GM Ignition Switch

[drwebb]

No Monday morning quarterbacking of this fiasco? Was it a lone engineer, acting independently, or part of a much larger conspiracy to bring down Government Motors hatched by Jimmy Hoffa, Fidel Castro and the mob? Who's up to formulate a 'magic detent' theory? This board was all over the Toyota Unintended Acceleration brouhaha but I'm not seeing much on the domestic's recent troubles. Everyone on summer break? Under secrecy agreements (-or subpoena!)? What gives??

 

[IRstuff]

They fired 11 and suspended another handful...

TTFN
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[GregLocock]

I suspect a series of junior managers heard what they wanted to hear from the experienced design team and believed that each minor change would be the end of the problem. Think about the effect on your career - insist on complete redesign and revalidation, say a million bucks, or accept the word of your design team.

Cheers

Greg Locock


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[IRstuff]

I would bet that like the two Shuttle disasters, management heard what they wanted to hear, but demanded absolute proof for things they didn't want to hear from the engineers. Since it's almost impossible to positively prove things of this nature, the engineers are blamed for not supplying sufficient data. Rarely have I ever had any discussion with engineers where they were willing to suspend disbelief, but management is usually eager to do so.

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[GregLocock]

I wonder who got sacked, other than the design engineer. I think every one of his supervisors over the years should have got a very hard time, and the quality manager who was involved in each investigation. I'm guessing that from now on if engineers want a safety related problem fixed properly they'll just have to say "GM ignition switch" and watch the ball start rolling.

Cheers

Greg Locock


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[GregLocock]

"the automaker announced 15 individuals with ties to the ignition switch recall were fired. Of those no longer employed, seven have been identified thus far:

Ray DeGiorgio: Engineer
Mike Robinson: Vice president of sustainability and global regulatory affairs
Gay Kent: General director of vehicle safety
Carmen Benavides: Director of field product investigations
William Kemp: Senior lawyer, safety
Gary Altman: Program engineering manager
Lawrence Buonomo: Senior lawyer, product liability"

ie a bunch of senior people get golden parachutes for the good of the company. I expect they'll be back on contract soon enough.

Cheers

Greg Locock


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[DanEE]

...."But GM has since told the Associated Press that regulators were mistaken: the cars only had enough reserve power to sense a crash and deploy the air bags for 150 milliseconds after the switch malfunctioned and cut off the car’s power."

From The Detroit News:

http://www.detroitnews.com/article/20140514/AUTO01/305140024#ixzz33uojCAe4

The switch is only part one of the problem.. As documented in the above article the GM airbag system design in the affected cars will only fire the airbags for 150ms period of time after power has been lost to the system.. In the early phases, particularly in a multi-strike crash, power can be lost due to the battery/wiring being ripped out in the initial stages of the collision, leaving no power to fire the bags when they should have been commanded.

I know from Toyota collision repair manual documentation, Toyotas employ an energy storage design in the air bag control system that is capable of firing the airbags and seat belt tensioners for up to 90 seconds after power has been removed.. Before welding or doing any other maintenance activity on the vehicle that could possibly trigger the air bag system, the battery cable must be removed and allow 90 seconds to elapse before proceeding. And they warn, just turning the ignition switch off isn't sufficient..

Not idea what other manufacturers systems do...

 

[Comcokid]

According to the news, it was the original design engineer who called it the "switch from hell". DeGiorgio is another engineer who later made some minor somewhat undocumented tweeks to the switch - apparently a poor band-aid. I would like to see more of the full story at the design end.

In my experience in other industries, I've seen many a bad design where management would allow only tweeks, and what was needed was a clean sheet restart of the design. In the end, a restart would have proven the least expensive and fastest path to a fix.

 

[TheBlacksmith]

Most of these rules were broken, as they are at my company, and I suspect most companies. No conspiracy, just an overwhelming desire to contain costs, maintain schedule, and not upset anyone.

Lambert’s Laws of Design and Development

Law #1 Build in enough design margin to counteract the effects of minor manufacturing deviations and customer misuse.
It is difficult to make a product foolproof since fools are so ingenious, but any product incapable of being produced and operated by "real" people should not be turned loose in the real world. We have a right to expect that our designs will be tooled and processed in a way that will meet the basic drawing requirements; also, that our customers will observe our published ratings and read our application manual. We have that right, but we should know better. Therefore, the slightest deviation from the straight and narrow should not result in total disaster. A little loss of performance? Perhaps, but not for every design transgression. Thus, Law #1 implies that we will plan to probe the design boundaries during the development program to establish our true design margins, and that we will extend the margins when feasible.

