12ME4710
PRODUCT DESIGN AND DEVELOPMENT
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Objective(s): To learn knowledge on design of product and their specifications. UNIT – I INTRODUCTION 09 Hrs. Design theory, design materials, human factors in design, man-machine system, applied ergonomics, characteristics of successful product development, challenges to product development. UNIT – II PRODUCT SPECIFICATIONS 09 Hrs. Establishing the product specifications- target specifications -refining specifications, concept generation - clarify the problem - search internally - search externally - explore systematically. UNIT – III PRODUCT ARCHITECTURE 09 Hrs. Concept selection- screening - scoring, product architecture - implication of architectureestablishing the architecture - related system level design issues. UNIT – IV INDUSTRIAL DESIGN 09 Hrs. Need for industrial design - impact of industrial design - industrial design process management of industrial design process - assessing the quality of industrial design design for manufacturing - cost considerations, impact of DFM decisions on other factors. UNIT – V PRINCIPLES OF PROTOTYPING AND ECONOMIC ANALYSIS 09 Hrs. Principles of prototyping - planning for prototypes - economics of product development projects - elements of economic analysis - base-case financial model - sensitivity analysis - influence of the quantitative factors. Total Hours: 45 Hrs. Text Books: 1. Karal, T.UlrichstevenD.Eppinger, “Product Design and Development”, McGraw Hill, International Editions, 2003. 2. George Dietor, “A material and processing approach”, McGraw Hill ,2000. References: 1. Moustapha I., “Concurrent Engineering In Product Design And Development”, New age International Pvt. Ltd., 2006. 2. Chitale A. K., R. C. Gupta, "Product Design and Manufacturing”, - 2007. 3. Chitalagupta, “Product design and development”, PHI learning, 2013. 4. Boothroyd, “Product design and development”, book world, Bombay, 2013.
UNIT – I
INTRODUCTION
Product design Product design is the process of creating a new product to be sold by a business to its customers. It is essentially the efficient and effective generation and development of ideasthrough a process that leads to new products. The essential requirements of a good product design are listed as follows: It must optimally perform its main function (task). It must be easy to repair at a low cost. It must be very reliable to use. It must follow principles of aesthetics. It must be a durable one. It can be easily produced in large numbers at minimum production cost. It must be simple to produce and use (handle). It must also be compact. Conceptual design is to develop concepts to meet design specifications. Detailed design determines all detailed parameters including dimensions, tolerances and other design parameters of all components where a product is described by engineering drawings or geometric models. Configuration design refines design concepts to concrete product architectures and components.
Product development Product development is the set activitieslike Perception of a market opportunity Production Sale Delivery of a product.
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Characteristics of product development depends on Product quality Product Cost Development time Development Cost Development Capability.
Idea generation Idea screening Concept development & testing Marketing Strategy development Business Analysis Product development Test marketing Commercialization
• Morris Asimov proposed 7 phases of design 1. Conceptual Design 2. Embodiment Design 3. Detail Design 4. Planning for Manufacture
5. Planning for Distribution 6. Planning for Use 7. Planning for Retirement
DESIGN MATERIALS
Material selection is a step in the design process of any physical object. In the product design, the main goal of material selection is to minimize cost while meeting product performance goals. Stages of Materials Selection Analysis of material performance requirements Creating alternative material and process solutions for the optimum concept Initial Screening (Ashby’s method of screening – Density Vs Youngs Modulus)
Use the critical requirements of each part to define the performance requirements of the material. Start with all materials available and narrow down the choices on the basis of the rigid requirements. Selection of Optimum Solution Use the optimum materials and matching manufacturing processes to make detail designs. Compare alternative combinations taking into account the elements of cost. Select optimum combination of design-materialmanufacturing process. The selection of materials for designing a product depends on following requirements. o Service requirements– sustainability, resistance to service conditions o Fabrication requirements - material’s melting point, density, moisture content, porosity, and surface texture, dimensional stability, corrosion resistance, adequate strength, hardness, toughness, heat resistance and dissolution o Economic requirements – sustainability, Aesthetics, Product Cost o Reliability requirements The selection of materials depends on the following properties Physical properties - (material’s melting point, density, moisture content, porosity, and surface texture); Chemical properties (resistance to corrosion and dissolution); Thermal properties (heat conductivity, heat resistance);
Electrical properties (materials’ conductivity and resistance to electrical charges); Acoustical properties (materials’ reactions to sound), and Optical properties (materials reactions to light) HUMAN FACTORS IN DESIGN Human factors are basically a rigorous, systematic, and data based science. One human factors exercise is called task analysis. Task analysis is a simple, step-by-step description of human interaction with a device. The analysis describes what the user is expected to perceive (see, hear, feel, etc.), understand, and physically manipulate (press, move, etc.). The discipline of human factors engineering focuses on the combination of user- and device related problems.
