plant that provided components and assemblies to OEM vehicle assembly plants. You would recognize our customers – most of the big names. This assignment was a departure from my previous roles in product development and testing. To say that the job was eye-opening is an understatement. Years later, I described this three-year experience to friends as my “tour of duty on the front lines.” Anyone who has spent any time in manufacturing can certainly relate!
Hypotheses Testing – What is That?
Well, this article will be a little bit challenging and full of statistical terms. I would categorize the “Hypothesis testing” as most of common use in statistical analysis.
First time of usage happened in 1700s, but actual popularisation at early 20th century:
[Read more…]Test Design for Component Life
Why make a Histogram graph?
Background:
A histogram – is an approximate representation of the distribution of numerical data. The term was first introduced by Karl Pearson:
[Read more…]Introduction to the t-test
A brief introduction to the statistical hypothesis test called the t-test. Useful when examining if there is a difference between the means of two groups.
[Read more…]Why is Confidence Level
Why is confidence level so important in engineering test data analysis?
From the name itself it gives us a very good hint; Confidence level is giving the confidence in data analysis. In the next graph, you can find 10 samples and fitted Weibull 2p distribution with 95% of Confidence level:
[Read more…]Boeing, Boeing, … Bugger. Now it’s the Starliner
There might not ever be a better demonstration of the saying that …
… a fish rots from it’s head.
Boeing is responsible for the half-baked Maneuvering Characteristics Augmentation System (MCAS) that was forced into its new 737 Max aircraft. This involved a decidedly awful attempt to convince the Federal Aviation Administration (FAA) that there was no need to subject said aircraft through all the checks and balances that you need to go through if it is in fact a brand-new and different type of plane. Which it was. This resulted in the deaths of 346 passengers and crew (along with plenty of claims that it was pilot error). And just to be clear, Boeing has since admitted that it’s employees defrauded the FAA during the original certification process – an admission it was not required to make if it was able to complete a three-year period of increased monitoring and reporting. Which it could not.
[Read more…]HALT or ALT
Exploring the differences between HALT and ALT, or Highly Accelerated Life Test and Accelerated Life Test. Plus when to use which when.
[Read more…]Reliability vs. Durability
It seems a big misconception in different industries between those two terms “Reliability” and “Durability”. So, first thing first, I apply google research to find out what is definitions:
Reliability is defined as the probability that a product, system, or service will perform its intended function adequately for a specified period of time or will operate in a defined environment without failure. (Source American Society for Quality (ASQ))
Durability is the ability of a physical product to remain functional, without requiring excessive maintenance or repair, when faced with the challenges of normal operation over its design lifetime. (Source Wikipedia)
[Read more…]How to not Suck at Probability and Statistics
A simple way of looking at our brain is by dividing it into the conscious, subconscious and unconscious minds. The conscious mind is all about what we are actively thinking about in the here and now. We might be navigating as we drive through the countryside. We might decide to take an exit from the main road because our conscious mind has worked out that the map we are looking at is showing us that’s what we need to do to get to where we want to go.
ALT or Durability Test?
A brief discussion on the difference and similarities of accelerated life testing (ALT) and durability testing. For one difference, ALT used high stress conditions to shorten the time to failure. Whereas, durability testing typically uses whole products and normal use condition.
[Read more…]Normal Distribution in Reliability Analysis
Normal distribution is most common in real life scenarios be it modeling any reliability performance parameter at a specific time. Central Limit Theorem (CLT) shows why normal distribution occurs so often.
[Read more…]Always Looking for Someone to ‘Sign Off on That? … Your Organization is Probably Struggling
When I was a bright eyed, motivated (younger) officer in the Australian Army, one my many tasks when deployed overseas was to raise paperwork to formally request ‘battlefield material’ to be sent back home from whatever country we were in. ‘Battlefield material’ was items that included a range of mementos, keepsakes, and things you would typically see in a museum to add to the historical collections of my battalions and regiments back home.
