Usually, the modeling involves those steps :
Fuzzy Description ----(1)----> Clearer Description -----(2)-----> Mathematical model.
Of course, it's not linear and a lot of iteration and re-modeling is involved.
I am looking for resources on the (1) part. How to do the problem discovery? How to ask the customer the right questions? Are there some tools/methods that help with that? etc.
It's more like the soft aspects of modelling and not about writing mathematical equations down.