Good Reliability Testing
Abstract
Chris and Fred discuss the difference between good and poor reliability testing.
Key Points
Join Chris and Fred as they discuss what makes a meaningful and valuable reliability test. And more importantly, how to use test results to make valuable decisions. And to make a decision – you need to read the reports!
Topics include:
- Leadership needs to be bought in. There are plenty of really good tests where for whatever reason, the leadership team won’t read (or believe) the reports. NASA did this when they disregarded reports that suggested that detaching foam insulation couldn’t damage the wings of the space shuttle (which is precisely what happened in the 2003 Columbia disaster). And then there are leadership groups that give reliability engineers two data points and then want to demonstrate that the item will have a 99 % chance of lasting 20 years.
- And it matters ‘when’ you do testing. Most militaries focus on receiving ‘production ready’ tanks, planes, and weapon platforms after years and millions of dollars of development to be subjected to ‘acceptance testing.’ This ‘acceptance testing’ can often be exhaustive, involve lots of data points … but because it is done after the production process is complete, if the item fails the test, there is no feasible way of walking away from buying that item. There is no time or money left to do anything to improve the design, so the test results get ‘doctored’ or data points are explained away with minor corrective actions so that the fundamentally unchanged item is now deemed reliable enough. Pointless.
- There needs to be a strategy … tied to a decision. If at test doesn’t influence a decision, then don’t do it. If you are going to accept an item regardless of how it performs on the test … don’t do it. If you are going to conduct HALT testing, but the boss will never read the report … don’t do it. Work out what decisions you need to inform, work out if there is a test that can help, and only then implement that test.
- And when it comes to reliability … nothing beats actually understanding ‘how’ your thing fails. If you are a reliability engineer who only gains confidence based on data points in a spreadsheet, then you are not a ‘good’ reliability engineer!
Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches.
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