What is your firm's policy for checking structural engineering calculations? 3

[bolt45]

Does your firm have a standard policy for checking structural engineering calculations?

Does everything have to be checked by somebody? Or do only certain things get checked? Does nothing get checked? I'm just curious what the norm is in the industry for quality assurance of design calculations.

 

[fancypants]

This is something that sticks somewhere in my throat. Where I work there are no policies and pretty much nothing gets checked. This is not by design but by the nature of how business is conducted. Everything seems to be hurry up, hurry up. Deadlines are much too soon and the cart is ahead of the horse. No geotech report, no problem, let us just guess on the permit set and fix it later etc... etc.... Now my mood is deteriorating LOL.

I wish things were checked and double checked. I know for a fact that errors are happening and I am just waiting for the one OH MY error to happen.

 

[PicoStruc]

Where I work :

- The boss check if the result of the design make sense on the drawing ! (judging by experience !)

- Calculations are never checked except if the employee says scary things that would lead the boss to doubt the competence of the engineer...

 

[ash060]

Check what?

Except for one office that I worked in, I have never had any type of QA/QC. Usually the fees and schedules do not allow for any kind of checking much less designing. This always worries me as I catch a bunch of mistakes while doing the calculations, so that probably means that I am missing just as many or more than I catch.

It is getting harder and harder to provide a good product for the fees that we are able to charge. Unfortunately, we do not have the marketing leverage to demand higher fees or the volume to work on only the jobs we want.

But I try to remain optimistic about the direction of the profession and that our clients we start to see us more as a beneficial professional service and less like a "necessary evil" engineering commodity.

 

[SteelPE]

How does one check calculations if you are the only one creating the calculations?

I do some consulting work with other engineering companies. A few weeks ago I was blasted for taking to much time to review calculations and how other consultants are not as difficult as I am. I proceeded to find 2 simple mistakes in the attachment they sent over that made a huge world of difference in the design. Needless to say, they were quite embarrassed. hahahaha

 

[msquared48]

I'm so busy catching my own mistakes, I don't have time to check on other people!

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[MiketheEngineer]

We do "casual" checks. Lets say you have an 8' W8x10 beam carrying 1000 lbs. and braced. That is obviously OK. But say it is carrying 10,000 lbs and can't be braced. I am going to look at that very hard!!

So it sort of depends on what is going on!!

 

[JedClampett]

Unless the client insists on seeing reviewed calculations (and pays us for them), we don't formally review them. However, all drawings are reviewed. Most of us have a pretty good idea of what works, so while we're reviewing the drawings, we run informal calculations to verify reinforcing and/or member sizes. If I see a 20 foot tall 8 inch CMU wall, with #5's verticals at 3'-4", I'm likely to run a number on that. If I see a 12 foor wall with #5's at 2'-0", I'm probably going to allow it. And if I see one mistake, I'm likely to review that type of component pretty tightly for the rrest of the project.
I've always considered reviewing calculations somewhat counter productive. It's so time consuming, that the end product (drawings) are slighted. Plus, it gets you caught up in the minutiae of the numbers, when you might miss a whopper of a mistake in the whole approach.

 

[TLHS]

Yeah, my company doesn't really have any requirements at the moment, but if something's going out with my stamp or otherwise under my supervision, I'll review the drawings with an eye for strange things. I'll have one set of check prints where I'll scrawl all over it in red with math so that I have a record of whatever I've looked at. It'll just be sanity checks for most things. Check the longest span beam, unusual connections, a quick check of the lateral system and slenderness of braces. Basically, stuff that would make the structure unsafe, plus whatever else is unusual. I'll size things up in this kind of check sometimes, but won't normally size things down without a very large discrepancy and a discussion with the original engineer. I'll also have a discussion with whoever did the original work to ask conceptual questions and see if they checked everything I'd check. If I get any confused answers back, I'll normally have a harder look at things.

I prefer doing that over checking calculations, because you can't fall into the trap of being led by the other engineer's math. It can be easy to duplicate someone's mistakes when you're following their math. If they've come up with a neat concept, or something that you wouldn't normally catch they can explain it when you go and ask why some beam looks like it's sized incorrectly.

 

[paddingtongreen]

Strange. I haven't ever worked in an office where anything went out without checking. The only exception was when I was the only structural person in a group doing onsite design to modify a refinery. I spent a considerable time in the nuclear business, there we had to check off that we had checked the method, the inputs and the detailed calculation. Then it was peer reviewed.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[SLTA]

I have my own company so I check my own work. I put it down for a day or two and come back to it totally fresh. When I worked for big companies, pretty much no one checked anything. *sigh*

 

[GregLocock]

Wow. The truth about the PE stamp comes out.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[bridgebuster]

20-30 years ago, when I was at a small firm, we checked everything. For the past few years I'm with an ISO certified firm - procedures, forms, QA police up the wazoo - nothing much gets checked in detail, As long as the form is filled out...

 

[hokie66]

In my company, the amount of checking of calculations depends on the senior engineer who is doing the drawing verification. All drawings are checked by the verifier after the drafting check has been completed (hopefully). The quality of the drawings often dictates how much calculation checking is required. When I am the verifier, I require that the calculations be included with the drawings. Even if I do little review of the calculations other than to insure readability, this forces the design engineer toward logical arrangement and filing.

