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Back to the future with CAD: its impact on product design and development
Back to the future with CAD: its impact on product design and development I. Black Department of Mechanical Engineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, UK
This paper briefly examines the history of the management and organisation of the product development cycle. It looks at some of the key factors that have affected product development, and how information technology through CAD may have opened the door to a simultaneous product design process that has more in common with 'older' craft-based methods than those developed in the recent industrial era. Keywords: computer-aided design, engineering design, design methodology, design management
PRODUCT DESIGN, THE AGE OF THE ARTISAN A N D THE INDUSTRIAL REVOLUTION The pre-industrial culture saw the development of many artefacts that were apparently created and crafted without any conscious design effort. Produced by artisans, these objects were highly functional, complex, and even attractive (e.g. musical instruments, the cartwheel, arms and armour, etc.). Cross I notes that their apparent simpficity 'often masks the complexity of the relationship between form and function'. Jones~ further suggests that this complexity has been achieved through evolution over a long time scale with very gradual adjustments. He argues that these products have evolved like plants and animals and so have an organic look. Whatever the aesthetics of those kinds of product there can be no doubt that they were made by individuals with complete control over the whole development cycle from assessing market need, to inception, to design, to manufacture and also to sales. The product design not
Vol 11 No 4 October 1990
only evolved over time but also changed during the development cycle itself: thus the development of the product was highly dependent upon the way the artisan made it. In effect, the artisan had mastered all the product development skills - he was an innovator, a market researcher, an industrial designer, a design engineer as well as a production engineer and a sales executive. With the advent of the industrial revolution the skills of the artisan became focused into more specialized tasks which formed only part of the overall product development cycle. Along with growing industrialization and the centralization of production facilities came the separation of design from a product's manufacture, its marketing and its eventual use. Drawings and documentation produced in isolation by design personnel working independently of others are fairly limited as a communications medium. Such isolation does not guarantee success and, indeed, is less likely to result in new or innovative designs. Freeman 3 reminds us that successful industrial innovation is a twin
0142-694X/90/04207-05 © 1990Butterworth-HeinemannLtd
207
process involving the recognition of a potential market allied with the knowledge of new scientific processes or discoveries: 'necessity may be the mother of invention but procreation still requires a partner'. However, despite the increasing divide between design and other product development activities throughout the industrial era, highly innovative products were still generated by 'gifted' individuals, as exemplified by Marconi, Brunel, Baekeland and others. These luminaries were gifted with not only all the artisan skills mentioned above but, importandy, they did not limit themselves to only one task in the product development cycle. Their own success and that of their products bears testimony to this approach.
MODERN PRODUCT DESIGN The post Seond World War period has seen still further isolation of the design process in product manufacturing, Often design has been regarM~d as an intellectual pursuit somewhat separate from the whole 'nasty' business of manufacturing, marketing and sales. Unfortunately such an attitude is still prevalent in the UK with design 'kudos' often being the ultimate objective amongst design engineers rather than such (important) notions as fitness for purpose, availability on time and meeting cost targets 4. In the past, influential product factors were quantity and variety. These factors still play a part in product planning, but most importantly the determining factor is design s . Shortcomings in the product design process are clearly being identified in the market place through lack of sales6. In reality the problem lies not with product design per se but with the lack of communication and understanding between design engineers and other functions such as marketing and manufacturing. By failing to understand the technology and methods of production, design engineers may aggravate manufacturing problems and produce unsympathetic designs; by ignoring marketing, product designs can be produced that will either not sell or fail expectations in the market place. As a result, the design (and manufacture) process goes through many iterations with eventually the product coming on the market at a higher price and much later than its other international competitors. Basically design engineers have failed in the past to take account of the totality of the product development cycle when arriving at their designs. This is not primarily the fault of design engineers, but can be attributable to both the organisation and structure of the product development process, through a lack of integration. The obvious solution to the problem is to give back to the design engineer a greater awareness of the product development cycle, hence increasing the availability and 'quality' of information emanating from the design function. The author contends that this condition can be significandy assisted through both changing the procedure and practise of product design, and by utilizing CAD technology in the product development process.
