Minor Changes, Major Consequences

Even small differences in components or materials can result in unforeseen problems

Published: Monday, January 11, 2016 - 17:46

My article, “Change and Risk-Based Thinking” describes management of change (MOC) as a safety-related phrase from the chemical process industry. MOC says that anything new, different, or nonroutine (such as repairs, equipment replacement, and process startups) creates a safety risk, but the same principle also applies to quality risks.

This concept is detailed in “Recognize Hazards to Recognize Change,” an article by Donald K. Lorenzo, Della Wong, and Mark Suyama in the April 2015 issue of Chemical Engineering Progress. Any change in any of the traditional cause-and-effect diagram categories (e.g., manpower, method, material, machine, measurement, and environment) entails the risk of unforeseen and unintended consequences. This is particularly true with supplied materials.

Gerald Kersh’s 1953 science fiction story, “Whatever Happened to Corporal Cuckoo?” features a protagonist whose wounds the French surgeon Ambroise Paré treated with a Roman concoction of oil of roses, turpentine, and egg whites. This not only healed his wounds but also made his body able to regenerate itself despite massive injuries and rendered him immortal in the bargain. He spent the next centuries in futile attempts to recreate Paré’s formula, only to learn that his reaction to the mix might have been entirely due to specific characteristics of the roses and/or eggs that the surgeon had used.

This issue isn’t limited to the realm of science fiction. The article, “Re-Creative Successes: Tales of ancient recipes being carried out in modern-day laboratories” by Sarah Everts, which appeared in the Aug. 3, 2015, issue of Chemical & Engineering News, describes historian Lawrence Principe’s initially unsuccessful attempt to create glass of antimony despite conforming exactly to an alchemical reference. The recipe specified stibnite (antimony sulfide), but Principe obtained gray lumps rather than yellow glass when he followed it. The problem was that the original alchemist had used stibnite from Eastern Europe, where the ore contains 1 to 3 percent silica. The absence of this minor ingredient, which was not even specified, was why the results were not reproducible.

Principe’s attempt to reproduce Bologna stone by following an alchemical recipe to the letter was equally unsuccessful. The formula called for barite (barium sulfate), but it did not deliver the impressive phosphorescent minerals that appear in a Google image search for “Bologna stone.” Principe discovered that the barite did, in fact, have to come from Bologna because that particular mineral is first, free of iron, which shuts down luminescence; and second, contains trace copper, which is necessary for luminescence. The ancient “specifications” didn’t even mention iron or copper despite their importance.

The article also describes the rediscovery of an anti-malaria drug from an ancient Chinese manuscript. Initial attempts to reproduce it didn’t work when the researchers tried to extract it by boiling sweet wormwood. Then they realized that the manuscript had said to soak the leaves in cold water, and that boiling might destroy the active ingredient. Use of ether as a solvent worked equally well, and the resulting product, artemisinin, was successful against malaria. In this case, an unintentional change in the process rather than the material was the issue.

I recall a situation in which a purportedly minor change to a photoresist for semiconductor manufacture caused serious trouble for my employer’s processes, even though other customers didn’t notice any difference. Common sense says that one does not cut corners by substituting a cheaper and inferior material or component, but since product substitution is illegal in federal contracts, it’s also unacceptable to substitute a more expensive, and purportedly superior, material or component without the government’s consent. The reason is almost certainly that, despite the supplier’s intention to deliver more value for the customer’s money, the unauthorized change could create unforeseen risks.

It is therefore vital to review any change in supplied components or materials to ensure that even seemingly minor or trivial differences do not result in major problems.

About The Author

William A. Levinson

William A. Levinson, P.E., FASQ, CQE, CMQOE, is the principal of Levinson Productivity Systems P.C. and the author of the book The Expanded and Annotated My Life and Work: Henry Ford’s Universal Code for World-Class Success (Productivity Press, 2013).