MAN-MACHINE SYSTEM Man–machine system is a system in which the functions of a human operator (or a group of operators) and a machine are integrated. The human machine systems consists of three main systems First component: is the human component which includes all human characteristics, like anatomical, physiological and psychological elements. Second component: is the machine component like chairs, tools and equipment with which the human-being interacts Third component: is the environment, it is the place and the circumstances in which the work is carried out and it includes physical and social aspects
Classification of Man-Machine Systems:
Depending upon size and complexity, man machine systems are of following three types: (1) Manual Systems: They are essentially man directed systems. These are flexible in nature and small in size. Simple tools and equipment are used and the efficiency is dependent upon the human factor. A large variability is possible in a manual system as every worker may select different method to do the same job. (2) Mechanical Systems: They are more complex and inflexible in nature than manual systems. The machine component is power driven and human activity is information processing, decision making and controlling occasionally knows semi automatic systems, they have components which are well integrated. This is the feature which renders these systems rather inflexible. An automobile and a machine tool operated by driver or operator are good examples of his class. (3) Automatic Systems: A complex system in which all operational functions are performed by automatic devices is known as automatic system. Operational functions are sensing information processing decision making and action. It is completely inflexible in nature and cannot be adapted to uses other that the one for which it has be designed.
APPLIED ERGONOMICS It is the application of the data and principles of human factors to the specification, design, evaluation, operation, and maintenance of products and systems that are intended for safe, effective, satisfying use by individuals, groups and organizations.
These are classified into reducing stress, designing the machines, matching the job – demands with the people abilities and improving the people’s knowledge about their environment. Two concepts are used 1- Fit man to job - like pilot who drive fight airplane (this need highly qualified person) 2- Fit job to man - like carrying objects (it does not require much training)
CHARACTERISTICS OF SUCCESSFUL PRODUCT DEVELOPMENT
• Product quality – How good is the product resulting from development? – Does it satisfy customer needs? – Is it robust and reliable? – Product quality is reflected in market share? • Product cost – What is the manufacturing cost? – It includes capital equipment and tooling? • Development time – How long did the Product Development effort take? • Development cost – How much spent in PD effort? • Development capabilities – Did the team/firm acquire any experience for future projects?
Challenges to product development • Trade-offs: An airplane can be made lighter, but this action will probably increase manufacturing cost. One of the most difficult aspects of product development is recognizing, understanding, and managing such trade-offs in a way that maximizes the success of the product. • Dynamics: Technologies improve, customer preferences evolve, competitors introduce new products, and the macroeconomic environment shifts. Decision making in an environment of constant change is a formidable task. • Details: The choice between using screws or snap-fits on the enclosure of a computer can have economic implications of millions of dollars. Developing a product of even modest complexity may require thousands of such decisions. • Time pressure: Any one of these difficulties would be easily manageable by itself given plenty of time, but product development decisions must usually be made quickly and without complete information. • Economics: Developing, producing, and marketing a new product requires a large investment. To earn a reasonable return on this investment, the resulting product must be both appealing to customers and relatively inexpensive to produce. • Creation: The product development process begins with an idea and ends with the production of a physical artifact. When
viewed both in its entirety and at the level of individual activities, the product development process is intensely creative. • Satisfaction of societal and individual needs: All products are aimed at satisfying needs of some kind. Individuals interested in developing new products can almost always find institutional settings in which they can develop products satisfying what they consider to be important needs. • Team diversity: Successful development requires many different skills and talents. As a result, development teams involve people with a wide range of different training, experience, perspectives, and personalities. • Team spirit: Product development teams are often highly motivated, cooperative groups. The team members may be collocated so they can focus their collective energy on creating the product. This situation can result in lasting camaraderie among team members.