208
THE PROCESS OF PRODUCT DESIGN Today's engineered products are becoming ever more complex and specialized in their configuration and application. In addition, to satisfy the demands of world markets will increasingly dictate and expose the effectiveness of current product design practice. It would be expecting too much nowadays of one individual to be fully responsible for and conversant with the identification of all relevant market needs right through to selling the final manufactured design, and beyond. This situation ideally calls for multi-disciplinary participation in product development, with teams of functionally specialized individuals working in a design process which allows an integrated approach. Burlington 4 has identified three key product design issues that are principally determined by the market place, i.e. • Fitness for purpose; or rum-price performance (relating rn flm~rlanal a~rh~tir 211(~ t~th~- ~ot-tn.~ ]t]t~tt ........... :.- ........................ : ....... from competltave pressures between suppliers to that market. • Availability on time; where market forces, generated largely by the competitive scenario, continue to reduce product life spans, so that pressure on development timescales increases. • Meeting cost targets; which incresingly dominates and disciplines the overall product design function. Price competitiveness can be a key market force. .....
With the above goals in mind, some companies are moving towards what has been termed a simultaneous approach to their engineering activities 7,s. This requires a re-structuring of the design process, replacing the conventional pure sequential structures that are traditionally employed (represented in Figure 1) with concurrent forms. With the simultaneous approach, there are three specific underlying principles9: • to perform individual activities as fast but as rigorously as practicable; • to perform activities in parallel, rather than sequentially; • to reduce the number of interfaces required in the design process to a minimum. Simultaneous design involves, as far as possible, complete reappraisal of existing information flows within the total design and manufacturing processes. Traditional barriers must open up, and ideas have to be shared through communication and teamwork. Sharing, rather than retarding, information is the key to a successful simultaneous operation. However, as previously mentioned, paralleling activities can only be achieved by a radical re-design of the design process itselL This is never easy in conventional manufacturing industries where cultural traditions are predominant and extremely difficult to change. A concurrent design and manufacturing process presents testing problems for the organization, management and control of people, the activities they work on, and, most
DESIGN STUDIES
Clarification of task; objectives; ~etting etm~ng proDrem \ ~, MNA~RERg X ~ PERCEIVED
f
~ ~
/
~
Setting and evaluating funct on structures; generating solution concepts; laying-out of systems
..... / ~ reeaDacKtoop / \ / .j_
/
Detail design of components and sub-systems; preparation of manufacturing docu~atiort; rinG, checks
/
Procedural boundary
Figure I. A sequential model of the engineering design process importantly, the information they need to work with. Nevertheless, there are real benefits to be gained from such an integrated approach, e.g. reduced incidence of design changes, lower production costs and better overall non-price performance m-lz. It has been further contended that concurrency can be most effectively addressed through a more systematic structuring of the design process, since this will allow a rigorous product development schedule, and facilitate integrated multidisciplinary participation 13.
THE IMPACT A N D ROLE OF CAD TECHNOLOGY The competitive dynamic market place has led to shorter product lifetimes with consequent pressure for increased design productivity. This 'crisis' can be partly resolved by utilizing mdern CAD techniques to both assist with the enhancement of non-price factors and by adding value to a product. Product design, non-price factors and added value are inextricably linked - any improvement in the latter will yield associated improvements in the former 14. If CAD is defined as the use of computer-based information systems to assist in the creation, modification, analysis and optimization of a design, it will therefore affect, to varying extent, all the different design and manufacturing activities in the product development cycle. The potential benefits of CAD in this process are enormous. CAD technology essentially allows the simulation, both mathematically and graphically, of the behaviour and form of various product systems, subsystems and components. The CAD process itself will not lead directly to new product concepts or innovatory
Vol 11 No 4 October 1990
