We see the terms ‘reliable’ and ‘reliability’ in daily advertising, business names and in casual conversations on a regular basis. Reliability has meaning and importance in our society. Product and brand reputations are made or broken by their product reliability performance.
Archives for August 2014
Censored Data and CDF Plotting Points
Reliability testing and data collection is a messy business.
We rarely receive perfect data where all units involved have a precise time to failure record. Sometimes we do not the precise time to failure information or some of the units are still operating.
The data is censored.
There are a few common types of censoring, each of which has statistical techniques to appropriately account for the unknown elements. [Read more…]
How to Assess Your Reliability Program
“How do you know so much about our program?” was a question the quality manager asked after reading the assessment report. The assessment took one day with eight interviews.
The reliability that results is going to happen whether or not the team designing the product or production line deliberately use reliability engineering tools or not. The elements of a product or system will respond to the environment and either work or fail.
While working at Hewlett-Packard I had the opportunity to conduct reliability program assessment of about 50 product divisions. One hypothesis related the number of reliability tasks the team actively used would correlate to their warranty expenses.
That worked to a point. [Read more…]
4 Electronics Nondestructive Evaluations
It is possible to use the circuit design or the circuit itself to evaluate electronics. This ranges from checking if the system is wired correctly (the right parts are present and attached properly) to a complex evaluation including the proper functioning of firmware and attached software.
Beyond visual inspection, we need a way to evaluate the microscopic structures with today’s electronic components.
The ability to provide inputs and measure outputs provides one view and in most cases is nondestructive. [Read more…]