concurrent engineering notes

7/23/2019 Concurrent Engineering Notes

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LECTURE ONE: INTRODUCTION

After this lecture you should understand the following:

Stages in the life cycle of a product

Characteristics of global competition Characteristics' of a competitive product Role of research and development in the design of products Factors influencing forward move of a product

1.0 The life cycle of a productWith customer reuirements changing over time! demand for particular product eventually falls and the organi"ationshould stop ma#ing it $e%g% computer software & upgraded every year! motor vehicles modified year after year% As a

result almost all products have a limited life span% (emand for most products follows a standard life cycle% )his has fivestages as shown in Figure l %*

Figure *%* +ife cycle of a product

I - IntroductionA new product appears on the mar#et and demand is low while people learn about it! try it and see if they li#e it $e%g%colour photocopiers! colour laser printers etc! at this stage the mar#eting department has a tas# of promoting the productand ensuring that sales growth begins%

II - Growth,ew customers buy the product and demand rises uic#ly $i%e% the new product is accepted by the mar#et ande-periences e-ponential growth% (uring this period however! competitors will have observed the success of the newproduct and this stimulates them to produce their own competing design%

III-Maturity.ost potential customers #now about the product and are buying it in steady numbers% (emand stabili"es at a constantlevel for instance motor vehicles! colour televisions sets%

IV-DeclineSales fall as customers start to buy new alternative products that become available%

V- Withdrawal(emand declines to the point where it is no longer worth to ma#e the product $e%g% blac# and white television sets! threewheel cars%

/lobal competition0p until the 12s when international competition was less fierce! product design from both the technological and

operations point of view was relatively simple% 3ngineers designed what they felt the customer needed% )hey had thenotion that the customer was not part and parcel of the design process% With time the scale of human activities has

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multiplied many fold bringing with it enormous business opportunities% )his naturally provo#ed competition amongmanufacturers! forcing design to be customer driven%.any manufacturers in developed countries decisively responded to this fierce competition by incorporating strategies

which would ensure success within a competitive environment! where the buying public has come to e-pect near perfectproducts with a high degree of dependability% +ess industrialised regions have been slow to incorporate such strategiesfor several reasons! hence their poor showing on both the domestic and international mar#ets%

4ighly specialised fields such as the automotive sector are dominated by products from regions such as 5apan% )his isbecause they have advanced product development systems in place% )heir good performance is due to the fact that theyattach great importance to scientific and technological education & an inevitable precondition to compete successfully%

Characteristics of a competitive productFrom an investor's perspective! a successful product development process must yield products that can be produced andsold profitably! yet profitability is often difficult to assess uic#ly and directly% Five specific dimensions! all of whichrelate to profit! are commonly used to assess the performance of a product development effort%

6roduct uality & how is the product resulting from the development effort7 (oes it satisfy customer needs7 8s it

robust and reliable7 6roduct uality is ultimately reflected in mar#et share and the price that customers are willing topay

6roduct cost & what is the manufacturing cost of the product7 )his cost includes e-penditure on capital euipment andtooling as well as the incremental cost of producing each unit of the product% 6roduct cost determines how much

profit accrues to the firm for a particular sales volume and a particular sales price% (evelopment time & how uic#ly did the team complete the product development effort7 (evelopment time

determines how responsive the firm can be to competitive forces and to technological developments! as well as howuic#ly the firm receives the economic returns from the team's efforts%

(evelopment cost & how much did the company have to spend to develop the product7 (evelopment cost is usually asignificant fraction of the investment reuired to achieve the profits%

(evelopment capability & are both team and firm better able to develop future products as a result of their e-periencewith a product development pro9ect7 (evelopment capability is an asset the firm can use to develop products more

effectively and economically in the future%4igh performance along these five dimensions should ultimately lead to economic success however! other performancecriteria are also important%Research and development: its role in product development)he role of research and development $R( in a company setting is essentially to enhance overall performance by

ensuring that new products are developed and e-isting ones redesigned to match changes in levels of technology andcustomer reuirements% Companies that commit substantial resources towards R( naturally #eep abreast with the latesttechnologies% Such technologies in turn support the development of great products% 8nvesting in R( has numerousadvantages as can be seen in Figure *%;%

Figure *%;


