The problem is, we have some very complicated business processes, the code for which does not cover all possible scenarios. Our management of this logic is sporadic, uncomprehensive, unmethodical, reactively patched, etc. I want to find a methodology to allow us to cover all scenarios and automatically generate unit tests.
My current idea is, our BA would be able to create a flow chart, and we devs could export all the pathways and convert into unit tests.
In terms of code, I would like a single master function with all the inputs (~50) that would determine all the expected outcomes, rather than having logic scattered around incoherently.
Does anyone have any similar experience or ideas?

Up until now, I’ve been using spreadsheets with columns for each of the inputs and rows for all possible scenarios, but this is difficult to manipulate and results in huge numbers of rows so is only suitable for up to about 10 inputs.