There comes a time when performing engineering analysis that the analyst will not be able to acquire all of the information he needs in order to begin or continue the development effort. Or, the boundary conditions are not well defined, material properties that the analyst may require are not as complete as desired, or any number of things that shed some doubt on the validity of the end result – which is an analysis that as closely as possible reflects the conditions the customer desires – analysis paralysis sets in.
The solution is really quite simple, but there are those out there in the engineering analysis community who may throw up their hands and say something to the effect, “I don’t have the numbers I need to continue my analysis. Unless I get this or that figure, I have to stop work.” From a purely analytical perspective, the person making the statement may be absolutely correct. The problem is, the task must be completed, and stopping work because the result may be something less than desired is usually not a reasonable option.
So, what is to be done? As with all things, we do the best we can with what information and tools we have, and with the understanding that analysis is an approximation of reality. It’s not going to be perfect.
Say, for example, the material property you need at a certain temperature is not available. Material properties can be estimated from many sources. This figure may be able to be interpolated or extrapolated from existing data. Or, a material that is very similar to the one being used in the design could be compared with the actual part material data, and the material property estimate completed. Yes, it will not be quite as good as if you had the number for the specific material at that specific temperature, but it may be a pretty good estimate and allow the project to continue. I am not advocating guesswork by any means. The general idea is to determine a method for acquiring the numbers you need, make note of it, and proceed ahead.
Norman T. Neher, P.E.
Analytical Engineering Services, Inc.
Elko New Market, MN
www.aesmn.org