Design and Manufacturing Page 1Chapter 1 DEFINITION OF ENGINEERING DESIGN 1.1 Introduction: The economic future of India depends on our ability to design, make and sell competitive products. Excellent design and effective manufacture are the pre-requisites of a successive industry. There is a general impression that the quality of Indian products can still be improved. The fact that consumers have lost their confidence on Indian-made products cannot be denied. This problem can be solved only by designing and manufacturing better products through improved methodology. Keeping this in view, the subject “Design and manufacturing” purpose to present the methods and procedures of design and manufacture. Although engineers are not the only people who design things, the professional practice of engineering is largely concerned with design. It is usually said that design is the essence of engineering. The ability to design is both a science and an art. The science can be learned through procedures developed by eminent scholars. But the art can be learned only by doing design. • Types of Products A product is the tangible end result of a manufacturing process and is meant for satisfying human needs. The product can be classified as follows: • Convenience goods These are less expensive and are clustered around shops and restaurants. These can be purchased at consumer's convenience. E.g. Cigarette, Candy, Magazines etc. 2. Shopping goods These are expensive and people buy it less frequently. E.g. Jewellary garments etc. 3. Specialty goods These are purchased, taking extra pain. E.g. Rare objects like stamps. 4. Industrial goods. These are items used in the production of other items. Eg. Raw materials. Another way of classifying products is into, (a) Continuous Products, and (b) Discrete products The continuous products are those which are produced in a continuous fashion. For example, plates, sheets, tubes and bars etc are produced in very long lengths, and then these are cut into desired lengths. On the other hand, discrete products are produced one after another, each in separate units. On the basis of the output product, the Industry is usually named as continuous industry and discrete industry. 1.3 Requirements in a good product • Customer Satisfaction • Profit How to achieve customer satisfaction? -The product should function properly. -It must have desired accuracy -It must have desired reliability -It must be easy to operate -It must be serviceable -It must make minimum space utilization -It must withstand rough handling -Pleasant appearances. This is due to lack of interaction between the different departments. 1. good in appearance. The customers ‘throw' their needs to marketing department. in many instances. Design department may conceive a design and hands it over to the manufacturing sections. orally. This situation led to over-the-wall design process. Unfortunately. “Design is an act of collecting all pertinent information for the production of goods and services to meet some human need”. The Engg. The design of any component includes two things. How can it be profitable? -It must be easy to manufacture -The raw material must be cheap and easily available -The manufacturing process has to the decided on the basis of quantity to be produced -It must use standard parts -It must be easy to pack and distribute.4 Definition of Design: (S ‘94) Designing is such a vast field that it is defined in several ways. and will give satisfactory performance for an adequate life. Even for a large project such as the design of a ship or a bridge. 1. Marketing. The manufacturing department interprets that design and makes the product according to what they think suitable. one person could not handle all aspects of design and manufacturing. The process design involves developing methods of manufacture of the products so that the component can be produced at a reasonably low cost. . By the middle of the 20th century products and manufacturing processes became so complex that. • Product design • Process design The product design involves the development of specification for a product that will be functionally sound. as shown by wall. this single direction over-thewall approach is inefficient and costly and may result in poor quality products. The marketing department may throw the customer needs to the design department. There was only one-way communications between Customer. Materials and manufacturing processes to manage all aspects of the design and construction of the project. In this method each functional departments were separated from others. Thus. Various definitions of designing as pronounced by well-known designers are “Design is that which defines solutions to problem which have previously been solved in a different way” “ Design is the conscious human process of planning physical things that display a new form in response to some pre-determined need”. Design and production department. This period is referred to as the period of design by single person in the history of design. often what is manufactured by a company using over-the-wall process is not what the customers had in mind. Engg.5 History of Design Process • Design by Single Person • Over-the-wall design • Simultaneous Engineering • Concurrent Engineering • Integrated design and Manufacture. In olden times one person could design and manufacture an entire product.-Reasonable price. one person had sufficient knowledge of the Physics. Although many of the tools are computer-based. For making original designs.g... converting mechanical watches into a new shape.g. it is also called new design or innovative design. Thus. • Original Design Here the designer designs something that did not exist previously. • Variant Design This type of design demands considerable scientific training and design ability. Discuss the role of creativity in the design process (S'94. In this case.. 97. This philosophy emphasized simultaneous development of the manufacturing process. at all stages of product development. With the advent of computer technology. drastic changes have taken place in the field of design and manufacturing. FMS etc. design tools. efficiency and productivity..