Monty..

I don't know if there is any one program available that could take all the different possibilities into consideration..I believe that there is a variety of different conditions that would make computer programs inevitable and modeling programs are obviously available..

So ,I have not answered your question ,but have opened the floor to more discussion on the method of calculation and the accuracy of the process..

As a professional engineer I assume you are responsible for the accuracy of your results ,if you put your professional stamp on a project..

Insurance is even carried in many cases by those in the profession to guard against law suits..

But how accurate these estimates ,and that is all they can reasonably be..are ..I don't know..

Good question ..

Portee