There are definitely solutions out there which attempt to model flow charts in a generic way.
Things like windows workflow foundation, SSIS, routing in message queues etc.
But in my experience, unless the requirement comes from a technical source. ie IP routing, fail over dns etc where a technical spec for the form of the logic exists. Its best to make your code match the requirement document as closely to the way it describes the logic as possible
You will have holes in the logic and results that seem inconsistent, but your code will meet the requirement, and when the requirement changes in some weird way, you wont find yourself shoehorning it into a clever generic system which expects the logic to be expressed in a particular way.
This usually boils down to a big if block. but it will be easy to read and easy to change