…………get first preference in design Ans. E.By the early 1980's the concept of simultaneous engineering emerged. This was accomplished by assigning manufacturing representatives to be members of design team. QUESTIONS • How can you explain the term design? Explain the process of mechanical design. knowledge and creativity are essential. Here a new technology is adopted. concurrent engineering is 80% company culture and 20% computer support. E. S'94) • . a lot of research work. In the 1980's the simultaneous design philosophy was broadened and called concurrent engineering. This system makes a good use of technologies such as CAD/CAM.2 On the basis of the nature of design problem. the designs are broadly classified into three types • Adaptive Design (W 95. The result was a completely integrated design and manufacturing system.. and techniques and information about the product and the processes used to develop and manufacture it. much design work is still done with pencil and paper. these are also called creative designs. Functional requirements (S'93) • Explain the meaning of • Conceptual design • Functional design (iii) Production design. These are called adaptive designs .1 The design can be classified in many ways.. design. CIMS is necessary for better quality. process and equipment etc. This type of design needs no special knowledge or skill. 8M) • The design of product is ….the goal was the simultaneous development of the product and the manufacturing process. On the basis of knowledge. A company thinks of new design when there is a new technology available or when there is enough market push. converting mechanical watches into quartz watches. The computer integrated manufacturing systems (CIMS) moves towards the ‘Factory of the future'. Give suitable examples for each. In fact. by adopting a new material or a different method of manufacture. 98 ‘00) • Variant Design (S 97. Tools and techniques connect the teams with the information. product specification.. In concurrent engineering the primary focus is on the integration of teams of people having a stake in the product. skill and creativity required in the designing process. Since this type of design demands maximum creativity from the part of the designer.customer expectations.. 2. in order to modify the existing designs into a new idea.. 99) • Original Design • Adaptive Design In most design situations the designer's job is to make a slight modification of the existing design. (S'99. though the designer starts from the existing designs. A short definition of concurrent engineering is the simultaneous progression of all aspects. so that they could interact with the design engineers throughout the designs process. the final product may be entirely different from the original product. (S'03) Page 2 CHAPTER 2 TYPES OF DESIGNS 2. design may be classified as . It involves choosing one or more items from a list of similar items. a floppy disk drive and room for two extension boards. . power supply. a main circuit board. Eg. S'02) In this type of problem. We do this by using catalogues. For example. the extension slots must be adjacent to the main circuit board and the keyboard must be in front of the machine. all the components have been designed and the problem is how to assemble them into the completed product. The designer's aim is to find. This type of design is similar to arranging furniture in a living room.• Selection design • Configuration design • Parametric design • Original design • Re-design • Selection Design. a hard disk drive. A laptop computer has a keyboard. Consider the packing of electronic components in a laptop computer. -Selection of a bearing from a bearing catalogue -Selection of a fan for cooling equipment -Selecting a shaft. how to fit all the components in a case? Where do we put what? One method for solving such problems is to – select a component randomly from the list and position it in the case so that all the constraints on that component are met. Each component is of known design and has certain constraints on its position. • Configuration / Layout / Packaging Design (W 97. Keyboard Main Circuit board Extension slots Floppy drive Power supply The different components are shown above. 3m long. If the customer needs a cylinder 0.Let's take keyboard first.3. If a conflict arises. the designer designs something in such a way that the cost of producing the product is minimum. Two potential configurations are shown above. On the basis of the objective or strategy the designs are of following main types. 2. or all the components are in the case. A good designer. under the specified constraints. • Original Design As described in an earlier section. • Production Design • Functional Design • Optimum Design • Production Design In production design .25m long. the manufacturer might lengthen the outer cylinder and the piston rod to meet this special need. Given V = 4 m 3 = r 2 l r 2 l = 1. then. has to consider the production aspects also. • Parametric Design Parametric design involves finding values for the features that characterize the object being studied. money and efforts. an original design in the development of an assembly or component that did not exist before. the following types are important. Most design problems solved in industry are for the redesign of an existing product. The volume is given by V= r2l The tank is described by the parameters. A product designed without keeping all these aspects into account. a production designer is concerned with the ease with which something can be produced. Consider a simple example – We want to design a cylindrical storage tank that must hold 4 m 3 of liquid. Functional design is a way of achieving given requirements. Then we select and place a second component.273 We can see a number of values for the radius and length. the aim is at designing a part or member so as to meet the expected performance level. radius 'r'. 2. we back up and try again. Each combination-values of r and l gives a possible solution for the design problem. that will satisfy this equation. That is. Suppose a manufacturer of hydraulic cylinders makes a product that is 0. • Functional Design W93 In functional design . This procedure is continued until we reach a conflict. It is placed in the front. the first responsibility of the designer is reduction of production cost. • Optimum Design [W 95] It is the best design for given objective function. and length l . It is same as adaptive design. • Redesign The redesign is a modification of an existing product to meet new requirements. and that at a minimum cost. • Mechanical Design • Machine Design . wastes time.but the same may the unproducible or costly to produce.4 On the basis of the field/ area or the domain of design.. Hence. Explain the meaning of • Conceptual design. The assembly has to be designed to meet broad technical parameters and purpose for which it was meant. • Sub-assemblies should be capable of being built separately in order to give maximum manufacturing flexibility. the designer takes into account the variations of such parameters. Distinguish between functional design and industrial design. Discuss the meanings of conceptual design. the external load acting on a body. computers have become an indispensable tool. What are the characteristics features of system design. What are the three main types of design? Give a comparative analysis. In modern design. Generally. the properties of materials etc are liable to vary. technical information and imagination in the design of a structure. analyze and evaluate data etc. Other types of designs are Probabilistic Design Industrial Design Probabilistic Design [S 96] It is a design approach in which design decisions are made using statistical tools. [S0'3] 10. creative design.or machine to perform prescribed functions with maximum economy and efficiency. Computers are largely used in a design office for simulation and prototype study. 