Case-based Decision Theory And TRIZ: A Coupling For Product Conceptual Design

Speed to market and innovation are two of the most important attributes that enable amanufacturer to be competitive. These two attributes can be contradicting, forcingcompromises. Despite this, there exists one common activity which can benefit bothattributes–optimize the decision-making process, which can satisfy rapid design andinnovative design simultaneously. Decision-making occur in many places within the designprocess which is made up of task clarification, specification definition, conceptual design,and embodiment design. Within this process, conceptual design is the phase wheredecision-making and creativity can play an important role. Product conceptual design is asystem work flow where specification of the design is the input and the conceptual designscheme of product is the output. The essence of product conceptual design is to acquireinnovative design scheme of new products, and it will effect the quality and the marketcompetitiveness of the final product. The main purpose of the research of productconceptual design is to standardized, formalized, and systematized the procedures, thussupporting designers to develop an innovative product which has a high quality and meetscustomer needs at the lowest expense of the time and the cost. This paper will develop thecustomer-driven product conceptual design process model by regarding the conceptualdesign process as a series of decision-making process, and mainly comitted to optimizerelated decision (Technical decision) problem resolution during the product conceptualdesign, thus helping designers rapidly formulate innovative design scheme for the newproduct development.The paper proposed a product conceptual design process model–QCTIS. QualityFunction Deployment (QFD), Case-based Decision Theory (CBDT), Theory of InventiveProblem Solving (TRIZ), Image-Scale, and Solidworks are integrated into the process model.Specifically, a questionnaire design mechanism by utilizing knowledge-evelutionary lawsand lines,40innovative principles, which come from TRIZ, to excavate unperceivablecustomer needs was firstly proposed. The mechanism is influenced by TRIZ as well as theKano model to evaluate customer needs. Then, a CBDT-based problem resolution modelto support general decision-making during product conceptual design, accordingly somemethods used in the model were discussed, especially attribute scope determination related to similarity evaluation and similarity functions of each single attribute. In addition, based on theprocess of CBDT-based problem resolution model and the contradiction matrix comesfrom TRIZ, a CBDT-TRIZ model for rapidly undertaking innovative solution generationare proposed. Finally, the proposed process model QCTIS also utilizes QFD to translate customerwants into relevant engineering design requirements and thus formulating the design specification,and Image Scale to offer an orthogonal coordinates system to aid evaluation.Through some actual product designs, some software were developed based on theproposed product conceptual design process model, such as the tool for questionnaire design basedon evelutionary lines and40innovative principles, the tool for general decision problemresolution based on CBDT, and a tool for the application of the CBDT-TRIZ model. The feasibilityand effectiveness of the research result can also be proved by these tools. In addition, a―cordlesshand-tool design‖case study was developed to validate the new process model.