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$RODUCTDEVELO$MENT

Figure *%=: +ife&cycle of a product $office printersAs can be seen from Figure *%=! while typewriters were a hit in the printing industry! today they are the oldesttechnology and slowest! not very user friendly as compared to the other ranges of printers% 8nvesting in R( enabled

companies to come up with more versatile and reliable printing machines $e%g% laser printers)heoretically! a company which delays to launch new products after the decline and withdrawal of older products must

run out of business% Figure *%> illustrates product life cycle by loo#ing at related products that are at different stages% )heneed to #eep a range of products at different stages is also apparent% )his gives long&term stability with new customerdriven products being introduced while older ones are declining and being withdrawn% As s result overall production issmoothed rather than fluctuating as shown in Figure *%>%

Figure *%>: 8ntroduction and withdrawal of products $A & 3

R( maintains stable total output by on the one hand carrying out surveys to establish mar#et reuirements in terms ofproduct specifications which determine phasing in of new products! redesigning of already e-isting products andwithdrawal of older and declining products% ?n the other hand it researches on the latest trends of development in termsof product design techniues%Clearly! as illustrated in Figure *%@! two sets of forces influence the forward move of a product:

)echnology push

.ar#et pull

TECHNOLOGY

PUSH

MARKET PULL

6ossible )echnological 8mprovements 6ossible .ar#et (emands

(esign for .anufacture

CA(CA.

Buality Function (eployment

Rapid prototyping

.icroprocessor

+ow Cost

4igh Buality

0ser Friendliness

(ependability

3nvironmental Friendliness

Availability

Figure *%@: )echnology push and mar#et pull forces

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Exercises* (iscuss the phases in the life cycle of a product and say what implications they have in the design activity%; (iscuss the role of R( in product development and say what its bottom line implications are in a manufacturing

enterprise= What are the ma9or characteristics of a competitive product7

> /ive a brief description of technology push factors in product development and say how they influence the forwardmove of a product@ /ive a brief description of mar#et pull factors in product development and say how they influence the forward move

of a product

Reading list* (% Waters! ?perations .anagement! Addison Wesley! *1%; S% (% 3ppinger! D% )% 0lrich! 6roduct (esign and (evelopment! .c/raw 4ill! *@%=


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LECTURE TWO: CONCURRENT ENGINEERING

)he definition of concurrent engineering is a much&disputed sub9ect% )he essence of concurrent engineering is the

simultaneous rather than serial! e-ecution of various phases in the product development process% )he most important aimof concurrent engineering is shortening the development lead&time% Shortening development lead&time is in itself not agoal% A short development time has to be combined with competitive advantages% )hese advantages determine thesuccess of a product in the mar#et place% Conseuently! better customer orientation is a second goal of concurrentengineering% .ost of the time this means improved uality% +ower development cost is a third goal of concurrent

engineering% )his! of course has a strong relationship with a shorter development lead&time% )hese three goals are thebasic elements of the definition of concurrent engineering(efinitions of concurrent engineering vary! but most agree that the #ey concepts include:

)he use of a team approach to represent all aspects of the life cycle of the design

A focus an customer reuirements! and

0se of concurrent design process that includes early design of production and field support systems%

(esign methodology literature shows that the concept of concurrent engineering has not yet been fully understood% .ostphase models present the product development process as a serial chain of activities%

Figure ;%* shows the descriptive model of 6ahl and


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Figure ;%; .anufacturability System .odel

.ore recent literature deals with the concurrency of various phases% )he integrated 6roduct (evelopment $86( modelof Andreasen and 4ein $see Figure ;%=% )his model clearly shows the concurrency of mar#et development! productdevelopment and process development%

Figure ;%= 8ntegrated 6roduct (evelopment $86( model

)he 86(&model still distinguishes different phases in the development process% 8t shows! however! also concurrent flowsof activities% 3ach flow is dealing with specific sub9ects! resulting in one goal: putting a great product on the mar#et fast%

Organizing for Concurrent Engineering8mplementing concurrent engineering implies restructuring the product development process% )he order of activities intime has to be reconsidered% An analysis can indicate which tas#s can be carried out in parallel% )he interaction betweenthe various tas#s has to be defined% )hese interactions provide the necessary consensus and a chec# on the integrity ofthe product%

Concurrent Engineering Toolbox)a#ing into account all life cycle perspectives reuires structured wor#ing methods% Garious tools have been developedto support these wor#ing methods:

Buality Function (eployment $BF( is a tool to translate customer demands into functional reuirements%Rapid prototyping is a tool to produce prototypes in a matter of hours instead of wee#s%