5M] 2.• System Design • Assembly/sub-assembly design • Computer aided design • Mechanical Design It means use of scientific principles. Ans. Explain layout design. adoptive design and variant design.. Questions 1. adoptive design and variant design. • Computer aided design [CAD] It is a design methodology in which the designs take the advantages of digital computer to draw concepts. • Standard parts may be used. (ii) Functional design and (iii) production design. Give suitable example of each. [S0'2] Page 3 Chapter 3 DESIGN PROCESS AND ITS STRUCTURES 3. Introduction . assembly/sub-assembly design and component design? Explain briefly with the help of examples. W '97] • Explain the difference between creative design. [S'97] 4. In probabilistic design. • Assembly/sub-assembly design [S 93] In the design of Assembly/sub-assembly the major criterion is the fulfillment of functional requirements. Eng. to solve problems and needs of society. Sciences [W '94] 8. • Machine Design It is the process of achieving a plan for the construction of a machine. • System Design System Design is an iterative decision making process to conceive and implement optimum systems. [W'00. [W'93] 3. [S'93. [S'02 W'98] • Designing for function involves the use and knowledge of ……………. ergonomics and production aspects. The characteristic features are: • The total number of parts used in the design must be minimum. • Flexible parts should be avoided. Industrial Design [W 93] It is the design made by considering aesthetes. as they are easily damaged during handling and assembly.1. which is non-existing yet. In each phase. Requirements of the customers of today's world changes so frequently. 4. whether important or unimportant is the starting point of design. • Design by Innovation Since the traditional design method failed to cope with modern design requirements. 2. If one looks at history it can be seen that most of the tools. money. only after a number of trials.. it took a very long period of time to occur even a slight modification. A satisfactory conclusion can be reached on. In modern design situations the evolutionary methods are not adequate because of the following reasons. How a design is born? In a broad sense there are two methods by which a design comes into existence. But.2.Developing a manufacturable product is not an easy job. He has to ensure the technical and economical feasibility of the product. As a result. Traditional design methods cannot cope with competitive requirements of the modern world.3. Necessity of analyzing complicated interaction of components. an innovative designer faces the following difficulties. • Design by evolution (Traditional Design) • Design by innovation (Modern Design) • Design by evolution This implies the traditional method of design in which the objects and articles that we see around has taken its present form by gradual change of time. Even today this process is being used to some extent. This chapter presents some methods that help achieve quality products. 2. Things changed gradually with the passage of time. Here he tries to solve the design problem in a systematic and orderly manner. only an overview of designing process is attempted here. there is conversion of resources such as time. in the present time. The main reason for this slow evolutionary process of design was the absence of proper information and design data records. However. Needs. any penalty of a wrong design will cost great loss. 3. nowadays almost all designs are made by innovation. 3. equipments. i. developments of a product by following scientific and purposeful effort. talent. 1. He has to design and create something. Due to the above reasons modern design problem cannot be handled by traditional methods. all went through a process of evolution in which designers tried one concept after another. Bicycles. . Rather than making a detailed study. the existence of one product is dependent on another in some way or other. The traditional designing did not consider the interdependence of products. In such conflicting situations. repeated attempts are required to accomplish the aim. He has to make predictions regarding its performance. implements.e. production was on small scale. 3. designer has to make the best decision. The innovative design is entirely different from the past practice of evolutionary design. In the past. They were concerned about only one component /product. Each change was made to rectify some defects or difficulties faced by the users. A designer often comes across several equally acceptable alternatives to meet some end. He has to collect and evaluate information on a product. This approach is similar to analytical problem solving. Here the designer's task is greatly magnified. However. which did not exist yet. calculators. production is on large-scale basis. Thus the penalty of a wrong design was tolerable. materials and other natural resources. 1. All designs are aimed at satisfying some human need. took a long time to acquire their present form. Traditional design lags behind the advanced product & process technologies available today. 5.e. Decision-making is essential for a designer to select one out of several. Features of design process The following features can be observed in a design process. steam locomotives etc. • Iteration • Decision-making • Conversion of resources • Satisfaction of need Design is completed in many phases. But in the modern world. this evolutionary process is very slow. computers. i. In any design process.. 3. Design operations imply the various processes done during designing. Morphology of design refers to the time based sequencing of design operations.5.Notwithstanding the above difficulties.g. Evaluate the alternatives. General Information E. Shigly. 