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Dave Palmer
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Platinum
Re: Systems engineering the key
Dave Palmer   3/29/2012 5:55:11 PM
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@williamlweaver: Great comments on the importance of systems thinking.  In failure analysis, there's a tendency to focus on the part which failed, rather than the mechanical system which it belongs to.  People tend to ask, "What's wrong with this part?" rather than, "How was this part loaded?"

As a metallurgist, people often send me a broken part in a box and expect me to tell them why it failed.  Sometimes, I might be able to find something (such low hardness or microstructural defects) which would tend to make the part more likely to break.  But without understanding the application, I can't tell them why it broke.  Finding a defect in a part is not the same as finding the root cause of a failure.

A consequence of this, as I've discussed elsewhere, is that the knee-jerk response to a part failure is to make the part stronger.  This often results in a failure occurring somewhere else in the system, so the next part to break is also made stronger, and so on.  Ultimately, it results in designs which are unnecessarily heavy and expensive, while underlying root causes are never addressed.

A Chinese friend of mine, who is a philosophy professor, says that Western cultures tend to be reductionist, while Asian cultures tend to be holistic.  I think that reductionism (breaking things down into their simplest parts) is actually an incredibly powerful tool, but it needs to be complemented with a holistic (or systems) view.

xti
User Rank
Iron
GM Engineering vs Management
xti   3/29/2012 2:09:43 PM
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If you want to get an idea of how convoluted GM is regarding engineering vs. management, read the book "All Corvettes are Red" by James Schefter. It's about how the C5 (1997) Corvette came into being - and how it almost never existed.

A lot of the C5 had to be built in secret - even from GM.

After reading this book, you will appreciate just how astounding it is that GM is able to build anything at all, let alone Corvettes.

Although this book was written many years ago, looking at the present crop of crap from GM and others, I doubt much has changed. I'm sure many of the other manufacturers have similar issues.

The book is a graphic picture of what happens when bean counters run a company instead of people with a passion for what they produce.

In the case of the Corvette, passion won, but only barely.


williamlweaver
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Platinum
Re: Systems engineering the key
williamlweaver   3/29/2012 1:09:29 PM
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Thanks @Chuck! I've commented directly on the article you provided. Way awesome stuff. I'm dismayed that seven years later, we are not using the functional Build more publically.

Charles Murray
User Rank
Blogger
Re: Systems engineering the key
Charles Murray   3/29/2012 1:05:38 PM
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Bill, you might want to look at this article from 2005.

http://www.designnews.com/document.asp?doc_id=220035

 

ervin0072002
User Rank
Gold
Lasts to Long?
ervin0072002   3/29/2012 10:22:45 AM
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Another issue that follows due to cost reduction is life expectancy. This is a two sided benefit to the automakers in the USA. One side of it is cheaper materials meaning a lower cost to make an automobile. Price reduction to cost savings is not in par either. Most of the cost savings go to the automaker. The other flip side of the coin is the life of the product is reduced. And USA automakers see this as opportunity gained because it means more replacement parts for the cars already in sold.

 

Complexity of design is also an intended feature. I have had several US made cars and a Toyota. To do simple maintenance sometimes on the US cars is so frustrating you are always tempted to go to the dealer. Try changing the thermostat on an impala 2001. Also to remove the tensioner for the belt on a corolla 2005 you have to lift the engine block by half an inch???? Of course I just cut the bolt instead and torqued another bolt that was half an inch shorter. I can do that because I have vibration experience. It's actually my specialty and I know that bolt will not loosen due to vibration. Average Joe usually does not carry this knowledge around and will be forced to send it to a dealer.

williamlweaver
User Rank
Platinum
Re: Define "Quality"
williamlweaver   3/29/2012 9:15:26 AM
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@GlennA - Management was swayed by the late 1970's gas cruch and decided the Fiero would be a "fuel-efficient sporty commuter"... sort of the Pontiac Chevette, rather than the Pontiac Corvette... http://en.wikipedia.org/wiki/Pontiac_Fiero

GlennA
User Rank
Gold
Define "Quality"
GlennA   3/29/2012 9:02:16 AM
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"Quality" is a misleading word.  In manufacturing, Quality is conformance to specifications.  So if your design specification is junk, you can make "quality" junk.  And Defect does not equal Defective.  "Defective" may mean 1 or 2 Major Defects, or possibly 4 or more Minor Defects.

Quality is also "in the mind of the beholder".  I remember the story of a driver who was willing to wait 2 weeks for parts for his Mercedes - "a fine piece of automotive engineering", but complained that getting parts for his Dodge would take 2 days = "piece of junk".

I agree that engineers may be hampered by the limits set by upper management.  I wonder who decided that the Pontiac Fiero, which I thought was supposed to be the Pontiac Corvette, would have a 4 cylinder engine.  We called it "All show, no go".

naperlou
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Blogger
Quality Differences
naperlou   3/29/2012 9:00:53 AM
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Chuck, given what you said, it is interesting to note that the differences in overall quality that I have seen are miniscule.  The Consume Reports methodology is tailored to their own measurement systems.  I have in the past picked products (not including cars) that were not high in their estimation, but that worked great for me and others who had them. 

I prefer those measures that track actual reported defects over time.  In those, as I mentioned, the probablity of experiencing a defect with any of the automobiles offered today is much lower than it was ten or twenty years ago.  In addition, the difference in manufacturers  rates of defects were close to zero.

I like a well laid out system as much as anyone else.  On the other hand, for consumer level products, it is the results that count.  Just listen to Car Talk on NPR.  Most of the people who call in have foreign made cars that are older.  They have problems.  A car won't last forever without a lot of work.  I know, I started out with small English sports cars made in the 1960's.  Fun, stylish and incredibly unreliable.  We often said that those parts we had the most trouble with were designed by the junior engineers.  There were other parts that would last forever. 

williamlweaver
User Rank
Platinum
Re: Systems engineering the key
williamlweaver   3/29/2012 7:50:08 AM
@Chuck -- in a nutshell "Those manufacturers, the Center says, tend to think in terms of systems, rather than individual parts." Wow, does this hit it right on the head. I've been teaching Systems Thinking to undergraduate future technical managers since 2000. The idea of "parts make systems" rather than "systems are comprised of parts" is something that takes quite a while to transform in our students. Not knocking 12-years of elementary and secondary school, but they too often take a bottom-up approach when it comes to teaching concepts -- picking up seemingly random concepts that are only integrated in the much higher grades, if at all. In my own experience, I didn't get the value of algebra, geometry, trig, and calculus until I took Differential Equations and applied it in my Physics and Engineering Mechanics courses. 

One of the memes I use in my Systems courses is "Start from Scratch rather than Patch" -- bolting on components makes a product "multi-functional" but it does not make it "inter-functional". When each of the component parts is integrated into the design with an awareness of the other parts, the concept of "elegance" is allowed to emerge...


Beth Stackpole
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Blogger
Systems engineering the key
Beth Stackpole   3/29/2012 6:42:28 AM
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This post offers a pretty insightful look into the psyche of how auto makers come at creating a culture around product development. The thing that stood out to me is the whole Japanese focus on looking at engineering from a systems standpoint. Not a new concept, certainly, but definitely one we are hearing spades about as products, be it cars or aircraft, get more complex.

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