designs is - CAD merely acts as a tool which the design engineer may utilize in the task of product design. There will always will be the need for intuitive flair and creative insight on the part of the design engineer. In theory it is possible to directly transfer the output from the CAD process to the manufacturing (or CAM) process electronically thus significantly reducing the dependence on working from hard-copy drawings and so limit any opportunity for re- or mis-interpretation of design information. The design engineer using CAD techniques has the potential to define and refine various functionality and manufacturability attributes of the proposed design configuration (such as limits and fits, tolerance values, process selection, etc.) at an early stage in the design process. The direct re-use of design information is undoubtedly a major benefit of deploying CAD technology, and has been shown to lead to a reduction in product manufacturing timescales 16. Obviously, to make the direct re-use of design data an effective proposition necessitates both compatibility between the design and manufacturing processes and cooperation between design and manufacturing personnel, assisted by supportive techniques like design for assembly/manufacture and design to cost 17. The adoption of CAD will both require and impose significant change within a firm. Oakley is states that the increased adoption of CAD will 'encourage a closer working relationship between design, manufacturing and other activities': it allows both design engineers and manufacturing engineers to have access to the same information concurrently instead of consecutively and thus enables the design and manufacturing functions to work together 9'13 - in other words it will lead to the simultaneous design and development of both the product and the process. Simultaneous product (and process)
209
As before (goal setting)
MARKET ~ . . NEED . oR
PERCEIVED REQUIREMENT
/> . _
~
eetT~octjbo
Feedback loop
-
.---- Iterotive cycles Preparation of manufacturing documentation; final check
Setting and evaluating function structures; looking at concept vorMnts; creating solution concepts (totnl conceptual design)
DELIVERY
Firming up of solution concepts layout development and refinement assessing functionality, cost, manufac(urability and stondardisction implications detail design of ports and sub-systems (total system design)
Figure 2. Systematic concurrent engineering lrroduct design and manufacturing with CAD design utilizing CAD methods can also be argued to be dependent on a systematic structuring of the complete design and manufacturing process 13'19. Figure 2 attempts to show a representative model of a concurrent design and manufacturing structure utilizing CAD techniques. There are, however, many problems with the deployment and utiliTation of CAD. First, with the particular needs of individual design activities each organization must, to a certain extent, customize the available applications software to its own purposes, e.g. for particular mechanical sizing problems, for the quick production of drawing frame graphics, or for linking with a database management system. Second, companies are unlikely to share the productivity gains from CAD cheaply and so there is a high entry cost for firms new to the technology. These costs demand that managers must carefully weigh the benefits of CAD against the drawbacks within their own particular business sector and/or manufacturing scenario. Finally, the technology of CAD changes so rapidly that long-term, strategic planning must be carefully done before committment to any capital expenditure is possible. All of these will pose difficulties as most managers usually either lack the experience to evaluate, or are uncertain about the potential benefits of CAD, or both 2°-22. Coupled with any inability to manage design with genuine teamwork and cooperation will aggravate the situation. The problems to be faced (and solved) will no doubt become more challenging as it becomes plain that CAD must be incorporated into a well-organized programme of simultaneous/systematic product development, together with the requisite organizational changes, for it to produce real productivity gains.
210
The current compartmentalized departmental structure prevalent in many UK manufacturing companies does not lend itself readily to the integration of product development functions that CAD can facilitate, particularly when dealing with today's complex and specialized products. 'Discipline-centred' project teams have been recommended as one suitable option for improving this situation 23'24. Working within a hybrid org~niT-atiolml structure, a group of variously disciplined engineers are responsible for all aspects of a product from specification through design to manufacture. Each engineer would have inputs dependent on Ms/her backgrmmd skills and could make contributions at each stage of product development. Again, the key word is imegra~m, and by combining activities there wig be an increased awareness of the need to make appropriate inputs at the correct time. However, it is interesting to note that, in sharp contrast, Stark 19 has suggested that there should be no set dogma of organizational form, as long as the firm can succeed in its corporate objectives for product design with CAD. The important point to note is that all of the above essentially reflect what was done on an i n d i ~ u a l basis by the ar~san. For the ideals of multi-disciplinary, concurrent CAD to be achieved, a complete re-assessment of the training and education of managers, design engineers and manufacturing engineers is needed. Design engineers must know and be aware of the manufacturing processes and technologies available. Managers and production personnel must have an element of design in their backgrounds. The pressing requirement is for an education and training philosophy that gives design engineers a working knowledge of manufacturing and manufacturing engineers a deeper understanding of the problems and
DESIGN STUDIES
techniques of design. The critical importance of marketing should also be strongly emphasized throughout such 'programmes.