5. The required informations may be broadly classified into two. Information on manufacturer's catalogue Materials science handbook etc. 3. Scientific Laws Information on market trends etc. The best way in which any problem can be solved is to break up the problem and to try for a solution in an analytical method. Establish or convince ourselves that there ‘is' a problem. design operations) a lot of information is required. By analyzing the problem we decide what is actually required from the problem-solver. Morphology means ‘a study of form or structure'. 1. • Formulating a model for analysis purpose.e. The outcome may be in the form of Computer print outs. The logical order of different activities or phases in a design project is called the morphology of design. 3. Or we understand that a solution is needed. 1. Present the acceptable solution. Dieter etc have attempted to systematize the design process.. Or we decide the requirements. Generate alternative solutions. These include • Searching for possible alternatives systems to satisfy a need.E. • Materials selection. Once the designer has obtained the necessary information he can start design operations. This systematized steps in design process is called Morphology of Design . Plan how to solve this problem 3. Problem-solving Methodology Knowingly or unknowingly we follow six basic actions when we try to find solution of any problem.6. 3. 2. 6. J.4. But in order to carryout the above processes (i. Design Process. The design operations give outcome s.Simplified Approach A simplified approach to designing as outlined by Morris Asimow is given below. According to him the entire design process in its basic forms consists of five basic elements as given below. 2 . E. Morphology of Design. This approach of problem solving is also adopted in the Morphology of design.g. etc. there are eminent experts like Morris Asimow. Specific information . . It is a methodology of design by which ideas about things are converted into physical objects. or drawings. 4. If the outcome is sufficient to meet the need. • Check for performance. The arrangement.e. The purpose of evaluation is to decide whether this outcome is able to meet the need. dimensions. the designer goes on to next step. the . otherwise the design operation is repeated Page 4 3. Feasibility Study. tolerances and surface properties of all individual parts are determined. Morphology of design refers to the collection of these time phases. The important activities done at this stage are: • Model building & testing • Study the advantages and disadvantages of different solutions.Next stage is the evaluation of this outcome. Phase 1. is it physically realisable? Is it economically worthwhile? Is it within our financial capacity? Phase 2 Preliminary (Embodiment) Design. The morphology of design as put forward by Morris Asimow can be elaborated as given below. from. This stage is also called conceptual design.7 Detailed Morphology of Design A design project goes through a number of time phases. Also. Here a comparison between the capabilities of the outcome and the need is carried out. rather than the outcome of one's fancy] • Search for a number of possible solutions • Evaluate the solutions i. quality strength. Phase III: Detail Design Its purpose is to furnish the complete engineering description of the tested product. aesthetics etc. This is the stage art which the concept generated in the feasibility study is carefully developed. The purpose and activities during feasibility study are • To ascertain there really exists a need [ie the existence of need must be supported by necessary evidences. A design project always begins with a feasibility study. It consists of seven phases. Hence this method is also called creative design. Phase VII: Planning for Retirement. This is the phase that takes into account when the product has reached the end of useful life. Methods of Innovative Design As we know. Finally. W98. • Specify the requirement in the plant.8. A creative designer is distinguished by his ability to synthesize new combinations of ideas and concepts into meaningful and useful forms. S03] Majority of designs belong to variant design. Phase V: Planning for Distribution The economic success of a design depends on the skill exercised in marketing. • Estimation of production cost. i. A product may retire when • It does not function properly • Another competitive design emerges • Changes of taste or fashion The various steps in this phase are • Design for several levels of use • Design to reduce the rate of obsolescence. • Planning effective and economic warehousing systems. • Planning advertisement techniques • Designing the product for effective distribution in the prevailing conditions. Different activities of this phase are • Designing the packing of the product. The various steps are • Design for maintenance • Design for reliability • Design for convenience in use • Design for aesthetic features • Design for prolonged life • Design for product improvement on the basis of service data. 3. • Planning for information flow system etc. Creativity [S94. systematized and logical approach for solving a design problem. the document containing a sequential list of manufacturing processes. this phase aims at planning an effective distribution system. Hence. S03] . S00. complete prototype is tested. Here the designer finds solutions to problems by allowing his creativity aspects grow in a particular manner. Phase VI Planning for Consumption/use The purpose of this phase is to incorporate in the design all necessary user. Qualities of a creative designer [S96. The main tasks at this phase are • Preparation of process sheet. • Specify tools & machine requirements. But the success of engineering design depends on the modes of thinking and acting distinctively different from others. • Specify the condition of row materials. innovative design is an organized. Phase IV: Planning for manufacture This phase includes all the production planning and control activities necessary for the manufacture of the product.materials to be used and the manufacturing process to be adopted etc. • Design by creative design route • Engineering Design • Design by creative routs [Creative Design] This is a design method that demands maximum ‘creativity' from the part of the designer.oriented features. • Planning for production control. W95. Design is commonly thought of as a creative process involving the use of imagination and lateral thinking to create new and different products. are decided. where the designer simply modifies an existing system. There are two design methods for innovative design.e. • Examine