HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Nancy Golden
User Rank
Platinum
Value of Engineer's Experience
Nancy Golden   5/11/2014 3:21:05 PM
NO RATINGS
"It's often the engineer's experience and judgment that plays a key role in setting the numerical value for the factor of safety."

Reminds me of the chief engineer on the Enterprise:

[the U.S.S. Enterprise is being sucked into a black hole, seconds away from doom]
Scotty: I'm giving her all she's got, Captain!
[the bridge ceiling begins to crack as the ship's drawn closer]
James T. Kirk: All she's got isn't good enough! What else ya got?
Scotty: Um... Okay, if we eject the core and detonate, the blast could be enough to push us away! I cannae promise anything, though!
[the viewing window starts to rupture]
James T. Kirk:  DO IT, DO IT, DO IT!

Probably not a scenario he would have used a computer model for...

While a work of fiction, it still speaks to the importance of factoring in an experienced engineer's judgment that may not necessarily agree with a computer model...and that "sufficient" can also depend on the situation.

jhankwitz
User Rank
Platinum
Re: Consumer
jhankwitz   5/8/2014 12:49:07 PM
NO RATINGS
From where did you get these "laws"? According to these statements, "sufficient" is not attainable except for one producer.

Debera Harward
User Rank
Silver
Re: Sufficient is Subjective
Debera Harward   5/8/2014 12:37:48 PM
NO RATINGS
@totally agreed sufficiency of anything varries from person to person and no two person are alike so there perceptions , desires and wants cant be same however there needs can be same.

jhankwitz
User Rank
Platinum
Re: Sufficient is Subjective
jhankwitz   5/8/2014 12:32:04 PM
NO RATINGS
I agree.  What I'm saying is that "sufficient" (as much as needed) is very subjective and based on individual perspective and opinion.  My wife and I have very different views on how many diamonds are 'sufficient' for her wardrobe. One may be necessary or required to display her merital status, but we don't agree on the sufficient number.

Debera Harward
User Rank
Silver
Re: Sufficient is Subjective
Debera Harward   5/8/2014 12:08:58 PM
NO RATINGS
Necessary is basically the requirement, the need, the necessaty and sufficient is basically having provided as much as needed .

Battar
User Rank
Platinum
Consumer
Battar   5/8/2014 9:09:33 AM
NO RATINGS
In consumer products and appliances, the laws state - 

"necessary" = MTBF must be 3 months greater than the warranty period

"sufficient" = MTBF must be 3 months greater than that of your competitors' product

"Safety" = whatever is the minimum requirement to pass TUV/GS/ETL/UL certification.

Cabe Atwell
User Rank
Blogger
Re: NECESSARY AND SUFFICIENT
Cabe Atwell   5/7/2014 10:25:15 PM
NO RATINGS
That is a perfect example bobjengr. I don't think there's a finer example of what 'necessary and efficient' is all about. 

bobjengr
User Rank
Platinum
NECESSARY AND SUFFICIENT
bobjengr   5/7/2014 6:06:26 PM
NO RATINGS
This is an excellent post--excellent.  I had a professor who always stated, " the only thing less desirous than an undersign is an over design.  He was all about applying the proper safety factors to design problems and stressed that to all of his students.  You were automatically "dinged" if you did not state and apply safety factors and how those affected the assembly of components.  

I think we have just seen a remarkable violation of "necessary and sufficient" with programming and launch of the "Affordable Healthcare Act".  A disaster due to improper planning and bogus architecture.  Our country could definitely benefit from reading your post. 

naperlou
User Rank
Blogger
Re: Sufficient is Subjective
naperlou   5/7/2014 3:47:22 PM
NO RATINGS
That is a good point.  The sufficient condition is usually the bounding condition.  The necessary condition is that which is called out specifically in the specification.  Of course, this assumes the requirements are correct.

jhankwitz
User Rank
Platinum
Sufficient is Subjective
jhankwitz   5/7/2014 9:10:18 AM
NO RATINGS
Great article.  "Necessary" is often fairly easy to calculate knowing what is needed, but that "Sufficient" number can vary all over the place depending on perspective.  I think personal experience is a variable that can have great impact on what is sufficient, so can lead to a lot of debate among peers.  How safe is safe? How much is too much?



Partner Zone
Latest Analysis
Check out these strange technology acquisitions. Many of these mergers became burdens the companies couldn't bear.
The Strati EV car printed at IMTS is made of SABIC's LNP STAT KON AE003. SABIC tells Design News why this carbon fiber-reinforced compound was chosen by Local Motors and Oak Ridge National Laboratories.
The 2014 Ig Nobel Prize in Physics was awarded to Dr. Kiyoshi Mabuchi and his team members for their work measuring the slipperiness of banana peels. Turns out they're slipperier with the yellow side up.
Many scientists have been working battery-free ways to power wearable electronics that can replace bulky battery packs, particularly through the use of energy-harvesting materials. Now a team of researchers in China have upped the game by developing a lightweight and flexible solar cell that can be woven into two-way energy-harvesting fabric.
Researchers in Canada have developed a chin strap that harvests energy from chewing and can potentially power a digital earplug that can provide both protection and communication capabilities.
More:Blogs|News
Design News Webinar Series
9/25/2014 11:00 a.m. California / 2:00 p.m. New York
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
10/7/2014 8:00 a.m. California / 11:00 a.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Oct 20 - 24, How to Design & Build an Embedded Web Server: An Embedded TCP/IP Tutorial
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: October 2
Sponsored by Altera
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service