Functional modelling through Function Class Method: A case from DfAM domain

Functional modelling is an essential part of systematic design approaches and is often prescribed in engineering design textbooks. However, function models created with current function modelling techniques often lack formal and repeatable representation, limiting their use in computational reasoning. Therefore, this paper presents a new functional modelling method to support function models' creation with formal and repeatable representation. The key element of the proposed method is a Function Class – a function-modelling element that categorises defined functions on a function block level by specifying operating flow, input and output flows, and integrates primary rules for functional modelling such as conservation law. The formalisation on a function block level reduces the number of morphological errors and provides a theoretical framework for future computational processing of function models. This paper proposes a protocol for developing Function Classes and defines a theoretical function modelling framework through Function Class Method. The development and use of the Function Class Method are demonstrated through the development of Function Classes for the Design for Additive Manufacturing domain as the first step toward a universal function modelling approach.