Failure mode and 3ffect Analysis $F.3A is a method to detect possible failures of the product as early aspossible in the product creation process%Galue Analysis 3ngineering

Buality assurance & if a development process wisely specifies the phases a development pro9ect will pass through then

following the development process is clearly one way of assuring the uality of the resulting product%Co ordination & a clearly articulated development process acts as a master plan which defines the roles of each of theplayers on the development team%6lanning & a development process contains natural milestones corresponding to the completion of each phase% )he timingof these milestones anchors the schedule of the overall development pro9ect%.anagement & a development process is a benchmar# assessing the performance of an ongoing development effort%


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the product development process is as the initial creation of a wide set of alternative product concepts and thensubseuent narrowing of alternatives and increasing specifications of the product until the product can be reliably andrepeatedly produced by the production system%

Figure ;%= also identifies the #ey activities and responsibilities of the different functions of the organisation during eachdevelopment phase%)he testing and refinement phase involves the construction and evaluation of multiple pre&production versions of the

product% 6rototypes are usually built at this phase% 0sually these prototypes come in two versions: Alpha prototype & which are built with production intent parts i%e% parts with the same geometry and material

properties as intended for the production version of the product but not necessarily fabricated with the actual

processes to be used in production% Such prototypes are used to determine whether or not the product will wor# asdesigned and whether or not the product satisfies the #ey customer needs%


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.anufacturing

3stimatemanufacturingcost%Assessproduction

feasibility%

8dentifysuppliers for #eycomponents% 6erform ma#e&buy analysis%

(efine finalassemblyscheme%

(efine piece Ipart productionprocesses% (esign tooling% (efine uality

assuranceprocesses%


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)his approach can also be represented with a model as shown in Figure ;%@%

6R?(0C)(3S8/,

DD0808 8DC6R?(0C)

J C0S)?.3RC?.6A,K

L $6R?(%12A+S

(3S81,SMMM

M &J

t #

.A,0FAC)0R8,/

.A,0FAC)0R3(

Figure ;%@ Seuential product development model8n this system! the primary output is a prototype product delivered to customers! which meets their reuirements% )hesecondary output is a design delivered to manufacturing for production% )he designer receives very little feedbac#about how well the product meets customers' goals downstream when it is being manufactured%)he little involvement the designer has is directed at design modification% )he timing of these product design changes

during the product lifecycle has an enormous effect on overall business ob9ectives% .a9or changes in a product arecheaply and easily made during the initial design stages% As the product moves through its development stages! thecost and difficulty of ma#ing changes increases steadily%8mproving effectiveness of new product development reuires that the design manufacturing interface be vieweddifferently% )his approach is #nown as concurrent engineering%Concurrent engineering & a paradigm shift

Concurrent engineering is an approach where the product and all its associated processes! such as manufacturing!distribution! and service! are all developed in parallel% )ypically this involves cross&functional involvement early inthe product development pro9ect% Concurrent engineering has also come to be #nown as simultaneous engineering%)he ma9or goal of this approach is to progress in the design process concurrently $simultaneously to avoid costlymodifications downstream% Figure ;%1 shows a manufacturability system model.anufacturability system model

8n this approach! Figure ;%1! the design function is customer reuirements% 4owever the output is a manufacturabledesign and the customer of that product is internal & the manufacturing department% )his model has a #ey feedbac#loop that provides measures of the design manufacturability to the design function% )he difference from the traditionalapproach is that in this model manufacturing is the primary customer of the product design%


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Figure ;%E Simultaneous 3ngineering& using concurrency to develop fast cycle capability in product development%

3-ercises* (escribe the phases of a generic product development process; (escribe the phases of a generic product development process

= (iscuss the benefits of a well defined product development process@ 3-plain! giving e-amples! the following terminology with respect to product design and development: Customer driven products

)echnology push products 6latform products Customised products 6rocess intensive products1 With the aid of a manufacturability system model! e-plain what you understand by Concurrent engineeringE (iscuss the advantages of Concurrent 3ngineering over )raditional (esign approach

N 8n what way are the following manufacturability measures affected by design uality: Scrap level Availability Kield

(efects 8nventor

.anufacturing cost


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LECTURE T%REE CONCE$T DEVELO$MENT

At the end of this lecture you should understand the following:

