If you haven’t done so already, you really need to check on these cool tools. The first one is called Parameter Design, and is like Robust Design on steroids! It helps you take a multi-input / multi-output model and find which of many possible good input setting combinations gives really good output results even when the inputs vary according to their statistical distributions! No kidding!
And right behind it is Statistical Tolerance Allocation. Big bucks are wasted in many designs because of poor tolerance design for parts and components. This tool helps to see how changing the tolerance of inputs can affect the change in the output metrics, such as defects per million, etc.
You probably don’t want to “try this at home” unless you enjoy doing many partial derivatives and maybe Taylor series expansions, and maybe a few eigenvalues here and there (I love this stuff!). But I would recommend software. Push a button or two and you’ve completed a few million simulations! Cool stuff. I really like QuantumXL from Sigmazone.
I feel like I need a cape and mask…