Engineering calculations as a deliverable: standards and references

[LT Judd]

TL;DR Summary

Question on the protocols and good business practice for referencing of assumptions and methods used . Are certain methods of calculation mandated by standards. Also on the customer side what are the expectations for reviewing engineering work.

My question relates mainly to mechncial engineering but I guess the general principle may apply elsewhere. Up until now I have mainly been an engineer on the customer side (marine and offshore) , reviewing contractor reports, "sense checking" them and general engineering firefighting and troubleshooting. But I recently moved to a consulting firm that does a great variety of things and may be required to produced engineering reports as a contract deliverable in the future.

I know that in some cases such as ASME pressure vessels code and also marine claissification rules , there are actually set formulas and calculations you should use. However in other cases , it doesn't seem so formalised. I just have a large collection of rules of thumb, excel workbooks and notes,old textbooks and some refence books like "machineries hand book". I wonder does this suffice when producing engineering reports as a deliverable. I am not talking about designing bridges or anything, its more like small process and mechancial investigations in exsiting plant.

Are there mandated steps to follow for calculating things, such as valve and relief valve sizing, heat exchanger sizing, orifice plate sizing.

Of course if it is stipulated in the contract , In my experience sometimes the customers don't really know what they want exactly, so you sometimes need to guide them. I always tried to go to some national or international standard or code of practice , but in the past I was on a salary and my "customers" were internal, so now I also have to mindful on how much time i spend doing that.

I know this may depend on national regulations , so any answers from European or Anglosphere context would be welcome.

Also from the customer side - how deep do customer engineering managers usualy go when reviewing contracator reports? I asked for guidance on this when I was at an oil and gas firm but never really got a satisfactory answer. I got the impression that most managers didnt spend too much time looking into them , unless some thing went wrong later on.

 

[anorlunda]

I know that in some cases such as ASME pressure vessels code and also marine classification rules , there are actually set formulas and calculations you should use. However in other cases , it doesn't seem so formalized.

I'm sure that the formality varies. But pay close attention to the text nuances also.

Industry norms are separate from the standards, but they are also something you should pay attention to.

Also from the customer side - how deep do customer engineering managers usually go when reviewing contractor reports?

Your scrutiny, customer's scrutiny, and scrutiny of the attorneys and the jury in case something goes wrong is what really counts.

You need to be able to defend your work against attack by others.

I recall a lawsuit about a power line that fell on a pedestrian. The case was won, when my colleague testified that, "The code requires a design that equally protects workers and the public." That's not a formula or a formality. It is hard to say what it does mean. But it won the court case. I cite that because it is an example where the non-formula part of the code became important.

 

[DaveE]

I got the impression that most managers didnt spend too much time looking into them , unless some thing went wrong later on.

I think they've hired you because they can't, or don't want to, do the work themselves. So, I agree, the best you'll get from the customer is a cursory sanity check, probably not even that.