Stages in the concept development phase 8mportance of mission statement in product development 6rocess of identifying customer reuirementsneeds )he Buality Function (eployment $BF( method

3.0 Concept Deelop!ent)he concept development phase is the starting point of product development% 8t contains the distinct activities shownin Figure =%*%

Figure =%*: Concept (evelopment

3.1 The "ission #tate!ent)he mission statement $Figure =%; also called a charter or design brief specifies which direction to go in but generallydoes not specify a precise destination or a particular way to proceed% )he mission statement could for instance specify

a particular mar#et opportunity and lay out the broad constraints and ob9ectives for the pro9ect% 8t may include some ofthe information:


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Figure =%;: .ission statement for a new product

3.$ %dentifying Custo!er &eeds)he results of this activity are the input into the ,eeds


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o e-press the need in terms of what the product has to do! not in terms of how it may do it

o e-press the need as specifically as the raw data

o e-press need as attribute of product

?rganise the needs into a hierarchy & the result of the preceding steps is a list of numerous need statements%)his is captured in the affinity diagram & Figure =%>% such a large number of detailed statements is aw#ward

to wor# with and also difficult to summarise for use% )he goal of this step is to organise these $statementsfrom affinity diagram into a hierarchical list called the tree diagram & Figure =%@

Figure =%>: Affinity (iagram)he tree diagram typically consists of a set of primary needs! each of which will be further characterised by a set ofsecondary needs% 8n cases of very comple- products the secondary needs may be further bro#en down into tertiaryneeds as well%

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Figure =%@ )ree (iagram

- $lannin2 Matri3

5ust as the Customer ,eeds


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Figure =%1 6lanning .atri-

C - Technical Re&)on&e&5ust as the Goice of the Customer had ualitative and uantitative components $entered into the Customer

needs


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Figure =%E Relationships Whats vs 4ows

E- Technical Correlation or !en&iti(ity Matri3 4%ow& (& %ow&5)his is the matri- firming the roof of the P4ouse of BualityP i%e% BF( chart% )he purpose of this matri- is to identifythe ualitative correlation between the technical responses $4ows% )his is a very important feature of the ualityhouse since! at times the possible solutions could be redundant and may not add much value to customer wants% Attimes it may be at cross purpose $in disagreement with each other% 8f two 4ows help each other meet their targetvalues $4ow&.uches! they are rated as positive or strong positive% 8f meeting one 4ow target value ma#es it harderor impossible to meet another 4ow target value $4ow .uch! those two 4ows are rated as negative or strongly

negative% A case in point is where 2&*22 #mh time and fuel economy are two uality items% 3fforts to decrease 2&*22#mh time would have an adverse effect on the fuel economy item% 8n this case! the two 4ows have a negativecorrelation7 Fuel economy and gross weight have a positive correlation because reducing gross weight will increasefuel economy #eeping all other remaining parameters constant% )hese relationships are weighted! and standard BF(uses the weights $for strong! = for medium and 2 for none% After all relationship matrices are developed! care is ta#enin reviewing its constructs%


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Figure =%N A completed BF( chart $4ouses of Buality for .ouse )rap


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Figure =%: BF( & the 4ouses


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uality with reference to the functions a product has to perform but this is one of the many functions that need tobe deployed during product development% With conventional deployment! it is difficult to address all aspects oftotal values management $)G. such as L&ability! cost! tools and technology! responsiveness and organisation

issues% 8t is not enough to deploy Buality into the product and e-pect the outcome to be b world&class% )G.efforts are vital in maintaining a competitive edge in today's world mar#etplace% )he uestion is how to deploy allthe aspects of this )G.%

)he method of deploying many competing values simultaneously is called Concurrent Function (eployment% )heintent of CF( is to incorporate Goice of the Customers into all nine phases of the product development cycle!through mission definition! concept definition! engineering and analysis! product design! prototyping! production

engineering and planning! production operations and control! manufacturing! and finally into continuousimprovement! support and delivery% 8n other words CF( is a customer driven 6(=

3-ercises*% 8n BF( there are > phases that deploy Goice of the Customer $G?C to get to an improved product% What are

the components of BF(7 3-plain each of the four BF( phases and give e-amples

;% 4ow can the Dano model be used to prioritise a set of customer reuirements $CRS7 4ow does a CR shiftcharacter7 When dose this happen

=% What are the rooms of 4?B7 Why are )echnical 8mportance Ratings $)8Rs listed under a 4?W&.0C4 listvector

