Energy Based Functional Decomposition in Preliminary Design

This paper presents an energy based approach to functional decomposition that is applicable to the top down design (system to subsystems to components) of mechanical systems. The paper shows that the main functions of convert and transmit are sufficient to focus on the “functional flow” or main energy flow resulting in the specific action sought as a result of the artifact being designed, and can be expanded upon at the lowest level when looking for specific solutions based upon the energy and mass balances and the knowledge within the design team. This approach considers function as a transformation and also fits the approach presented in TRIZ. The standard energy, material, and signal flows are seen as forms of energy flows, and it is only their transformation and transmission that is sought. This simplified approach, coupled with an aspect of control and interaction between a reference state and the artifact or between various components is sufficient to comprehensively describe the system that matches very nicely the value function approach of Miles. Furthermore, as these interactions can be considered as artifact-artifact affordances when considering the artifact for either artifact interaction or within an environment, its relation to the user and to the reference state can be addressed during the design phase, in addition to the functions.