recently I needed to design a circuit to perform a really quite complex movement detection system for our camera which would be able to detect when a car was entering the field of view of a camera but which would be immune from small objects moving around in the field of view or the camera moving about on the pole when the wind blew.So I came up with a system which I thought would work, I drew it out in the form of block diagrams, drew a state transition diagram for it,timing daigrams, coded the vhdl implemented the design in the FPGA and then tested it. Whem my boss asked me how it worked I didn't show him the VHDL or the gate level schematic beause those would have been meaningless to him, I showed him the block diagrams and the timing diagrams.From those my boss made a patent application and he never asked to see any more detail all he needed was to see it working and have an overview of how it worked.