>% What is the significance of weighting factors in computing )8Rs7 4ow can manufacturers use )8Rs toprioritise the uality characteristics of a product yet to be launched%

@% What are the limitations of deploying BF(7 What is reuired in optimising an artifact to be recognised as thebest in every class

1% 8n what way is BF( a concurrent engineering tool7E% What is CF(7 4ow does it differ from BF(7N% 6repare a Buality Function (eployment chart for a commercial product of your choice and comment on the

results%

Reading +ist* S%(% 3ppinger! D% )% 0lrich! 6roduct (esign and (evelopment! .c/raw 4ill! *@%;


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LECTURE /OUR CONCE$T GENER"TION


Concept generation methodology 6roblem decomposition scheme 8mportance of patent search as an information source Application of the concept classification tree

'.0 The tas( of Concept )enerationA product concept is an appro-imate description of the technology! wor#ing principles! and form of the product% 8t is aconcise description of how the product will satisfy the customer needs% A concept is usually e-pressed as a s#etch or

as a rough three&dimensional model and is often accompanied by a brief description% )he degree to which a productsatisfies customers and can be successfully commerciali"ed depends to a large measure on the uality of theunderlying concept% A good concept is sometimes poorly implemented in subseuent development phases! but a poor

concept can rarely be manipulated to achieve commercial success% 8n most cases! depending on the capability of thedevelopment team! numerous concepts are generated% ?f these only a few merit serious consideration during theconcept selection activity%

)horough e-ploitation of alternatives early in the development process greatly reduces the li#elihood that the teamwill stumble upon a superior concept late in the development process or that a competitor will introduce a productwith dramatically better performance than the product under development%Common dysfunctions e-hibited by development teams during concept generation include:

Consideration of only one or two alternatives often proposed by the most assertive members of the team%

Failure to consider carefully the usefulness of concepts employed by other firms in related and unrelatedproducts%8nvolvement of only one or two people in the process! resulting in lac# of confidence and commitment by therest of the team8neffective integration of promising partial solutions

Failure to consider entire categories of solutionsConcept generation methodology usually follows a five step methodology as illustrated in Figure >%*

'.1 The fie*step !ethodology(ifferent product development teams can always modify it to match their own reuirements% )he methodology brea#scomple- problems into simpler sub&problems! which are easier to analyse%

Solution concepts are then identified for the problems by e-ternal and internal search procedures! Classification treesand concept combination table are used to e-plore systematically the space of solution concepts and to integrate thesub&problem solutions into a total solution%

2;


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Figure >%* Five step concept generation methodology

!te) -Clari1y $ro6le'Clarifying the problem consists of understanding the problem and then brea#ing it down into sub&problems wheremore focus is placed% .ost designs are too comple- to solve as a single problem and hence the need to divide theminto several simpler sub&problems% )he brea#ing down of a problem into sub&problems is called problemdecomposition approach%

)he first step in decomposing a problem functionally is to represent it as a single blac# bo- as shown in Figure >%;%

)he blac# bo- represents the overall function of the product%

Figure >%; 6roblem decomposition & PoverallP Pblac# bo-P

)he ne-t step is to divide the single blac# bo- into sub&functions to create a more specific description of the functionsof different elements in the product% See Figure >%=% 3ach sub&function can be further bro#en down until it is simpleenough to wor# with% )he goal of these decomposition techniues is to divide a comple- problem into simpler

1> Clarify the Proble5"nderstandingProble5 deco5/osition-ocus on critical sub6/roble5s

2> Search e?ternallyLead users%?/ertsPatentsLiteratureench5arking

3> Search InternallyIndi4idualGrou/

Sub6/roble5s

> %?/lore syste5aticallyClassification treeCo5bination table

!> &eflect on the solutions and the /rocessConstructi4e feedback

%?isting Conce/ts

(ew Conce/ts

Integrated Solutions

In)ut

%nergy)@,

Material )nail,

Signal )tool Atri/B,

Hand6Held (ailer

Out)ut

%nergy )@,

Material )dri4en (ail,

Signal )@,

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problems such that these simpler problems can be tac#led in a focused way%

Figure >%= 6roblem decomposition into sub&functions

?nce the decomposition is complete! the team chooses the sub&problems that are most critical to the success of theproduct and that are li#ely to drive the overall solution to the problem%