CONCLUSIONS The limitations of many current product design and development practices have proved a serious problem to the competitiveness of U K manufacturing industry. In order to be competitive, today's design engineers have to consider the overall scenario for a product (such as its use and function, the intended market place, its manufacture, etc.) just as the artisans of craft-based pre-industrial culture did. However, it must be recognized that modern product development is now beyond the capabilities of any one person. Ideally, the most effective response to this situation is for a forum of committed contributing experts that have mastered all the activities of the product development cycle, working in a concurrent design/manufacturing structure, who can guide a product from its inception through design and manufacture and thence into sales. Such an approach very closely models that of artisans except that instead of one individual crafting a product it is a team of carefully managed personnel who are all aware of each other's roles and tasks. Integration and communication within a firm, and with its customers, is both critical to the success or failure of a product. Such integration has, in the past, been singularly absent from the majority of UK firms but it has been contended in this paper that CAD is a means by which this integration can be facilitated. CAD offers a catalyst in which the design and manufacture functions can be integrated and so provide some certainty that what is designed can actually be made. It also provides an ideal working means for the simultaneous approach to product (and process) design. It must be borne in mind at all times that CAD by itself is only a tool - there has to be a conscious and explicit methodology which matches the existing company resources of people and technology to achievable products and market needs. REFERENCES Cross, N 'The changing design process', in Roy, R. and
Wield, D. (Eds.) Product design and technological innovat/on, Open University Press (1986) 2 Jones, J C Design methods, John Wiley and Sons, Chichester, UK (1980) Freeman, C 'Successful industrial innovation', in Roy, R.
and Wield, D. (Eds.) Product design and technological innovation, Open University Press (1986) 4 Burlington, M 'Strategy for design'. Proceedings of engineering design "86 congress, Birmingham, seminar 3A, 1986 5 Beitz, W 'Strategies for planning and developing innova-
Vol 11 No 4 October 1990
five market orientated products'. Proc sixth internatational conference on engineering design, Vol 1 (1989)pp 211-227 6 Gardiner, P and Rothwell, R Innovation, The Design Council, 1985 Liley, J E N 'The management of design'. Proc of sixth international conference on engineering design, Vol 1 (1989) pp 245-262 Putnam, A O 'A redesign for engineering'. Harvard
business review, 1985, pp 139-144 Wilson, P M and Greaves, J 'Forward engineering - a
strategic link between design and profit'. Proceedings of mechatronics conference (1989) 10 Ford, J C 'Simultaneous engineering (design to manufacture)'. Proceedingsof international bus, truck and car product and manufacturing technology exhibition and congress (1989) 11 Corbett, J 'Reduction of engineering timescales/ simultaneous engineering'. Proc. international bus, truck, and car product and manufacturing technol, exhibition and congress (1989) 12 King, J A 'Simultaneous engineering - how to make it work'. Proc. international bus, truck and car product and manufacturing technology exhibition and congress (1989) 13 Black, I 'Embodiment design: facilitating a simultaneous
approach to mechanical CAD'. Computer-aided eng J, Vol 7, No 2 (April 1990) pp 49-53 14 Rothwell, R, Gardiner, P and Schott, K Design and the
economy, The Design Council, London, UK (1983) 15 Pugh, S and Hollins, W Successful product design, Butterworths, Borough Green, UK (1990) 16 Black I and Murray, J L 'Concept embodiment - a
methodological basis for effective computer-aided design'. Proc of sixth international conference on engineering design Vol 2, (1989) pp 929-946 17 Corbett, J 'Design for economic manufacture'. Proc first conf. on the education and training of engineering designers (1983) pp 27-33 18 Oaldey, M Managing product design, Wiedenfield and
Nicholson, London, UK (1984) 19 Cross, N Engineering design methods, John Wiley and Sons,
Chichester, UK (1989) 20 Stark, J Managing CAD~CAM, McGraw-Hill, London, UK (1988) 21 Medland, A and BurneR, P CAD~CAM in practice: a manager's guide to understanding and using CAD~CAM, Kogan Page, London, UK (1986) 22 Stark, J What every engineer should know about practical CAD~CAM applications, Marcel Dekker (1986) 23 National Economic Development Council - design working party. A fiamework for communicating the full role of design in product development and innovation (1985) 24 Cross, J D and Black, I 'Putting the design into mechanical CAD: a company methodology', Design Studies, Vol 9, No 4 (October 1988) pp 214-218
211
This paper briefly examines the history of the management and organisation of the product development cycle. It looks at some of the key factors that have affected product development, and how information technology through CAD may have opened the door to a simultaneous product design process that has more in common with 'older' craft-based methods than those developed in the recent industrial era. Keywords: computer-aided design, engineering design, design methodology, design management