service-terminated products to obtain useful information. • Planning QC systems. to generate and manipulate visual images in their heads. • Technique Creative designers have more than one approach to problem solving. In such a favourable environment creativity is further enhanced. The constructive non-conformists might generate a good idea. because they think they are right. • Non-conformist There are two types of non-conformists:-constructive and obstructive. • Motivation They always motivate others in the design team. a creative designer has the following qualities. till they reach a satisfactory solution. They are prepared to try alternative techniques. But the obstructive non-conformists will only slow down the design process. Edison tried hundreds of different light bulb designs before he found the carbon filament. etc. For example.The creative designer is generally a person of average intelligence. a visualiser. • Visualization ability. creative designers create new ideas out of bits of old designs they had seen in the past. they make minor modifications of what they already know –or. • Unwillingness to try new approaches • Fear of criticism • Lack of knowledge • Overconfidence due to past experience • Unwillingness to reject old solutions • Fear of authority • Difficulty in visualization • Inability to distinguish between cause and effect • Inability to collect complete information • Unwillingness to be different Page 5 Methods to enhance Creativity • Use of analogy • Asking question from different view points • Memories of past designs • Competitive products • Deliberate day-dreaming • Reading science fictions. • Knowledge All designers start their job with what they know. Creative designers have good ability to visualize. Obstructive non-conformists are those who take a stand just to have an opposing view. Intuition [S'01] . Constructive non-conformists are those who take a firm stand. Creative designers are ready to practice for a long enough period. Roadblocks to Creativity • Fear of making a mistake • Unwillingness to think and act in a way other than the accepted norm. • Willingness to practice Creativity comes with practice. • Ability to manipulate knowledge The ability to use the same knowledge in a different way is also an important quality of a designer. a hard worker and a constructive non-conformist with average knowledge about the problem at hand. During designing. they must have knowledge of past designs. • Desire to conform to standard solutions. Creative designers are constructive non-conformists. Hence. and they want to do things in their own way. Generally. • Risk taking A person who does not take the risk of making mistakes cannot become a good designer. elaborated in subconscious mind. The different steps in Engg. During preparation period. The final step is the verification. (ii) ENGINEERING DESIGN (W 96) Another procedure for obtaining innovative design is Engg. the designer analyses the need and collect all the necessary information required at various stages. Design. The next step is the incubation period. design process is given below: - Recognition of need Definition of the problem Gathering of Information . 9'00] Creative design route is the procedure through which a creative design is born. habitual or familiar methods must be avoided. Creative design route can be practiced by following the sequences shown in figure. Creative Design Route [W95. Intuitive ideas lead to a large number of good and even excellent solutions. this is a logical and intellectual attempt to solve design problems. Illumination is the sudden insight and throwing up with a solution. Concentration is the period when the designer digests all the aspects of the problem situation and tries various possible combinations. Now. 98. The success of this design lies with the creativity of the designer.Intuition means sudden ideas or flashes of inspiration and involves complex associations of ideas. testing and inspection of the design is done and the details are completed. It largely depends on discoveries and laws of science. 94. For a designer using creative methods for design. The designer relaxes away from the problem for some time. Apart from creativity-approach. The different ideas conceived are weighted and judged in the evaluation step. journals. The next step is collecting information . This is the most critical step in the design process. Thus. • Customs. Design Process Using Advanced Technology (W”00) . by eliminating unwanted ideas. Once the need has identified. or other agencies (See Art. The problem definition. This final design with every detail is furnished in last step-ie c ommunicating the design. finding several design ideas to meet the given need. Transformation & Convergence (S'97 5M) The entire design process can be said to have composed of three distinct phases Viz. In many phases of deign process a large quantity of information may be required. 6. • For both deigns. 3. That activity wherein the concept is converted into physical object is termed as transformation phase. the best design is emerged.Conceptualization Evaluation of concepts Communication of the design Since all design projects are meant for satisfying some need. Designs (W 94) • Intelligence is not a must for creative design-but the same is desirable in Engg. Inventiveness and creating is very important in this step. • In both design methods brainstorming and Synetics can be applied. The advantages and disadvantages of each idea against its performance. aims at generating as many ideas as possible to solve a given design problem. the development of a new technology or the desire to improve an existing product. • Testing and inspection is applicable for both designs. Transformation and Convergence phases. Need Analysis is the technique used to define the problem(Chapter 6). habits and traditions are enemies of creativity – but the same are required in engineering design. • Creative person is highly intuitive and independent in thinking and usually resists working in group – but engineering designers like teamwork. The required information can be obtained from textbooks. Page 6 Common features between Creative Design & Engg. the next step is to define the design problem .94) • The preparation phase in creative design and need analysis in Engg. The success of a design project depends on the clarity in the definition of the problem. illumination – but no such philosophy is followed in engineering designs. cost aesthetics etc is valued. any design work starts withRecognition of the need . the success depends on the clarity with which the need statement is prepared.4) The conceptualization step involves. Design is more or less common. where the best optimal solution is tried for. Divergence.9. The need for a design is initiated by either a market requirement. • Reviewing is applicable in both design methods. Both steps deal with analyzing the need. definitions of any special technical terms. Difference between Creative Designs & Engg. the constraints on the design and the criteria that will be used to evaluate the designs. 