!te) , - !earch E3ternally3-ternal search is aimed at finding solutions to both the overall problem and to the sub&problems identified during theproblem clarification step% Although it comes as a second step in the methodology! e-ternal search actually occursthroughout the development process% 8mplementing an e-isting solution is usually uic#er and cheaper thandeveloping a new solution% 0sing the e-isting solution allows the team more time to focus on the critical sub&problems! which have no e-isting solutions% 3-ternal search is an information gathering process% Five typical ways ofgathering information from e-ternal sources include:

+ead user interviews: lead users are those users of a class of product% 0sually! lead users go out of their way tomodify! if a product does not fulfil a given design function% Sometimes they could simply modify the product toaccommodate a function initially not designed into the product% )hese lead users stand to benefit substantially fromproduct innovation%Consulting e-perts: e-perts with #nowledge of one or more of the sub&problems not only can provide solution

concepts directly but also can redirect the search in a more fruitful area% /enerally e-perts may include professionalsat firms manufacturing related products! professional consultants! university faculties and technical representatives ofsuppliers% While finding e-perts consumes time! it is less time consuming than re&creating e-isting #nowledge%

Search patents: patents are a rich source of technical information containing detailed drawings and e-planations ofhow products wor#% )heir disadvantage however is that concepts found in recent patents are protected! so they may bea royalty involved in using them% )hey are however very useful to see what concepts are already protected and hence

must be avoided or licensed% Concepts contained in e-pired patents or patents without global coverage can be usedwithout paying royalties%Search published literature: published literature includes 9ournalsQ conference proceedingsQ trade maga"inesQgovernment reportsQ mar#et! consumer! and product information! and new product announcements% 3lectronicdatabase searches are also available for search purposes%


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there is need to ta#e time to evaluate our concepts% A better approach is for individuals perceivingwea#nesses in concepts to channel suggestions into improvements or alternative concepts%/enerate a lot of ideas & the more ideas a team generates! the more li#ely the team is to e-plore fully the

solution space%Welcome ideas that may seem infeasible & ideas that initially seem infeasible may be improved by othermembers of the team

0se graphical and physical media & reasoning about physical and geometric information with words isdifficult% )e-t and verbal language are inherently inefficient vehicles for describing physical entities%

Abundant s#etching is necessary% Foam! clay! cardboard! and other three& dimensional media may also be appropriateaids for problems reuiring a deep understanding of form and spatial relationships%8ndividual and group sessions & formal studies of group and individual problem solving suggests that a set of peoplewor#ing alone for a period of time will generate more and better concepts than the same people wor#ing together forthe same time period $ .c/rath & *N>% /roup sessions are more ideal for building consensus! communicatinginformation and refining concepts%

!te) 7 - E3)lore &y&te'atically)he result of the search activities are a collection of hundreds of concepts fragments & solutions to the sub&problems%

Systematic e-ploration is aimed at navigating the space of possibility by organising and synthesising the solutionfragments% 8n a typical product development pro9ect a team may come up with many concept fragments to each sub&problem% ?ne approach to organising and synthesising these fragments would be to consider all of the possible

combinations of the fragments associated with each sub&problem% )his approach would be very tedious% +ets supposethere were three sub&problems to be considered and for each of these sub&problems fifteen fragments are generated%)his implies that ==E@ combinations of fragments will have to be considered by the team% Among these! many of thecombinations might not ma#e sense% )here are two specific tools for managing this comple-ity and organising thethin#ing of concept generating team:

Concept classification tree

Concept combination table

Conce)t cla&&i1ication tree)he tree helps the team divide the possible solutions into independent categories% (ividing the solutions into severaldistinct classes facilitates comparison and pruning% Figure >%> shows an e-ample of classification tree for the hand

held nailer% )he branches of this tree correspond to different energy sources%

Figure >%> Classification tree for nailer energy 6roduct (esign! (evelopment and .anagement

Store or+cce/t%nergy

Pneu5atic

Hydraulic

(uclear

attery

all $utlet

%?/losi4e Syste5s

-uel6+ir Syste5s

%lectrical

Che5ical

-uel Cell

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)he classification tree has a number of benefits which include:6runing of less promising branches & if a solution approach does not appear to have much merit! then this

solution approach must be PprunedP allowing the team to focus its attention on more promising branches ofthe tree% 6runing must be done with a high degree of evaluation and 9udgement%3-posure of inappropriate emphasis on certain branches & once the tree is constructed! the team is able to

reflect uic#ly on whether the effort applied to each branch has been appropriately allocated% 8n the nailere-ample! the team realised that they had applied very little effort to thin#ing about hydraulic energy sourcesand conversion technologies% )his recognition guided them to focus on this branch of the tree for a few days%

