Curious, what is your definition of engineering judgement 1

[xkcstructural]

I had posted about ethics in residential and I found that "engineering judgement" gets used when the area is grey which is what judgement is so makes sense, But I'm curious what other engineers residential/commercial think what engineering judgement is.

 

[BridgeSmith]

To me, the short answer is any design decision made beyond the scope, or deviating from, the accepted codes or specifications.

When you get a knot in the pit of your stomach when you get ready to put your stamp on something, you know you've made an engineering judgement call. For me, that's pretty much every time.

 

[XR250]

One type, for me, it is knowing something will work when I take into account all the mechanisms involved, but it would be hard to prove on paper.
Also, knowing something will not work on paper but the chances of it failing are extremely small.
For instance, a slightly overspanned crawlspace girder in a three story house. You know that the chances of full design loading are zero and it's likely twice as strong as we give it credit for.

 

[MotorCity]

A design related, conservative decision or rationalization made by the engineer based on his/her experience, education, intuition, and/or technical merit rather than codified or prescriptive requirements.

 

[JStephen]

On any given item, there is literally no end of analysis that COULD be done on it, and one aspect of engineering judgment is knowing what actually needs to be analyzed or calculated.

 

[jerseyshore]

I agree with XR.

For me engineering judgement is knowing when something is okay even when it's not exactly "by the book" but also knowing when something absolutely positively has to be designed/ constructed to a high standard.

 

[Greenalleycat]

Engineering judgement is a funny one that we discuss in our office quite a bit
Despite it being a very common fallback, it doesn't really appear in our Building Act or Building Code legislation
These are pretty black-and-white that it has to perform, and you're up for a lawsuit if it doesn't - regardless of your judgement or not

That said, obviously 'engineering judgement' is used every day and every project to figure out wtf is going on
Common items to me are figuring out what load cases are likely critical, when you should or shouldn't check welds (95% of welds are way overspecced due to FWAR being used, for instance), and so on
Other times, you get problems that are out of the ordinary and need to be broken down into solvable problems that code may or may not capture

 

[dauwerda]

Despite it being a very common fallback, it doesn't really appear in our Building Act or Building Code legislation
These are pretty black-and-white that it has to perform, and you're up for a lawsuit if it doesn't - regardless of your judgement or not

Keep in mind, when it comes to lawsuits and the blame game, engineers (and their designs) aren't held to "the code", they are held to the "standard of care". The standard of care is how engineering judgment gets accounted for. Ron, here on Eng-tips, has a great document (course) that addresses this, and other things important to contracts at

http://www.pdhonline.com.

You can get the document here:

https://www.pdhonline.com/courses/p112/EveryWordCounts-1203.pdf

 

[Greenalleycat]

Not everyone in the world lives in the US, mate. Our laws and codes are the same but different. The governing criteria for us is whether it meets the performance expectations of the Building Code. If not, ring your insurer. My understanding is that 'engineering judgement' or 'what would a reasonable engineer do' will be valid in negligence or criminal proceedings, or in investigation from the engineering authorities (in the highly unlikely situation that these occur) but they will not stop you being sued and held to account for failed performance.

 

[dauwerda]

Not everyone in the world lives in the US, mate.

Fair enough! The OP does, so while I did quote you, I was hoping it would be useful information to the OP as well.

"but they will not stop you being sued and held to account for failed performance."

If something goes wrong on a project, it's my understanding that you (the EOR) will pretty much be guaranteed to be named in a lawsuit regardless of if everything was designed to code and you had all your i's dotted and t's crossed. That's the entire point (well, it's A point, not the entire point) of the lawsuit - to determine if you missed anything in the design that you shouldn't have. Luckily for us, when it get's to that point, you aren't expected to be "perfect" you are expected to meet the standard of care.

 

[Greenalleycat]

We are governed by two aspects, Code of Ethics (duty of care?) and performance expectations. From the liability aspect, it does not matter if you meet the Code of Ethics if your design ultimately fails to meet the code-specified performance expectations. You are the engineer and it is your job to make sure your client's job performances satisfactorily, the buck stops with you. The only way out is to pin the blame on someone else e.g. the contractor for building it wrong. But if your design is deficient, it's deficient, even if you've followed the relevant standard

 

[YoungGunner]

But even the code has plenty of grey area that can't be interpreted the same. We were pulled in as a expert witness to a building where clearly the contractor didn't build per the specs, but, because oustide witness engineers got involved, they began getting real nitpicky with the original engineer's topographic factor. Both engineers who looked at it argued two different topographic factors, 1.5 and 1.7. "Engineering judgement" at its finest even when the code is involved.

I agree that if we are in a legal battle and other engineers are brought in, they will hold to the code in their argument which will always trump the "gut feel" of the original engineer. However, the trick with "engineering judgement" is to use it in areas that, as was touched on by another comment, you have near absolute certainty that the true design loads will never be reached.

The funny thing about codes is they are always evolving. It's funny to see how ACI 318-19 DRASTICALLY hurt shear for thicker concrete members compared to previous years. Will the buildings built under the old code suddenly fail? Likely not - because there were plenty of safety factors at play. So despite how future concrete structures are built and the "code level" they were at, there is still a generation of buildings built under an old code that will "theoretically fail" but won't. I use this example not to say we shouldn't design to most recent codes, but to imply that the most recent codes still aren't perfect, which means there is room for GOOD engineering judgement in areas that it doesn't explicitly cover.