3. • Creative design is based on use of analogy and synthesis of alternatives – but engineering design is based on proven laws and past experience. these activities belong to the Divergence phase.10. The convergence is a narrowing process. need analysis and conceptualization etc. Design (W. After evaluation. Design. what the design is intended to accomplish. It should include objectives and goals. The definition of the problem expresses as specifically as possible. • Creative design involves phases like incubation. Divergence. Explain the basics procedure of design synthesis giving suitable examples. QUESTIONS • How can you explain the term design? Explain the process of mechanical design. • What are the common features and differences between creative design activities and Engg? Design activities. Write down the different statements about creativity and creative designers. 6M) • The creative design process can be considered to be ……… (S93) • Discuss creativity and creative design. 1 M) • What is morphology of design? Explain the various steps with the help of block diagram (W. The CAD allows the designer to conceptualize objects more easily. Slow process of design development (W'94) • With suitable examples. The design process in CAD system consists of the following stages. 8M) • The mechanical design process normally has six stages and amongst them the three stage are ---------. Ans. (S'01) . It has not been benefited greatly from advances in computer technology. What are the various qualities of creative designer? Give the brief description of these.95) • The three stages of design are………… (W 96) • State the different phases that are involved in morphology of design (S. Ans. (S. Use examples to explain. and convergence phases in the design of a new product. Current computer tools such as ‘computer-aided drafting' are restricted to the end of the design process and play no fundamental role in aiding design. (W'93) • The process of design by evolution adopted by craftsman is a …………. transformation. Engineers still use computers only in peripheral tasks.Although Engineering is a major sector of the economy in a developing country. Explain why some stages are repeated several times. W'98) • Good design requires both-----. compare ‘Design by evolution' and ‘Design by innovation'. or the physical description of the object. S94.93.5M) • What feedback loops provide information for the redesign of products and the productive systems.--------. Explain these in brief. Discuss the role of creativity in the designs process. (S'00).------. (S'97. (W'99) • What are the most important steps involved in the design process? Explain? (W'00) • What are the methods currently being adopted for design process using advanced technology? (W'00) • Name various phases in design morphology. (S'00) • Explain the process involved in creativity. Design process and explain (W'96) • Justify the statement with reasons ‘Modern design problems cannot be handled by traditional methods'. What are the stages of these routes.96) • Briefly discuss the concept of creativity as applicable for solving design problems (W 98.(S99. (S'97) • What are the three different stages in the design process? Explain with example. • Geometric modeling • Analysis and optimization • Evaluation • Documentation and drafting. (S94. such as drafting and analyzing. (S'93) • Define creative design routes. CAD systems have been sophisticated and 2D and 3D models are available. Computer-aided Design. (CAD) means a class of tools for crating drawing. Analysis and Synthesis. It aids only in the final drafting of the specifications.. (W'94) • Discuss the divergence. (S '02). Explain briefly with the help of examples. (S'01) • Compare the design synthesis and design analysis. (W 95) • What do you understand by intuition (S 01) • Draw a flow-chart showing different stages of engineering design. Explain these in brief. (S 96) • Enumerate the steps in Engg. but not in making fundamental design decisions. • What do you mean by creative design routes. 6M) • What makes the design process tortuous? Explain (W 99. (W '05. (W 05.e. A person buys a pen because he ‘needs' to write.esteem. -Changing the power of a motor.3. a need to develop a better product is identified. device or a system. Hierarchy of Human needs (W' 96) Maslow developed a hierarchy of human needs as given below 1. Physiological needs . Variation of an existing product. Safety and security needs For a person whose physiological needs are met. when the customers are unsatisfied with the present ‘model'. Similarly. Self-fulfillment needs These are the needs for the realisation of one's full potential through self-development. i. protection against danger. Psychological needs These are the needs for self-respect and self. When a turner hears an awkward noise from some part of the lathe he identifies/ recognises a need.4. Design problem. Identification/Recognition of Needs (W 96) The beginning of any design process is the recognition of need or problem. and self-expression. These include. Design (S'01) • What major steps are involved in design process? Briefly explain each one (W'01). the lathe requires repair. These examples show that needs are nothing but a scarcity or problem or wants felt by a person. and for recognition. (Use of analogy) (W '94). sleep etc. What is a need? A need can be defined as a personnel unfulfilled vacancy which determines and organizes all psychological and behavioral activities in the direction of fulfilling the vacancy A product can be product and marketed only if it is ‘needed' by the customer. 4. Social needs Once the physiological and safety needs are met.• Explain Engg.1. preliminary design and detailed design. (W'98) • ___ is one of the most powerful aids to creativity in design. 3. Needs can be identified from. Eg . Also explain the flow of work during the design process. hunger. . the next dominant need is social need. 8M) Page 7 CHAPTER 4 IDENTIFICATION OF NEED 4. (S 05) • Explain ‘Design processes. etc. (i). a new need is recognised. When the sales personnel observes that their customers are always complaining of poor performance of the products. • Discuss the stages in engineering design process with the help of example. 