I want to have a software which works like a business rules engine to take varied inputs and lets me define the logic graphically and on the fly for processing these inputs.

The project is supposed to allow the user to define inputs, define processing logic and also define the outputs just like a business rules engine does take for example a recangle where Inputs are Length, Width Business rules are 1) Area = Length x Width 2) Perimeter = 2 x (L+B) whereas in case of a circle Inputs is Radius Business rules are 1) Area = 22/7 x Radius x Radius 2) Perimeter = 2x 22/7 x Radius