PRODUCT DESIGN, THE AGE OF THE ARTISAN A N D THE INDUSTRIAL REVOLUTION The pre-industrial culture saw the development of many artefacts that were apparently created and crafted without any conscious design effort. Produced by artisans, these objects were highly functional, complex, and even attractive (e.g. musical instruments, the cartwheel, arms and armour, etc.). Cross I notes that their apparent simpficity 'often masks the complexity of the relationship between form and function'. Jones~ further suggests that this complexity has been achieved through evolution over a long time scale with very gradual adjustments. He argues that these products have evolved like plants and animals and so have an organic look. Whatever the aesthetics of those kinds of product there can be no doubt that they were made by individuals with complete control over the whole development cycle from assessing market need, to inception, to design, to manufacture and also to sales. The product design not
Vol 11 No 4 October 1990
only evolved over time but also changed during the development cycle itself: thus the development of the product was highly dependent upon the way the artisan made it. In effect, the artisan had mastered all the product development skills - he was an innovator, a market researcher, an industrial designer, a design engineer as well as a production engineer and a sales executive. With the advent of the industrial revolution the skills of the artisan became focused into more specialized tasks which formed only part of the overall product development cycle. Along with growing industrialization and the centralization of production facilities came the separation of design from a product's manufacture, its marketing and its eventual use. Drawings and documentation produced in isolation by design personnel working independently of others are fairly limited as a communications medium. Such isolation does not guarantee success and, indeed, is less likely to result in new or innovative designs. Freeman 3 reminds us that successful industrial innovation is a twin
0142-694X/90/04207-05 © 1990Butterworth-HeinemannLtd
207
process involving the recognition of a potential market allied with the knowledge of new scientific processes or discoveries: 'necessity may be the mother of invention but procreation still requires a partner'. However, despite the increasing divide between design and other product development activities throughout the industrial era, highly innovative products were still generated by 'gifted' individuals, as exemplified by Marconi, Brunel, Baekeland and others. These luminaries were gifted with not only all the artisan skills mentioned above but, importandy, they did not limit themselves to only one task in the product development cycle. Their own success and that of their products bears testimony to this approach.
MODERN PRODUCT DESIGN The post Seond World War period has seen still further isolation of the design process in product manufacturing, Often design has been regarM~d as an intellectual pursuit somewhat separate from the whole 'nasty' business of manufacturing, marketing and sales. Unfortunately such an attitude is still prevalent in the UK with design 'kudos' often being the ultimate objective amongst design engineers rather than such (important) notions as fitness for purpose, availability on time and meeting cost targets 4. In the past, influential product factors were quantity and variety. These factors still play a part in product planning, but most importantly the determining factor is design s . Shortcomings in the product design process are clearly being identified in the market place through lack of sales6. In reality the problem lies not with product design per se but with the lack of communication and understanding between design engineers and other functions such as marketing and manufacturing. By failing to understand the technology and methods of production, design engineers may aggravate manufacturing problems and produce unsympathetic designs; by ignoring marketing, product designs can be produced that will either not sell or fail expectations in the market place. As a result, the design (and manufacture) process goes through many iterations with eventually the product coming on the market at a higher price and much later than its other international competitors. Basically design engineers have failed in the past to take account of the totality of the product development cycle when arriving at their designs. This is not primarily the fault of design engineers, but can be attributable to both the organisation and structure of the product development process, through a lack of integration. The obvious solution to the problem is to give back to the design engineer a greater awareness of the product development cycle, hence increasing the availability and 'quality' of information emanating from the design function. The author contends that this condition can be significandy assisted through both changing the procedure and practise of product design, and by utilizing CAD technology in the product development process.