4. Illustrate the steps followed with the help of a figure.Changing the length of a cylinder. 5. (S'02) • Give the checklist for an engg. he want to be “in group”.For example.These are the basic needs of the body. A patient ‘needs' something that can cure his illness. • Careful market analysis • Statements made by politicians from their observations • Interpretations of a community's requirements • Trends in other parts of the world 4. creativity. sex. This could be a change in a single or a few parameters of an existing product. In fact a designer's goal is to find solutions to such problems 4. 8M) • What do you understand by ‘morphology of design'? Discuss the phases of feasibility study. • What do you understand by the term “creativity”? What are its requirements? ('03). the new emerging needs are safety needs. threat etc. which can generate ideas for the development of new products. Variety of Needs [S'00] Following are the needs. etc. thirst. • What do you understand by the design process? List out the various phases involved and explain them briefly. For example he/she want to love and be loved. 2.2. only if. the next step is to prepare the need statement. 2. the company recognizes a need to re-design it. [W'96] 2. needs [S'97] 5. With the free-entry of Chinese products to Indian market. manipulate it according to a set of instructions and provide the desired output on CRT and printer” Questions 1. This implies the need to redesign some of the features of an existing product.and be as light as possible. Ans. a company has to identify or locate a need before the production of any device. there is more tendency to buy off-the shelf components for short-run products.• Improvements in the existing product. accepting the input power at varying voltage between the limits__and__volts “. . Voltage stabilizer “A solid state noiseless electrical device of adequate power rating to provide continuously an output at constant voltage. a corresponding change in product design may be demanded. In other words-It is the objective of design. When a company observes that their products do not perform well. expressed in the form of a statement. Examples: 1. This crucial step is called Recognition/ Identification of need. Give one need statement for each of the following Bicycle (ii) Voltage stabilizer (iii) Personnel Computer [S'93] 3. [S'00] Page 8 CHAPTER 5 PRODUCT PLANNING 5. 4. be easy to maintain etc “ (ii).the market conditions are favorable in respect of competition. Whatever may be the situation. (iii) A change in production model Whenever the production model changes from job-shop to mass.5 Need Statement Once the need has recognized. Such needs can arise. have adequate life. it will go for product design. . iii). Explain the steps involved in identification of a problem by a designer [S'96] 4. Bicycle: The need statement for a bicycle could be “A device for a common person to travel reasonable distance comfortably with least effort” –“The initial cost should be low. Every product is made in response to………. when -Customers want a new feature or better performance than existing features -A vendor can no longer supply components or materials that had been used so far -Manufacturing or assembly departments identifies a quality improvement -Invention of a new technology that can be incorporated in the existing design.the purposed product will guarantee a handsome profit . For example. Personnel Computer “A computing device to accept input data.of individual or society. Enumerate and explain variety of needs which can generate ideas for the Development of new product. List hierarchy of human needs that motivate individuals. The indications for input and output voltage levels may be provided. Need Statement – Examples [S ‘93] Give one need statement for each of the following Bicycle Voltage stabilizers Personnel Computer i).1 Introduction Once the top management of an organisation recognized a need to develop a product. manufacturers in India recognize a need to sell their products at a lower price. It is a general statement specifying the problem for which a solution is required. money and people. More over it will result in optimum and efficient use of resources. purchasing agents. For example Boeing 747 aircraft (which has over 50. 5. It must contain the time-as well as resource allocation for each of the products. He is responsible for success of the product in the market. and hence revenue from products P 1 . Owing to the design and manufacture of the new product. 7.3 . These show that. machineries). 5.000 components) required over 10 thousand persons' years of design time. After the product plan in made. He is a link between the product and the customer.Product Planning [S 01] Planning is the process used to develop a scheme for scheduling and committing the resources of time. He always sees “whether the customer like this product? 3. P 2 . 2. Planning means allocation of resources such as money. say P 1 . drafters. the management begins a project for a new product design. he must clearly understand needs for the product as well as its engineering requirements. .the purposed design is worthwhile. people and equipments etc.4. 6. the company has to decide a time-schedule for the design and manufacture of the new product. Marketing Manager. Detailer In many companies the design engineer is responsible for specification development. co-coordinated and monitored. He must be an engineering graduate having vast experience in the particular product area. Their titles may vary from company to company. technicians. For example assume that a company already manufacturing 3 products. or the design demands huge investments beyond the capacity of the organisation. A plan shows how a project will be initiated.. Materials Specialist. 