Research On The Constructing Method Of Product Function And Modular Structure Based On Function And Affording Set

Chinese manufacturing enterprises now face the challenge that developed countries are guiding high-end manufacturing to go back and other developing countries are trying to seize low-end manufacturing from China. And the change to historical background also add pressure to the enterprises.All the factors ask the enterprises to improve product design ablility.The research results of design methodology are valueable to help improving design ability.Through reviewing the history of design methodology, Systematic Engineering Design Process Theory is found as the most mature theory system. The paper deeply analyzes the conceptual basis and core elements of Systematic Engineering Design Process Theory, and points out that the part of design activity in intent realm has been explicitly expressed based on logic and reason. But other part of design activity in physical realm has not been explicitly expressed by now. So when dealing with the part of design activity in physical realm, designer have to rely on experience and intuition, which increase thinking difficulty and make omission more often to happen.The paper constructs a combined concept basis using "Function" and "Affording set". "Function" is a concept in intent realm meaning "intended behavior", and "Affording set" is a concept in physical realm meaing "possible behavior set". Based on the combined concept basis, the paper constructs a design method theory system which can explicitly express both parts of design activity in intent realm and physical realm.Then the paper researches on constructing function structure and clustering module structure based on "Function" and "Affordaing set".The main research contents and innovation points of the paper are as follows:(1)The paper analyzes different understandings to"Function",and proposes that different meanings of "Function" in fact represent different system levels of conceptual objects to "Function".So the theory system in the paper divides the conceptual objects to "Function" into Goal-level System, Effect-level System and Behavior-level System. Through this way, the paper unifies different meanings of "Function" into "intended behavior".And the paper analyzes the "Affordance" concept from the emerging design methodology, finding that the meaings of "Physical Affordance" and"Perceived Affordance" exist at the same time. Adopting the part in physical realm of "Affordance" concept, the paper define the concept of "Affording set",which mean "possible behavior set".The paper compares "Function" and "Affording set" from different views, and make it clear that the two concepts don’t conflict. "Function" and "Affording set" are compatible and complementary, and the combined use of "Function" and "Affording set" suit to every level system object. The two concepts can be connected through "Behavior" and "interacting pattern", forming the combined conceptual basis of design activity to cover both intent realm and physical realm.The paper proposes a design activity framework based on combined conceptual basis,which can cover different levels of system objects to design activity and can iterate between intent realm and physical realm based on logic and reason.In intent realm, it’s a up-down design process to focus to realize "function" from Goal-level System to Effect-level System,then from Effect-level System to Behavior-level System. In physical realm, it’s a bottom-up design process to check "Affording set" from Behavior-level System to Effect-level System,then from Effect-level System to Goal-level System.The two parts constitute a up-down-bottom-up iterated design activity framework.(2)The paper proposes a function structure constructing method, which alternates from "Function" view and "Affording set" view and includes both functions to physical product and human activity.Do reverse thinking first to explore the needed necessary condition to achieve the expected state, therefore draw out reverse function chain.Then based on reverse function chain,try to think about all possible behaviors when the function chain carries out, seek sub functions to deal with the unintended behavior and add the sub functions into the function chain,forming deduction function chain.All reverse function chains are combined into reverse function structure which reflects the main body of function structure to meet customer needs.And all deduction function chains are combined into deduction function structure which reflects overall function structure.The overall function structure covers both sub functions to physical product and human activity.(3)The paper proposes a multiple matrix method to cluster the module structure of generalized, which takes all Goal-level System, Effect-level System and Behavior-level System into consideration.The module structure formed by this method covers both physical product and human activity, also covers both intended behavior and unintended behavior. And the interactive relationship among solution elements from all requirement, function ang structure view will be reflected into the module structure.