A design perspective of mechanical function and its object-oriented representation scheme

The purpose of this paper is to present a functional schema which can be used to develop computer tools to assist designers during the early stages of the mechanical product design process. The schema is based on an analysis of the meaning of function. Five main types of mechanical function are described: performance, assembly, manufacturing, marketing and maintenance. The paper focuses on the specification and representation of performance functions. These are defined using a natural language, which is an extension of the verb-noun pair technique. Three levels of performance functions are identified: overall, embodiment and geometric. The relationship between these levels of functions and the physical structures required to implement them is discussed in detail. An architecture to implement the schema using object-oriented technology is described. A research prototype based on this architecture has been developed in the programming language Incr Tcl/Tk.