Refinement of the problem decomposition for a particular branch & sometimes a problem decomposition canbe usefully tailored to a particular approach to the problem% Consider the branch of the tree corresponding tothe electrical energy source%


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Figure >%Ea Combination of: Solenoid & Spring & .ultiple 8mpacts

Figure >%Eb Combination of: Rotary .otor & Spring & Single 8mpact

Figure >%Ec Combination of: Rotary .otor & Spring & .ultiple 8mpacts

Figure >%Ed Combination of: +inear .otor & .oving .ass & Single 8mpact

2!


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3-ercises*% What do you understand by problem decomposition with respect to the concept generation methodology7

(iscuss one scheme by which a problem can be decomposed%;% (ecompose the problem of designing a new coffee tea ma#er% )ry using the functional decomposition

approach%

=% (evelop a classification tree for any two sub&problems for the coffeeteama#er>% 3-plain the purpose of the concept combination table and draw up the same for a sub&problem of the

coffeetea ma#er

@% What are the prospects of computer support for the concept generation activities71% (iscuss the five step concept generation methodology

Reading +ist* (% Waters! ?perations .anagement! Addison Wesley! *1%; S%(% 3ppinger! D% )% 0lrich! 6roduct (esign and (evelopment! .c/raw 4ill! *@%

=


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LECTURE /IVE CONCE$T !ELECTION


)he importance of concept selection in the concept development process

Concept selection methodology )he si-&step concept screening process )he si-&step concept scoring process Advantages of a structured concept selection methodology

+.0 Concept selection an integral part of the product deelop!entprocess

After identification of customer needs! the product development team generates alternative solution concepts in

response to these needs% Concept selection is the process of evaluating the generated concepts with respect to setcriteria% )he process involves comparing the relative strengths and wea#nesses of the concepts! and selecting one ormore concepts for further investigation or development%

While many stages of the concept development process benefit from unbounded creativity and divergent thin#ing!concept selection is the process of narrowing the set of concept alternatives under consideration% )he conceptselection process is iterative and usually does not produce a dominant concept immediately% +arge set of concepts is

initially winnowed down to a smaller set! but these concepts may subseuently be combined and improved% )hroughseveral iterations! a dominant concept is finally chosen% Figure @%* illustrates this successive narrowing and temporarywidening of the set of options under consideration during the concept selection activity%

Figure @%*: ,arrowing of concept options

Whether or not the concept selection process is e-plicit! all teams use some method to choose among concepts% 3venthose teams generating only one concept are using a method: choosing the first concept they thin# of% Figure @%;shows several concepts generated by a design firm for a medical supply company% )he medical supply companytas#ed the design firm to develop a reasonable syringe with precise dosage control for outpatient use% )o focus the

development effort! the first step was for the supply company to identify ma9or problems with its current product:&

Cost & e-isting model was made of stainless steel

Accuracy of the dose metering & e-isting model did not have a very accurate dose metering system%

)arget mar#et& the company also reuested that the product be tailored to the physical capabilities of the

elderly! an important segment of the target mar#et%

)o summarise the needs of its clients and intended users! the team established seven criteria on which the choice of aproduct concept would be based:& 3ase of handling 3ase of use Readability of dose settings

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(ose metering accuracy (urability 3ase of manufacture

6ortability

Figure @%= Concepts for outpatient syringe

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Figure @%= Concepts for outpatient syringe

2:


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+.1 #tructured Concept #election "ethodologyAll of the early phases of product development are influential on eventual product success% A structured conceptselection process helps to maintain ob9ectivity throughout the concept phase of the development process and guidesthe product development team through a critical and difficult process% )he structured concept selection methodologyoffers the following potential benefits:

A customer&focused product A competitive design


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minuses are selected%

Concepts

Selection Criteria A.aster

Cylinder

= @Sum ITs 2 ; = 2 * ; *

,et Score ; &* &; 2 * 2 2Ran# * 1 E = ; = =Continue7 Kes ,o ,o Combine Kes Combine Revise

