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October 1, 2008 Vol. 1, Issue 9


In the spirit of NASA’s fiftieth anniversary, ASK the Academy looks back forty years to a letter written by George S. Trimble, Deputy Director of the Manned Spacecraft Center (now Johnson Space Center) from 1967-1969, on the definition of systems engineering.

Trimble’s skeptical, humorous letter was reprinted in “Readings in Systems Engineering,” a 1993 anthology edited by Francis T. Hoban and William M. Lawbaugh (NASA SP-6102). The text and editors’ note below appear verbatim as printed in that volume.

Defining Systems Engineering
by George S. Trimble

Editors’ Note: Back on September 27, 1968, a NASA engineer by the name of George S. Trimble wrote to the Chief of the Management Analysis and University Programs Office after the Chief issued a letter to find a universally suitable definition for “systems engineer.” The engineer told the manager that the term had no particular meaning at all. “In fact,” Trimble claimed, “I may know the guy who thought it up or resurrected it, as the case may be, for modern usage.” His seemingly authoritative account follows:

During the war, new management practices were introduced at a great rate, and one of the functions that came to the fore was the business of writing job descriptions and evaluating them. Certain industrial relations experts fell heir to this function, and there was a tendency for them to write very clear job descriptions for all jobs except their own. It soon became obvious that the value of a job, or, more importantly, the money it paid (or even more importantly, its draft-dodging power), was inversely proportional to the ease with which one could describe it. Industrial relations people were able to describe any engineering job in 25 words or less, whereas an industrial relations function might take two or three pages. Miserable to begin with, engineering salaries were further threatened and so was draft status.

Of course, everyone knows that engineers are very creative. They could see that the industrial relations boys had a good thing going, so they borrowed the approach and improved on it (typical engineering method).

Soon it took five pages to describe the most menial engineering task, and the engineers were saved. It was a simple matter to spend three hours explaining to a job analyst from industrial relations why a ‘systems engineering’ blueprint file was much more complicated to run than a simple old ‘engineering’ blueprint file, which was, of course, familiar. The guy from industrial relations never did understand it because the guy who explained it didn’t. It takes a lot of words to explain something you don’t understand or that isn’t there. Try explaining ‘zero’ sometime.

A parallel effort with the objective of emphasizing *!!ENGINEERING!!* was carried out with great dispatch by the ‘scientists,’ all of whom became famous at the close of WWII because a couple of them invented and built the A-bomb, all by themselves, with great secrecy. What they were really doing all that time, of course, wasn’t science — it was engineering. When this was discovered, a mixed wave of nausea and terror ran through the brotherhood. It was worse than being caught reading a dirty book in church. Most learned scientists knew that engineers were people who ran around with special hats and oil cans and made steam locomotives go, and who, incidentally, made too much money. Being identified as part of the same crowd was too much for the intellectuals to bear. Scientists had to be working on something more important than ‘engineering’, which is supervised by a Ph.D and is therefore high-class and also obvious to those schooled properly, but difficult if not impossible for anybody else to understand.

Since, as we all know, very few, if any, Ph.Ds understand the meaning of plain, ordinary ‘engineering’, it follows that ‘systems engineering’ has given engineering a bad name, and should be avoided for that reason alone.

A third group who helped the cause for systems engineering were the pre-war ‘handbook’ engineers who discovered creative engineering when they joined up with a wartime industrial engineering group to avoid being drafted. They had always thought that engineering was the choosing from a catalog of the proper washer for a quarter-inch bolt. It was difficult for them to use the same name for their new discovery, creative engineering (designing a washer for a quarter-inch bolt). The term ‘systems engineering’ suited well, and groups of people were noising it around by then. It sounded nice and, after all, a quarter-inch bolt is a fastening system of high complexity. It consists of a bolt with threads (helical inclined plane), a nut of the proper size, hand and thread configuration (bolt interface problem), external shape (wrench interface problem), one or more washers (structures interface problem), and sometimes even a cotter pin (reliability).

Moreover, one could dream of performing systems engineering at increased hierarchical levels by considering at one and the same time not only the quarter-inch bolt, but also the half-inch bolt. Advanced systems engineering. So much for the history and meaning of systems engineering. You can demonstrate the validity of my story to yourself in several ways. Your letter, for instance, can be clarified by eliminating the word ‘systems.’ I believe it appears 10 times. Check the universities for courses in systems engineering and find out what they are really teaching. Note also that the term ‘systems engineering’ does not yet appear in an accredited dictionary. This is because Webster cannot figure it out either. Good luck!

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