PRODUCT DESIGN PRINCIPLES Prof.dr.ing. ȘtefanGHIMIȘI, Constantin Brâncuși University of Targu Jiu, ssghimisi@gmil.com Dana NICULA, Dunărea de Jos University of Galați Abstract.Paper aims to present both the methodology for the design of a product and product design methods. It presents the theory of inventive problem solving (TRIZ), witch with its search concepts becomes an application of rules and laws from "experimental" concrete data abstraction. TRIZ role is to generate ideas carrier solution. Keywords: design, product, artefact, innovation 1. PRODUCT DESIGN METHODOLOGY Creative activity, based on expressed needs and existing knowledge, aims to define a material or immaterial object, called artifact that satisfies these requirements and that can be achieved can be defined as industrial design product (engineering design). Concept is key to the development of a new product design activity, is the transformation of an invention into innovation. To define design we must consider in advance the terms of the invention of innovation and scientific discovery. The innovation is defined as: novelty resulting from an invention, produced on a large scale and launched on the market (Freeman, 1983); processing of a new product ideas in a new operational procedure, or in an action with regard to a service office (Fracasti, 1994); correspondencebetween a real need or potential market solutions achievement (INSA, 1998). The invention is a new technical principle and / or a new technical means implementing a particular function (Freeman, 1983; Kline and Rosenberg, 1986) [1], [2]. Discover means to reveal, which explains that the object discovery already exist can be searched and can be found. Inventing on the contrary, is to produce something that does not exist yet. Scientific discovery is the result of the search (research), while the invention is the result of a design! There can be no invention without conception, design enabling the transformation of an invention into an innovation. Concept of a product is defined as all the activities and processes that allow transition from the idea of a new product release information allowing production to ensure its use and maintainability. Development of a product is defined by all the activities of creation and communication of information witch transforms market data into information and technical opportunities for production - models, specifications, prototypes, designs, programs, etc.. 222
A product design methodology covers the study of the principles, practices and procedures of design. It includes: Work and study ways of thinking of product developers; Implement appropriate structures for the design; Development and implementation of new methods, techniques and procedures; Analyze the scope of knowledge of design and their application to solving design problems A design approach can be structured around three logics of action (Asimov, 1962) [3]: divergence - action aimed at increasing border design situation to increase research space solutions; processing - proceedings of building a structure of a model of a solution, from the logic of the results of divergence; is a phase of discovery and creativity; convergence - the action of progressive reduction of uncertainty due to the multitude of possible solutions, in order to select the most satisfactory solution. In relation to the two canonical forms of reasoning, analysis and synthesis, divergence appeals to analysis, while transforming and convergence mobilizes particular conceptors synthesis capabilities. Different design patterns can be classified into three categories: prescriptive models, which aim to propose a design procedure; descriptive models, which aim to highlight the activities of design; computational models that have the perspective of integrating numerical and qualitative techniques of artificial intelligence. Another typology of design patterns is based on five principles (Perrin, 2001) [4]: design as hierarchical succession of different phases; iteration of design as an elementary cycle design; design as emergent phenomena of self-organization that builds on interaction design group; design as a cognitive process; concept as a form of conversation. One of the most popular models is the model of Pahl and Beitz design [5]. It is based on the concept of hierarchical sequence of phases (Fig. 1), the dominant logic of action being convergence. Definingthe problem Preliminary Concept Preliminar y Concept Detailed Concept ARTEFACT Fig. 1. Design phases [5] 223
The origin of any new product is a specific problem to be solved and a goal to reach. The first phase is to establish design specifications or technical specifications and economic want. Next phases is to understand the concept as a process of materialization edge of the solution reached or a transition to a function (abstractform) to a solution (concreteform). In the first phase of preliminary design (conceptual design) is chosen object concept from a functional analysis and a study of the technical alternatives available for each function and sub function. The conceptual design phase (designembodiment) purpose is to determine the shapes and sizes of the artifact. The detailed design phase (detail design) provides constituent components, prepares the necessary documents and prepares their manufacture to the supply. This type of model describes the concept as a linear descendant, many interactions (feedback) occurring between phases and intermediate stages. One of the criticisms leveled at Pahl and Beitz model [5 ] is that it does not account for the many alternatives that are generated and analyzed during the design process. 2. PRODUCT DESIGN METHODS Design methods means all procedures and techniques used in the design. We have two categories [6]: systemic methods according to which model artifact should be designed. analytical methods determining step by step artifact, analyzing reality; Although the methods are complementary, we can highlight the differences between them (Table 1). Table 1. Comparison of analytical methods and system design MethodsSystemic The artifactisbuilt The issueneedstobe put right, theprocessis important. The artifactiscomposedbyarticulatingandlinkingel ementstogetherandfully SynthesisandInduction The principle of intelligentaction Model building canbereduced Validationbytransformingreality (simulation) transdisciplinaryeducation Parallelism, more reasoning, more criteria Consider theconflictsandcontradictions AnalyticalMethods The artifactisdetermined Looking for solvingthe problem, investigatingthecauses, theresultmatters. The artifactisdecomposedintocomponentstobeisola ted Analysisandinference The principle of leastaction Prioritymathematicalandquantitativemethods Validationby experimental testing DisciplinaryEducation (juxtaposed) Linearity, onereason, onedecisioncriterion Deletecontradictionstomakereality conform to schema 224
