RM 197: Closing the Gap Between Validation and Reality

Mike Konrad (0:00)

What if passing the test is not enough? In reliability engineering, we often place a great deal of confidence in laboratory validation. We test, measure, analyze, and document. And when the product passes, we naturally assume it's ready for the field. But what happens when a product passes the lab test and still fails in the hands of the customer? Welcome or hopefully welcome back to Reliability Matters. I'm Mike Konrad.

Today, we're going to explore the gap between laboratory reliability testing and actual field performance. It is a gap that can be costly, frustrating, and sometimes difficult to explain. Products can perform well under controlled test conditions, yet still experience unexpected failures when exposed to real users, real environments, real service conditions, and real world variability.

My guest today is Dr. Nishith Kumar Reddy Gorla of Core Its Llc. Dr. Gorla's work focuses on systems-level reliability testing, field reliability alignment, reliability growth, and test-to-field correlation for complex products. His recent paper, System Level Test Case Design for Field Reliability Alignment in Complex Products, that's a mouthful, looks at why functional reliability test methods may miss important field failure modes. More importantly, he proposes a broader approach to test case design that considers not just the product design, but also actual use conditions, field failure data, end user behavior, service procedures, manufacturing variation, consumables, and product interfaces. This is an important conversation because reliability is not simply about passing a test. It's about understanding how a product behaves in the real world, where variables interact, users behave unpredictably, environments change, and failure mechanisms may not appear until the system is challenged in realistic ways.

If you design, build, test, specify, or depend on complex products, this discussion should be especially relevant. Today, we'll talk about why products sometimes pass in the lab but fail in the field, how better system-level test cases can improve field correlation, and what reliability professionals can do to create test methods that more accurately reflect real-world performance. And it all begins right now. Stick around. This is going to be good.

SPEAKER_2 (2:27)

Welcome to Reliability Matters, a podcast for the electronic assembly industry. Each episode covers topics related to reliability, best practices, and environmentally responsible assembly techniques. With insights from experts across the electronic assembly industry. Now, here's your host, Mike Konrad.

Mike Konrad (2:46)

Nishith, welcome to Reliability Matters. I'm happy to have you here today.

Nishith Kumar Reddy Gorla (2:51)

I'm pleased to participate in this podcast. So it was a nice introduction as well.

Mike Konrad (2:58)

Well, you have a lot of nice work you've done.

And this particular topic is perfect for the show, because reliability often somewhere in there is testing and reliability assurance, not reliability assumptions, reliability assurance. And sometimes it becomes assumptions. So we're going to talk about that. Before we get into the technical details of all this, can you tell us about your background and how you became focused on reliability engineering and system level test design? How did you get here?

Nishith Kumar Reddy Gorla (3:33)

So actually, my background is a little different than reliability. So I have my doctoral degree in aerospace engineering from University of Texas at Arlington. Then I was looking for opportunities to move to aerospace background. Then I had a little, you know, tough time or challenging days getting to the aerospace field. Then I was looking like what would be the next, you know, future step I would like to take, which will align with my, you know, background and those things. Then I somehow I started interested in medical devices. Then I was joined as a verification and validation engineer. So then I was more interested in reliability and stuff. Then I get into the reliability work. Then it was a new product development, the stage, I mean, in the, during the initial days, it was nothing in our company on the reliability. Then when I joined, we started a reliability testing, creating from the reliability goal, from the reliability plan to all DFR processes.

I was more focusing on how we design the test, and how we design the test case. Those things are very critical in the reliability field. So then we should have an approach. Otherwise, if you want to test some random failure for anything else, then we don't know whether it's going to happen in the field or not.

It should be realistic.

Then we created an approach for the reliability test design. So, it seems for example, right? So, if you have, if you take motor, ASE motor is an example. So, you have n number of failure modes. You don't know like which one to test, right? So, we earlier, we have a, like earlier we had traditional approaches, like based on the expert opinion, or follow the military handbooks, or any kind of standard. So, we refer to those handbooks, and then we document failure modes, and then we move forward. But how this is realistic for, so the products may be different. I mean, you can see the similar components or similar parts from different handbooks and those things, but how it will be suitable to your actual product or application. That is the matter, right?