Richard Feynman, the Challenger, and Engineering

An anonymous reader writes "When Richard Feynman investigated the Challenger disaster as a member of the Rogers Commission, he issued a scathing report containing brilliant, insightful commentary on the nature of engineering. This short essay relates Feynman's commentary to modern software development."

Comments

External Pressures Ruin Engineering

[eldavojohn]

I'm a software developer. I would like to think of myself as an engineer but to me that's a higher title that belongs to people who actually engineer original ideas.

The problem with the shuttle disaster (both of them, really) is external pressures that are not in anyway at all scientific. The pressure from your manager at Morton Thiokol to perform better, faster and cheaper. The pressure from the government to beat those damned ruskies into space at all costs.

So this is really a case of engineering ethics, when do you push back? As a software developer, I never push back. Me: "There's a bug that happens once every 1,000 uses of this web survey but it would take me a week to pin it down and fix it." My Boss: "Screw it--the user will blame that on the intarweb, just keep moving forward." But could I consciously say the same thing about a shuttle with people's lives at stake? No, I could not.

So when an engineer at Morton Thiokol said that they hadn't tested the O-Ring at that weather temperature that fateful day and that information was either not relayed or lost all the way up to the people at NASA who were about to launch--it wasn't a failure of engineering, it was a failure of ethics. External forces had mutated engineering into a liability, not an asset.

And there's a whole slough of them I studied in college:

* Space Shuttle Columbia disaster (2003)
* Space Shuttle Challenger disaster (1986)
* Chernobyl disaster (1986)
* Bhopal disaster (1984)
* Kansas City Hyatt Regency walkway collapse (1981)
* Love Canal (1980), Lois Gibbs
* Three Mile Island accident (1979)
* Citigroup Center (1978), William LeMessurier
* Ford Pinto safety problems (1970s)
* Minamata disease (1908-1973)
* Chevrolet Corvair safety problems (1960s), Ralph Nader, and Unsafe at Any Speed
* Boston molasses disaster (1919)
* Quebec Bridge collapse (1907), Theodore Cooper
* Johnstown Flood (1889), South Fork Fishing and Hunting Club
* Tay Bridge Disaster (1879), Thomas Bouch, William Henry Barlow, and William Yolland
* Ashtabula River Railroad Disaster (1876), Amasa Stone So I agree with Feynman's comments in relationship to engineering and the further comments to software development. But I don't find them to be a fault in the nature of engineering, just a fault in our ethics. What does capitalism and competitiveness drive us to do? Cut corners, often.

Re:External Pressures Ruin Engineering

[DBCubix]

The Kansas City Hyatt Regency walkway collapse was an engineering problem. The contractor asked to take a shortcut (instead of threading a nut up a three story threaded rod, they asked to cut the rod and offset it several inches) and the engineers rubber-stamped it without checking what the ramifications would be. The engineering part was not originally flawed, but it was when they approved the change order.

Re:External Pressures Ruin Engineering

[Vicious Penguin]

> What does capitalism and competitiveness drive us to do? Cut corners, often.

Maybe, but remember what your own example shows -> What is the cost/benefit of fixing/preventing an error? Is a week of debug time worth missing your target ship date? Maybe, maybe not - depends on the error.

A blanket indictment of capitalism is quite unfair. You would still have the same cost/benefit analysis regardless of economic system you toiled under.

Is is not possible to engineer against all eventualities; trying to do so will usually keep you from ever getting off the ground.

Re:External Pressures Ruin Engineering

[esocid]

Apparently you've never taken engineering ethics. The first class I had to take as a general engineering major. Needless to say, I changed majors but still got a hell of a lot out of that ethics class. The parent was right. These were all cases of cutting corners, either in terms of cost or time. Managers wanted it done quickly and cheaply, whether that meant mixing concrete improperly, or buying sub-par materials, or just ignoring what the engineers are telling them. It always came down to about 95% managerial and the rest engineering error.

Re:External Pressures Ruin Engineering

[Sanat]

I stayed at this Hyatt over several different weekends while there was dancing and music on the ground floor. What would happen is that several individuals would get the walkways to start swaying and then reinforce the sway by shifting their bodies at the right instant causing additional sway from the positive feedback. it was not unusual to experience 3 to 4 inches of sway.

Although this swaying is not normally mentioned in the articles about the construction of the Hyatt, it went a long way towards weakening and stressing the connectors supporting the floors.

Two of my friends were dancing on the floor when the walkways gave way and both were killed.

Faster, Better, Cheaper

[Protonk]

To be fair, the Challenger disaster actually preceeded NASA's slogan and procurement policy of "faster, better, cheaper" by a bit. More to the point, Feynman's article should be a cautionary tale to ANYONE in a engineering field. It isn't a matter of one field being subject to unscientific pressures and another field being immune. No technology or industry is immune from the pressures and problems that caused the challenger disaster. Anyone who claims to be well adapted to safety concerns enough to not spend lots of time and effort on fixing them is foolish. The nuclear industry still has to practice strong QC on parts, procedures and maintenance and CONTINUE that practice. Same with commercial aviation, acute medical care, etc. Constant vigilance is rewarded only with another uneventful day. That is the fundamental problem. Vigilance is expensive and time consuming. these are not pressures from the profit motive. They apply to government as well as civilian ventures.

Tag on to a famous essay...

[sphealey]

(I will refrain from a four-step Profit post). Standard technique: latch on to an essay by a brilliant and insightful person. Extend the insights of that person slightly into a different field with usual compare-and-contrast, brand-extension writing techniques. Claim that resulting essay (and self) are as insightful as the original essayist.

It doesn't work 99.994% of the time, generally because very few people are as insightful as the original brilliant person.

sPh

Hm.

[gardyloo]

The blog post makes a nice contribution by linking to Feynman's original thoughts (for example, here: http://www.ranum.com/security/computer_security/editorials/dumb/feynman.html ), ones I haven't read for a long time (and was happy to be reminded of). However, the author makes the mistake of thinking that the original thoughts need to be interpreted and summarized for the reader. Feynman's words by themselves are simple to understand, are concise, and contain just the tone for which geeks go gaga. Anyone interested in the subject will be able to make his or her own judgements about the engineering and politics involved in the Shuttle development, engineering in general, and the extensions to software development.

As a software quality professional...

[gosand]

I've been in software quality and testing for 14 years. I've worked at very large corporations as well as startups. There is a WIDE gap in software development process in our industry. Many people like to call themselves software engineers when they are developers. There is a huge difference. Engineering is a discipline that follows well-defined rules, and it usually takes time. But I think the very important thing to point out is that some software requires engineering - other software does not. If I go into a startup company that is trying to develop a blog/wiki site and try to implement a NASA-like software development methodology, they will fail. Likewise, software to control a heart monitor should be engineered and closely controlled. Sometimes quality and perfection is the goal, other times it might be time-to-market that is critical. You have to fit the process to your business. A bridge is a bridge, and they should all be engineered pretty much in the same way. You can't say the same thing about software.

I think that this is a very key point to software development. I have seen companies who spent entirely too much time and money trying to eliminate all defects from their software when it wasn't the critical part of their business. Yes, we should always strive to eliminate defects, but you can't get them all. You have to know when to pick your battles, and when to accept the risks. If we're talking about life-or-death software, or security, or other very critical things - you need to focus on those.

There's a grid I have seen used that is a great tool when doing projects.
Schedule, Cost, Quality, Scope.
1 can be optimized, 1 is a constraint, and the other 2 you have to accept. Period. It is a more useful version of the "fast, good, cheap - pick two"