Design factor 'n' in machine design?

Question

What is the design factor 'n' in machine design. I know the formula is loss-of-function parameter/maximum allowable parameter. What does this formula mean physically???

Answer 1

In machine design n is used for any number of variables, including the factor of safety, so the d is probably just to differentiate. Physically the design factor is a measure of how much the structure or machine has been over-designed. During the design process the engineer will determine the worst-case scenario of all parameters necessary to implement the design effectively and if prudent will build the project to meet all worst case scenarios. Realizing that it is extremely unlikely that everything that can go wrong, will go wrong simultaneously, the engineer will determine operating conditions for the design and these will be the maximum allowable parameters.

So the machine has been designed for failure, but it will operate below the threshold. The fraction that the machine is designed to operate below failure is the design factor.