208
THE PROCESS OF PRODUCT DESIGN Today's engineered products are becoming ever more complex and specialized in their configuration and application. In addition, to satisfy the demands of world markets will increasingly dictate and expose the effectiveness of current product design practice. It would be expecting too much nowadays of one individual to be fully responsible for and conversant with the identification of all relevant market needs right through to selling the final manufactured design, and beyond. This situation ideally calls for multi-disciplinary participation in product development, with teams of functionally specialized individuals working in a design process which allows an integrated approach. Burlington 4 has identified three key product design issues that are principally determined by the market place, i.e. • Fitness for purpose; or rum-price performance (relating rn flm~rlanal a~rh~tir 211(~ t~th~- ~ot-tn.~ ]t]t~tt ........... :.- ........................ : ....... from competltave pressures between suppliers to that market. • Availability on time; where market forces, generated largely by the competitive scenario, continue to reduce product life spans, so that pressure on development timescales increases. • Meeting cost targets; which incresingly dominates and disciplines the overall product design function. Price competitiveness can be a key market force. .....
With the above goals in mind, some companies are moving towards what has been termed a simultaneous approach to their engineering activities 7,s. This requires a re-structuring of the design process, replacing the conventional pure sequential structures that are traditionally employed (represented in Figure 1) with concurrent forms. With the simultaneous approach, there are three specific underlying principles9: • to perform individual activities as fast but as rigorously as practicable; • to perform activities in parallel, rather than sequentially; • to reduce the number of interfaces required in the design process to a minimum. Simultaneous design involves, as far as possible, complete reappraisal of existing information flows within the total design and manufacturing processes. Traditional barriers must open up, and ideas have to be shared through communication and teamwork. Sharing, rather than retarding, information is the key to a successful simultaneous operation. However, as previously mentioned, paralleling activities can only be achieved by a radical re-design of the design process itselL This is never easy in conventional manufacturing industries where cultural traditions are predominant and extremely difficult to change. A concurrent design and manufacturing process presents testing problems for the organization, management and control of people, the activities they work on, and, most
DESIGN STUDIES
Clarification of task; objectives; ~etting etm~ng proDrem \ ~, MNA~RERg X ~ PERCEIVED
f
~ ~
/
~
Setting and evaluating funct on structures; generating solution concepts; laying-out of systems
..... / ~ reeaDacKtoop / \ / .j_
/
Detail design of components and sub-systems; preparation of manufacturing docu~atiort; rinG, checks
/
Procedural boundary
Figure I. A sequential model of the engineering design process importantly, the information they need to work with. Nevertheless, there are real benefits to be gained from such an integrated approach, e.g. reduced incidence of design changes, lower production costs and better overall non-price performance m-lz. It has been further contended that concurrency can be most effectively addressed through a more systematic structuring of the design process, since this will allow a rigorous product development schedule, and facilitate integrated multidisciplinary participation 13.
THE IMPACT A N D ROLE OF CAD TECHNOLOGY The competitive dynamic market place has led to shorter product lifetimes with consequent pressure for increased design productivity. This 'crisis' can be partly resolved by utilizing mdern CAD techniques to both assist with the enhancement of non-price factors and by adding value to a product. Product design, non-price factors and added value are inextricably linked - any improvement in the latter will yield associated improvements in the former 14. If CAD is defined as the use of computer-based information systems to assist in the creation, modification, analysis and optimization of a design, it will therefore affect, to varying extent, all the different design and manufacturing activities in the product development cycle. The potential benefits of CAD in this process are enormous. CAD technology essentially allows the simulation, both mathematically and graphically, of the behaviour and form of various product systems, subsystems and components. The CAD process itself will not lead directly to new product concepts or innovatory
Vol 11 No 4 October 1990
