Dealing with Failures that Destroy
Kirk and Fred discussing the challenge of understanding the root cause of failures for products that are hard to retrieve from the field or have other reasons that make failure analysis almost impossible.
Join Kirk and Fred as they discuss different situations and conditions where the products failure analysis can’t be done after its failure in the field
- Some products have self destruct mechanisms to prevent fraud in a secure system which prevents tampering but also prevents failure analysis
- Weapon or ordinance that fails to detonate in the field is generally still very dangerous and not worth risking retrieval and analysis
- Isolation of subsystems or components and measuring the most likely driving mechanism progressing the product to failure using potential causes through fault tree analysis.
- Safety or thermal shutdown interlocks are limitations have to be disabled during HALT. In HALT the goal is finding the designs operational limits and not preset trigger points to protect itself or others in the field from damage.
- In some cases replacing a component destroyed in a HALT evaluation to a higher power component can improve reliability without knowing the complete root cause of the destroyed device.
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.
Click on this link to access the article from the US ARMY and CALCE titled “Reliability Prediction – A Continued Reliance on a Misleading Approach”
For more information on the newest discovery testing methodology here is a link to the book “Next Generation HALT and HASS: Robust design of Electronics and Systems” written by Kirk Gray and John Paschkewitz.
Oleg Ivanov says
This is a very interesting research topic. I would also add failure masking. When one failure leads to the destruction of the product and does not allow the manifestation of another more dangerous failure in HALT.
Kirk Gray says
Thanks Oleg for your comment, I agree and that is why we need to have to use multiple samples for each HALT.
Oleg Ivanov says
Hi Kirk. I’m afraid on each sample, the first failure will mask the second failure. Another way is to search for such HALT modes to exclude masking of failures.