The methods currently used in the product design cycle can be classified into five stages as shown in Table 2. Several observations can be made upon presentation of the main methods of design of a product : none of the methods cited in the concept development phase does not allow or facilitate the research of solutions outside the domain of expertise of engineers design or undertaking to which they belong ; These methods are very effective in the first two rounds and the last; instead stage research ideas and concepts based on psychology are less systematic and non- reproducibility; Sometimes complementary, often too little exploited, QFD, Brainstorming and functional analysis has many attractions and prove to be the most capable means to help businesses looking perpetual innovation, but the key to this lies in the idea, and none of these means come to propose a solution to this problem. Table 2. Design methods used in the innovation cycle Stages Identifyingthe problem Statingthe problem Development of concepts Evaluation Implementation Methods Pareto Law Diagramscause - effect (Ishikawa) Quality functiondeployment (QFD) Octopus (Pieuvre) Functionalblockdiagrams (BDF) Structural analysis (SADT) Brainstorming TreeDiagrams functionalanalysis matrixdiagram multi-criteriaevaluation GANTT PERT Chart To solve the problems of innovation theory inventive problem solving ( TeorijareshenijIzobretateliskihZadatch TRIZ or Theory of Inventive Problem Solving - TIPS ) is considered as a powerful method. Suitable methods of this theory are given in Table 3. TRIZ method [7] combines the advantages of two types of design, reducing psychological inertia that blocks the emergence of new ideas and using knowledge-based analytical means for multiplying the emergence of innovative concepts. Note that TRIZ does not replace other methods, but complementary to place, through their ability to generate ideas bearing solutions. Various means developed in TRIZ can cover the entire preconception cycle of a product or system (Table 4).Figure 2 shows the design methods used 225
Stages Identifyingthe problem Statingthe problem Development of concepts Evaluation Implementation Table 3. Methods used in design innovation cycle Methods Questionnaire Laws of evolution Clarification of technicalcontradiction, Model field-substanceconstruction Clarificationphysicalcontradiction Matrixsolvingcontradictions, Standard solutions, principles of separation PhysicalEffects Ideal final result Functionala nalysis of need Quality functiondeployment QFD FunctionalSpe cification TechnicalSolution TechnicalFunctiona l Analisys Analysis of failuremodes, effectsandtheircriticality Fig. 2. Design methods used 226
Stages Identifyingthe problem Statingthe problem Development of concepts Evaluation Implementation Table 4. TRIZ tools and design cycle TRIZ Means Questionnaire Laws of evolution Clarification of technicalcontradiction, Model field-substanceconstruction Clarificationphysicalcontradiction Matrixsolvingcontradictions, Standard solutions, principles of separation PhysicalEffects, Brainstorming Ideal final result With this method the search concepts becomes an application of rules and laws from concrete data abstraction "experimental ". TRIZ role is to replace the current methods, but the situation is complementary to the generation of ideas carrier solution. TRIZ can be applied to: Research and development of new products and systems by proposing a set of laws of evolution ; Solve difficult problems using a methodology and tools based on solving the conflicts inherent in all technical systems; Identify and treat failures of industrial products and systems. CONCLUSIONS Concept is key to the development of a new product design activity is one that allows the transformation of an invention into innovation. Concept of a product is defined as all the activities and processes that allow transition from the idea of a new product launch information to allow production to ensure its use and maintainability. There are two methods: systematic and analytical though complementary call differs in approach. To solve the problems of innovation, theory of inventive problem solving (TeorijareshenijIzobretateliskihZadatch - TRIZ Theory of Inventive Problem Solving or - TIPS) is considered as an efficient method combining the advantages it has two types of design, reducing psychological inertia that blocks the emergence new ideas and using knowledge-based analytical means for multiplying the emergence of innovative concepts. 227
REFERENCES 1. Kline, S., Rosenberg, N. (1986). An Overview of Innovation. In: The positivesum, Washington, National Academy Press 2. Roozenburg, N. F., Eekels, J. (1995). Product Design: Fundamentals andmethods. John Wiley&Sons 3. Asimov, M. (1982). Introductionto Design. PrenticeHall, EnglewoodCliffs 4. Perrin, J. (2001). Concevoir l innovation industrielle - Méthodologie de conception de l innovation. CNRS Editions, ISBN 2-271-05822-8, Paris 5. Pahl, G., Beitz, W. (1996). Engineering Design. London, Design Council 6. Draghici Gheorge,(2005) Conceptiainovanta, colaborativa, integrata a produselor, Revista de politicastiintei, ISSN 1582-1218 7. Bertoluci, G., Le Coq, M. (2000). Intégration de TRIZ au sein du cycle de conception de produit. Proceedings of The 3 rd International Conference on Integrated Design andmanufacturing in Mechanical Engineering IDMME 2000, Mascle, Ch., Fortin, C. &Pegna J. (Ed.), CD-ROM, Presses Internationales Polytechnique, ISBN 2-553-00803-1, Montréal 228