Method of Ranking in the Function Model

At present function analysis is often used for system analysis and concept design development. Function analysis is based on modelling technique and rules of model modification, the most known of which is trimming. Trimming operator suggests system simplifications after each element of it is given a rank. Thus, the core of the trimming is the evaluation criterion.The article compares two known ranking methods (Gen3 method and method of Miao Li) and suggests a new method of ranking of elements in the function model. Exemplary mechanical system design analysis shows how different ranking approaches influence the trimming procedure. The method can be used for CAD/CAM software at the stage of conceptual design for automatic and semi-automatic system simplification.