designs is - CAD merely acts as a tool which the design engineer may utilize in the task of product design. There will always will be the need for intuitive flair and creative insight on the part of the design engineer. In theory it is possible to directly transfer the output from the CAD process to the manufacturing (or CAM) process electronically thus significantly reducing the dependence on working from hard-copy drawings and so limit any opportunity for re- or mis-interpretation of design information. The design engineer using CAD techniques has the potential to define and refine various functionality and manufacturability attributes of the proposed design configuration (such as limits and fits, tolerance values, process selection, etc.) at an early stage in the design process. The direct re-use of design information is undoubtedly a major benefit of deploying CAD technology, and has been shown to lead to a reduction in product manufacturing timescales 16. Obviously, to make the direct re-use of design data an effective proposition necessitates both compatibility between the design and manufacturing processes and cooperation between design and manufacturing personnel, assisted by supportive techniques like design for assembly/manufacture and design to cost 17. The adoption of CAD will both require and impose significant change within a firm. Oakley is states that the increased adoption of CAD will 'encourage a closer working relationship between design, manufacturing and other activities': it allows both design engineers and manufacturing engineers to have access to the same information concurrently instead of consecutively and thus enables the design and manufacturing functions to work together 9'13 - in other words it will lead to the simultaneous design and development of both the product and the process. Simultaneous product (and process)
209
As before (goal setting)
MARKET ~ . . NEED . oR
PERCEIVED REQUIREMENT
/> . _
~
eetT~octjbo
Feedback loop
-
.---- Iterotive cycles Preparation of manufacturing documentation; final check
Setting and evaluating function structures; looking at concept vorMnts; creating solution concepts (totnl conceptual design)
DELIVERY
Firming up of solution concepts layout development and refinement assessing functionality, cost, manufac(urability and stondardisction implications detail design of ports and sub-systems (total system design)
Figure 2. Systematic concurrent engineering lrroduct design and manufacturing with CAD design utilizing CAD methods can also be argued to be dependent on a systematic structuring of the complete design and manufacturing process 13'19. Figure 2 attempts to show a representative model of a concurrent design and manufacturing structure utilizing CAD techniques. There are, however, many problems with the deployment and utiliTation of CAD. First, with the particular needs of individual design activities each organization must, to a certain extent, customize the available applications software to its own purposes, e.g. for particular mechanical sizing problems, for the quick production of drawing frame graphics, or for linking with a database management system. Second, companies are unlikely to share the productivity gains from CAD cheaply and so there is a high entry cost for firms new to the technology. These costs demand that managers must carefully weigh the benefits of CAD against the drawbacks within their own particular business sector and/or manufacturing scenario. Finally, the technology of CAD changes so rapidly that long-term, strategic planning must be carefully done before committment to any capital expenditure is possible. All of these will pose difficulties as most managers usually either lack the experience to evaluate, or are uncertain about the potential benefits of CAD, or both 2°-22. Coupled with any inability to manage design with genuine teamwork and cooperation will aggravate the situation. The problems to be faced (and solved) will no doubt become more challenging as it becomes plain that CAD must be incorporated into a well-organized programme of simultaneous/systematic product development, together with the requisite organizational changes, for it to produce real productivity gains.
210
The current compartmentalized departmental structure prevalent in many UK manufacturing companies does not lend itself readily to the integration of product development functions that CAD can facilitate, particularly when dealing with today's complex and specialized products. 'Discipline-centred' project teams have been recommended as one suitable option for improving this situation 23'24. Working within a hybrid org~niT-atiolml structure, a group of variously disciplined engineers are responsible for all aspects of a product from specification through design to manufacture. Each engineer would have inputs dependent on Ms/her backgrmmd skills and could make contributions at each stage of product development. Again, the key word is imegra~m, and by combining activities there wig be an increased awareness of the need to make appropriate inputs at the correct time. However, it is interesting to note that, in sharp contrast, Stark 19 has suggested that there should be no set dogma of organizational form, as long as the firm can succeed in its corporate objectives for product design with CAD. The important point to note is that all of the above essentially reflect what was done on an i n d i ~ u a l basis by the ar~san. For the ideals of multi-disciplinary, concurrent CAD to be achieved, a complete re-assessment of the training and education of managers, design engineers and manufacturing engineers is needed. Design engineers must know and be aware of the manufacturing processes and technologies available. Managers and production personnel must have an element of design in their backgrounds. The pressing requirement is for an education and training philosophy that gives design engineers a working knowledge of manufacturing and manufacturing engineers a deeper understanding of the problems and
DESIGN STUDIES
techniques of design. The critical importance of marketing should also be strongly emphasized throughout such 'programmes.
