This is the second part of Debbie Aliya’s blog “Why did the part fail?” Part 1 can be found here.

Failure Analysis as a Process

Performing engineering failure analysis involves a series of activities that unfolds in a flexibly sequential manner. Revealing the damage scenario that led to loss of function requires intentional planning. Describing how the damage occurred involves evaluation of the physical evidence. The physical evidence includes both the actual damaged components and any associated documentation. Human factors tell the story of why the problem arose. These usually have to do with the way the companies involved practice the balance of profit and safety.

By safety, I am implying a broad definition, inclusive of employee and end-user safety, as well as general product durability. This definition of safety may include decisions or practices that may not have any direct effect on personal or public health and wellness.

All of engineering – all of life – may be viewed as balancing the tradeoffs between safety (or risk) and the rest of our activities. Up to a point, it’s safer to stay in bed than to get in a vehicle and go to work or school. It is always possible to make a more robust structure.

But what price is the customer willing to pay? These business decisions may be drawn into the public view as a result of some high-profile engineering investigations. The terrorist attacks that destroyed the World Trade Center in New York in September 2001 were primarily seen as having political roots. Yet 20 years later, humanity is no closer, and perhaps farther, from addressing the conflicts that result in violence. Is that the result of a failure of political scientists or of the way that human affairs are generally conducted?

Failure Analysis as an Engineering Discipline

Engineers perform engineering failure analysis. Failure analysts work within an engineering discipline, not a scientific one. Engineering is based on science but is not identical to it. Many scientists seek knowledge out of pure curiosity. Many scientists say that they are interested in truth. Engineering concerns itself with using the knowledge that scientists or other engineers have revealed. Engineers, as a matter of career-specific ethics, do not need to worry about the ultimate truth of the nature of reality in the same way that theoretical scientists do. The engineer nominally works for human benefit. Engineers happily use empirical knowledge gained in the absence of any theoretical foundations. However, engineers still need to design their products for use in a manner that accords with both the laws of physics and knowledge gleaned through the experiences of their predecessors working in related fields. Engineers need to design products that align with relevant ethical standards.

Humanity benefits when engineers use their knowledge to benefit humanity. Is the backlash against scientific knowledge in the West related to the fact that technological progress and the enlargement of the human population has come at the cost of the rest of Earth’s biome? Of course some of the backlash is related to the same types of reactions that Galileo experienced from the religious organizations hundreds of years ago. Is the backlash today related to the use of technology to create weapons of mass destruction? What is the obligation of the individual engineer to contemplate the effects of her or his work, beyond the effects on a personal bank account?

I have had the chance to work on projects where salvage is being considered for out-of-specification products found before shipment to the customer. Instead of scrapping an entire production lot, I like to encourage salvage when appropriate. Mother Earth has paid the price for the material to be extracted. Energy has been used to make the product. If waste can be avoided without excess risk, salvage may be the right choice. Most specifications are written in a somewhat arbitrary manner. It may be acceptable, on appropriate review, to use out-of-specification parts.