Law #2 When there is a problem, any action is better than none. (That is, don't just stand there - do something!)
This law agrees with Murphy, who says that if you leave it alone it will only get worse. It also follows a dictum from Indiana basketball coach Bobby Knight: "Both be a good leader or a good follower, and, if you can't be either, for heaven's sake get out of the way." If it works in basketball, it should work for engineering. Besides, the laws of probability tell us that three logical or seemingly appropriate decisions will yield an 87.5% expectation of success - even if each decision has only a 50% probability of being the best that could be made. All of which should remind us that our real enemy is indecision. The odds on success per decision per decision can be increased materially if each action has a sound engineering reason. The converse to this is that we should steadfastly refuse to accept a solution founded solely on unexplained phenomena. When witchcraft and black magic are used, the whole solution can disappear the first time someone sticks a pin in our doll. In any case, don't just keep running the same thing and hoping for the best.

Law #3 There is a definite hierarchy of priorities in solving development problems.
Priority 1 - What will produce the maximum gain for minimum cost in the shortest time? Priority 2 - What is the most positive absolute solution with no question of adequacy? While directing initial attention to Priority 1, it is well to start work toward Priority 2 just in case. If we miss them on the roundabouts, we'll catch them on the swings. While time and cost cannot be ignored in the second case, they are subordinate to absolute certainty. Above all, the product must work. No shortcoming will ever be forgiven. Until the problem is solved, always have an alternative in mind and be working on it. This follows the theory that when 2 + 2 refuse to make 4, try 3.

Law #4 If you find that a change is unavoidable, make sure the change you do make is completely adequate - don't skimp. If there is any choice, overpower the problem rather than trying to finesse it. In poker, one Smith and Wesson beats four aces. In engineering, one positive fix beats four probables. As a corollary of this law, no change should be considered truly significant unless it makes an improvement (in stress, bearing pressure, deflection, etc.) of at least 25% - and 50% is better, considering the scatter band of material properties. This faithfully follows the theory that if a little bit goes a long way, try a lot. Confronted with a failed part, any metallurgist worth his salt can always find something wrong. It is tempting to accept this finding as the full answer, but minor changes in heat-treating or metallurgical quality rarely affect physical properties by as much as 25%, so we often need to look further. Every engineer knows that even a very good design can suffer a random failure. He sometimes forgets that even a bad design can sometimes enjoy a random success, but the fundamental weakness remains.

Law #5 Be intellectually honest. If you have a theory, have the courage to put to an unbiased test.
(Note: This runs contrary to one of Murphy's Laws which says: "Never replicate a successful experiment.") Running a test first and rationalizing the results later does not constitute a proof; it only illustrates a potential theory. The theory is not proven until you can turn the phenomenon on and off at will. Going back to Law #2, do not settle for one random success. It may never happen again.

Law #6 In any endeavor, take a positive, aggressive approach. Force Action.
Once the drawings are changed, once the parts are ordered, once the test plan is written, once the failed parts are sent to metallurgy, it is tempting to sit back and relax knowing that someone else momentarily has the ball. Don't do it! You are still accountable. Check schedules. Find shortcuts. Clear roadblocks. Buy coffee. Be a squeaky wheel. And don't make excuses. Your friends don't need them and your enemies won't believe you. Apply all that energy to finding a way. There is always a way. As Confucius (no doubt) said, "If you can't raise the bridge, lower the river."

Law #7 Never mislead a customer (or management).
If there has been an unexpected problem or the product has developed leprosy, you might as well admit it. The customer (or management) will discover it eventually anyhow. It will be nicer if they hear it from you. The only antidote is to have a rational explanation available and a viable plan of attack. This may require some quick thinking, but that is what you are paid for.

Law #8 If a job is worth starting, it is worth finishing. Or...Never start a job unless you intend to finish it.
This follows on Lambeck's negative postulate, which says: "Just because something has a beginning, it doesn't mean it has an end." Many engineers, being both born perfectionists and avid experimenters, will tinker with a product far beyond the Law of Diminishing Returns. Some, in fact, will tinker with it until it no longer works and they have forgotten the road back. A restatement of Law #8 might read: "Good enough is perfect." An adequate product delivered to the field beats two nearly perfect products hung-up in the lab.

Law #9 Stop writing memos. If you want to communicate, talk to people.
A memo is good for only two purposes: Disseminating useful information or recording an agreement. When it asks a question (Have you stopped beating your wife?) or voices a complaint (Why haven't you stopped beating your wife?), all it does is set off a negative reaction...followed by a return memo. There is nothing as futile and unproductive as a memorandum war.

Law #10 Do not blindly follow orders from above (including mine). If you have convictions, hang in there.
Do your own thinking. Be your own person. Rely on technical judgement. And speak up!