 

[BAretired]

I started with a firm in 1956 who had a checking department. After nearly a year in the drafting department, I was assigned to the checking department for another six months before being entrusted to perform original calculations. No major job went out without a numerical check verified by the signature of the checker in the appropriate blank on the design notes.

That firm also had a format for structural design notes which was expected to be followed. If it wasn't followed, checking would have been much more difficult. I recall disliking the task of performing numerical checks on other engineers' design notes and I felt it was not the most effective way to avoid glaring errors in design. Nevertheless, a good many mistakes were caught and I would have to admit that it was somewhat effective.

In two subsequent firms, there was no checking department and everyone more or less followed his own preferences insofar as design notes were concerned. Some of those notes defied clarity or readability.

When I started my own firm, I was the only one doing structural design, so I reviewed my designs from the drawings, usually doing approximate calculations without reference to design notes, although this sometimes led to a more thorough review of my design notes.

Throughout my years as a structural engineer, I have used a format for design notes almost identical to the one I learned in those early days at my first job. The reason for that is that I thought it was a good format which facilitated finding the design of a particular element long after the work was done. By the way, that firm is still going strong although the original partners have died.







BA

 

[bolt45]

OK, sounds like there isn't a lot of checking occurring. That's kind of disheartening for a young engineer to hear. I can see how time constraints, tight budgets, competing deadlines etc. are constantly working against you, but I think some time should be aside for overall sanity checks, particularly from computer output.

I can understand that most major errors won't pass the sight test. You get suspicious when you a W12x19 beam spanning 40 feet or something like that. Even most steel fabricators will flag something like that. But it also seems like there are plenty of errors that go beyond what looks right, particularly in connection design or lateral design. It seems like you should at least be diligent about trying to check atypical design features and other things that aren't so obvious.

I would think the level of checking should also be commensurate with the magnitude of the project. You can probably eyeball the design of a single story wood structure in a few minutes to know whether or not it is safely designed. On the other hand, I would hope there is a rigorous amount of checking done to verify the design of a high-rise building or a long-span bridge.

 

[271828]

I worked in one office that checked calculations, and that process was a joke. Checker: "Here, look, I found that you forgot to add ## psf for [whatever] load." Engineer: "Look, I fixed it. See where I had ## psf too much in my superimposed dead load." LOL I don't think I ever saw anything productive coming out of that process.

Also, if the job is nontrivial, then there it is impractical to have someone go back through and check someone else's calculation notebook. To do that _well_ would take a good chunk of the time required for the calculations. The checker barely figures out what's going on by the time runs out for the checking process. For a trivial job, there's probably not enough fee to design it, much less bring someone else in to look at it also.

An experienced engineer must go over the drawings to see if the overall concept and sizes make sense. For example, if someone has designed a lot of composite floors, he should be able to look at a beam or girder size and tributary area and get within a few sizes without running one calculation. He can keep a big picture view while verifying all of the member sizes, without getting bogged down in whether the guy used 22 psf or 18 psf in his roof dead load, or picked this or that V off the wind map.

 

[pittguy12]

Check calculations? My boss hardly does calculations because he has been in it so long and already has his 'feel' for what works!

Yes, it's frustrating for a young guy which is why I am not satisfied with where I am. There is no way for me to learn to get to this level of 'feel' without first knowing that my long hand or computer analysis calculations are accurate.

As a company, we check drawings and specifications in detail but rarely take any time for calculations. Most of that is left up to the individual responsibility of the engineer.

I have gone to my boss and asked him to check my calculations a few times. He usually tosses my notes aside and does his own set of calcs (never more than a 1/2 page) and tells me either yes or no...sigh.

 

[RFreund]

Pittguy - I can relate but I'm not sour about this as it has forced me to turn to textbooks, google, eng-tips, etc. to ensure my calculation and methods are sound. I think it forces you to really learn as opposed to someone showing you how to do it and you don't think beyond this. But I do agree, it can be very frustrating at times.

EIT

http://www.HowToEngineer.com

 

[Hacksaw82]

While I'm not surprised on what everyone is saying about checking (its the same experience at my office), something pittguy12 said got me thinking.

While it may be disheartning as a young engineer on your bosses 'feel' for structures, this is something that comes with time. I'm only five or so years into practice, but I found this feel, for me, was developed on my own time. I didn't have time during the 9 to 5 (or 8 to 6 In reality) to spend time getting a feel for things. Instead I got this on my own time, going over old lecture notes, creeping on this site, and doing my own sanity checks.

If a young engineer really wants to 'get' structures as a designer, unfortunately the time will have to be spent outside of work hours. With plug and chug, push a button, analysis programs and design sheets, the fees are no longer there for us to learn on the job. The old guys got to feel out their designs, collecting loads, using simplifications via hand methods. I really believe this was a better way to learn, but alas those days are long gone. It's quicker, faster, cheaper these days.

I don't mean to hijack the thread, or hate on pittguy's comments, but the discussion got me thinking about the ways the profession is changing. How much more can market forces squeeze out of our profession? At some point diminishing fees, and professional ethics need to come to a common point, but how we get there is a mystery to me.