1.identification. to be forwarded or not. conceptual design and the early stages of product design. Such plan made by the management is called the product plan. A product plan is a decision-making as regards to the design and manufacture of a product. Feasibility study is a preliminary analysis for making a decision regarding the design project. If the feasibility study reveals that the proposed design project does not bring comfortable revenue. The first step in planning is to form a design team. performing experiments etc. by considering the revenues from different products. the company has to ensure the worth of the project. For that. Design Engineer. Hence. and quality control specialists. P 2 and P 3 identifies a need to design a new product ‘N'. material scientists. planning. The first phase in any design process is identification of needs. people etc.2 Feasibility Study. Members of Design Team Following is a list of individuals needed in a design team. A design team may include thousands of design and manufacturing engineers. Organisation Of Design Group The complexity of mechanical devices has grown rapidly over the last 200 years. Drafter A drafter aids the design engineer and detailer by making drawing of the product. Thousands of designers worked over a three-year period on the project. In many companies the detailer and the drafter are the same individual. develops manufacturing and assembly documents. the project is dropped. the production volume. he must posses both creative and analytical skills. Manufacturing Engineer. The technicians aid the design engineer in developing test-apparatus.the necessary resources are available . 5. Once the need has been identified. Since any design activity consumes company resources like money. This person is responsible for suggesting ideas for the proposed product. 5.and P 3 may be affected (due to re-allocation of company resources such as raw materials. The starting point of a design project is a need. organized. design work is generally done by a team or group. the desire to improve an existing product or even by the development of a technology.5. Technician. all working over many years. He can give advice on the various manufacturing processes available in the industry. Needs may be identified by market survey. In this situation. 5. 4. The project is then turned over to detailers who finishes the details. –the planning of these resources is the next phase after need. He knows the best manufacturing process suitable for the production of the particular product. Step 1 Identify the tasks In the first step of the planning of the design project. In that case. Functional Organisation (13%) Each project is assigned to a relevant functional area or group within a functional area. Collect and evaluate customer requirements and competition scenario. Suppliers' Representative. Project Team (16%) A project manager is put in charge of a project team composed of a core group of personnels from several functional areas or groups assigned on a full time basis. Balanced Matrix (16%) Here the project manager and functional manager work together. They generally have background in fine arts and in human factor analysis. This inspection is done on finished products as well as raw materials purchased from vendors. 2. resources required. In some other cases. Quality Control Specialist. Project matrix. time. 4. Test prototype No1 and select one design for finalisation. Page 9 5. 8. Establish two concepts for product development. . a. Note that assembly process is an important aspect of product design. and the responsibility and authority for completing the project rests with functional managers. the representative of the supplier of the specified component must be included in the design team. There are five steps to establish a plan. A project manager is assigned to oversee the project. Industrial Engineer. Given below is a list of tasks drafted by a design team. they can be organised into different structures. d. 10. A project plan is used to keep the project under control. a certain material is to be chosen according to some features of the product. the company may purchase components or sub-assemblies from outsources. Industrial designers are responsible for how a product looks and how well it interacts with customers. A functional area focuses on a single discipline.7. Functional matrix (26%) It is another organisational structure obtained by combining functional as well as matrix organisations. Assembly Manager. The number in the bracket shows the percentage of design projects that use that particular organisation structure. Develop final prototype. 9. (28%) It is an organisation structure having the features of project and matrix organisations. Material specialist can give advice on properties of different materials. the different tasks needed to bring the problem from its initial state to the final products are identified. b.In some products. 5. Listed below are the five organisational structures. • Develop a sequence for these tasks. As part of product development. for the development of a certain product. It helps the design team and management to know how the project is actually progressing. • Identify the task • State the objective of each task • Estimate Personnel's. They are.6 Organisational Structure of Design Teams Since a design project requires individuals with different fields of expertise. 11. The tasks are the activities to be performed during the design process. The assembly manager is responsible for putting the product together. Task Clarification [S 01] A project plan is a document that defines the tasks necessary to be completed during a design process. the choice of the material is based on availability. A quality control specialist observes how well the product meets specifications. 1. 3. c. 5. • Estimate product development cost. g. Step . two months Concept generation Two designers. (a) above. two week. they need to be refined to ensure that the results of the activities are the stated objectives. Redesign and produce proto type No2.e. [S '01] . CPM is the best method to accomplish this. time etc. Market research is necessary before starting the production of any product. Step 3: Estimate the Personnel. j. Prepare patent applications. Develop marketing plan. f. State the objective for each task. For example. (True) [S '97] 2. for the task No. Step 5 Estimate Product Development Cost On the basis of the above steps. Even though the tasks are initially identified.2. The above plan developed in the early stage of the design has to be refined as the project progresses. Completion of each of the tasks listed above will consume resources such as personnel. h. the costs for developing the product can be estimated. Develop quality control procedures. before its result is needed. An estimate of the requirement of resources may look like: Task Personnel/time Collecting data Two market surveyors. Time & other Resources Required. Questions 1. Step 4 Develop a Sequence for the tasks The next step is scheduling of tasks-the purpose is to ensure that each task is completed. k. Write a short note on – Product planning and task classification. the objective is to collect information required for developing specification. Complete production documentation. Develop packaging. Normally design cost is only about 5% of manufacturing cost. l. i. Establish product appearance. Field test prototype No2.