CONCLUSIONS The limitations of many current product design and development practices have proved a serious problem to the competitiveness of U K manufacturing industry. In order to be competitive, today's design engineers have to consider the overall scenario for a product (such as its use and function, the intended market place, its manufacture, etc.) just as the artisans of craft-based pre-industrial culture did. However, it must be recognized that modern product development is now beyond the capabilities of any one person. Ideally, the most effective response to this situation is for a forum of committed contributing experts that have mastered all the activities of the product development cycle, working in a concurrent design/manufacturing structure, who can guide a product from its inception through design and manufacture and thence into sales. Such an approach very closely models that of artisans except that instead of one individual crafting a product it is a team of carefully managed personnel who are all aware of each other's roles and tasks. Integration and communication within a firm, and with its customers, is both critical to the success or failure of a product. Such integration has, in the past, been singularly absent from the majority of UK firms but it has been contended in this paper that CAD is a means by which this integration can be facilitated. CAD offers a catalyst in which the design and manufacture functions can be integrated and so provide some certainty that what is designed can actually be made. It also provides an ideal working means for the simultaneous approach to product (and process) design. It must be borne in mind at all times that CAD by itself is only a tool - there has to be a conscious and explicit methodology which matches the existing company resources of people and technology to achievable products and market needs. REFERENCES Cross, N 'The changing design process', in Roy, R. and
Wield, D. (Eds.) Product design and technological innovat/on, Open University Press (1986) 2 Jones, J C Design methods, John Wiley and Sons, Chichester, UK (1980) Freeman, C 'Successful industrial innovation', in Roy, R.
and Wield, D. (Eds.) Product design and technological innovation, Open University Press (1986) 4 Burlington, M 'Strategy for design'. Proceedings of engineering design "86 congress, Birmingham, seminar 3A, 1986 5 Beitz, W 'Strategies for planning and developing innova-
Vol 11 No 4 October 1990
five market orientated products'. Proc sixth internatational conference on engineering design, Vol 1 (1989)pp 211-227 6 Gardiner, P and Rothwell, R Innovation, The Design Council, 1985 Liley, J E N 'The management of design'. Proc of sixth international conference on engineering design, Vol 1 (1989) pp 245-262 Putnam, A O 'A redesign for engineering'. Harvard
business review, 1985, pp 139-144 Wilson, P M and Greaves, J 'Forward engineering - a
strategic link between design and profit'. Proceedings of mechatronics conference (1989) 10 Ford, J C 'Simultaneous engineering (design to manufacture)'. Proceedingsof international bus, truck and car product and manufacturing technology exhibition and congress (1989) 11 Corbett, J 'Reduction of engineering timescales/ simultaneous engineering'. Proc. international bus, truck, and car product and manufacturing technol, exhibition and congress (1989) 12 King, J A 'Simultaneous engineering - how to make it work'. Proc. international bus, truck and car product and manufacturing technology exhibition and congress (1989) 13 Black, I 'Embodiment design: facilitating a simultaneous
approach to mechanical CAD'. Computer-aided eng J, Vol 7, No 2 (April 1990) pp 49-53 14 Rothwell, R, Gardiner, P and Schott, K Design and the
economy, The Design Council, London, UK (1983) 15 Pugh, S and Hollins, W Successful product design, Butterworths, Borough Green, UK (1990) 16 Black I and Murray, J L 'Concept embodiment - a
methodological basis for effective computer-aided design'. Proc of sixth international conference on engineering design Vol 2, (1989) pp 929-946 17 Corbett, J 'Design for economic manufacture'. Proc first conf. on the education and training of engineering designers (1983) pp 27-33 18 Oaldey, M Managing product design, Wiedenfield and
Nicholson, London, UK (1984) 19 Cross, N Engineering design methods, John Wiley and Sons,
Chichester, UK (1989) 20 Stark, J Managing CAD~CAM, McGraw-Hill, London, UK (1988) 21 Medland, A and BurneR, P CAD~CAM in practice: a manager's guide to understanding and using CAD~CAM, Kogan Page, London, UK (1986) 22 Stark, J What every engineer should know about practical CAD~CAM applications, Marcel Dekker (1986) 23 National Economic Development Council - design working party. A fiamework for communicating the full role of design in product development and innovation (1985) 24 Cross, J D and Black, I 'Putting the design into mechanical CAD: a company methodology', Design Studies, Vol 9, No 4 (October 1988) pp 214-218
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