Figure @%> Concept Screening .atri-

!te) 7- Co'6ine and I')ro(e the conce)t&4aving rated and ran#ed the concepts! the team verifies that the results ma#e sense and then considers if there are waysto combine and improve certain concepts% )wo issues considered in concept combinationare:&

8s there a good concept which is degraded by one bad feature7 Can a minor modification improve the overall

concept and yet preserve a distinction from the other concepts7

Are there two concepts which can be combined to preserve the Pbetter thanP ualities while annulling the

Pworse thanP ualities7From the e-ample in Figure @%*%> concepts ( and F could be combined to remove several of the Pworse thanP ratings toyield a new concept! (F! to be considered in the ne-t round% Concept / was also considered for revision% )he revisedconcepts are shown in Figure @%*%@%

!te) 8 - !elect one or 'ore conce)t&?nce the team members are satisfied with their understanding of each concept and its relative worth! they decide whichconcepts are to be selected for further refinement and analysis%

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Figure @%@ ,ew and Revised Concepts for Syringe

!te) - re1lect on the re&ult& and the )roce&&All of the team members should be comfortable with the outcome% 8f an individual is not in agreement with the decisionof the team! then perhaps one or more important criteria are missing from the screening matri-% An e-plicit considerationof whether the results ma#e sense to everyone reduces the li#elihood of ma#ing a mista#e and increases the li#elihoodthat the entire team will be solidly committed to the subseuent development activities%

8+,+, Conce)t !corin28n this stage! the team weigh the relative importance of the selection criteria and focuses on more refined comparisonswith respect to each criteria% )he concept scores are determined by the weighted sum of the ratings% Figure @%1 illustratesthe scoring matri- used in this stage%

!te) - $re)are the &election 'atri3As in the screening stage! the team prepares a matri- and identifies a reference concept% Concepts finding their way tothis stage are refined to some e-tent and may be e-pressed in more detail% 8n con9unction with more detailed concepts!the team may wish to add more detail to the selection criteria% )he use of hierarchical relations is a useful way toillustrate the criteria% For the syringe e-ample! suppose the team decided that the criterion Pease of useP did not provide

sufficient detail to help distinguish among the remaining concepts% P3ase of useP could be bro#en down! as shown inFigure @%E to include P ease of in9ectionP' Pease of cleaningP' and Pease of loadingP%After the criteria are entered! the team adds importance weights to the matri-% (ifferent schemes can be used to weighthe criteria! such as assigning an importance value from * to @! or allocating *22 percentage points among them! as inFigure @%1%

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Concepts

A (F 3 /

SelectionCriteria

Weight

$reference.aster Cylinder

+ever Stop Swash Ring (ial Screw

Rating Weighted Score Rating Weighted Score Rating Weighted Score Rating WeightedScore

3ase of handling @O = 2%*@ = 2%*@ > 2%; > 2%;

3ase of use *@ = 2%>@ > 2%1 > 2%1 = 2%>@

Readability ofsettings

*2 = 2%= = 2%= @ 2%@ @ 2%@

(ose meteringaccuracy

;@ = 2%E@ = 2%E@ ; 2%@ = 2%E@

(urability *@ = 2%>@ @ 2%E@ > 2%1 = 2%>@

3ase of manufacture

;2 = 2%1 = 2%1 ; 2%> ; 2%>

6ortability *2 = 2%= = 2%= = 2%= = 2%=

)otal Score =%22 =%>@ =%*2 =%2@

Ran# > * ; =

Continue7 ,o (evelop ,o ,o

Figure @%1 Concept Scoring

)he matri- in Figure @%1 uses concept A as a reference concept%

Figure @%E 4ierarchical decomposition of selection criteria

!te) , - Rate the conce)tAs in the screening stage! one way to rate the concept is to compare them to the reference concept%


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Finally! each concept is given a ran# corresponding to its total score! as shown in Figure @%1

!te) 7 - Co'6ine and I')ro(e the conce)t&As in the screening stage! the team loo#s for changes or combinations that improve concepts% Although the formalconcept generation process is typically completed before concept selection begins! some of the most creativerefinements and improvements occur during the concept selection process as the team realises the inherent strengths andwea#nesses of certain feature of the product concepts

!te) 8 - !elect one or 'ore conce)t&For the syringe e-ample! the team agreed that concept (F was the most promising and was li#ely to lead to a successfulproduct%

!te) - Re1lect on the re&ult& and the )roce&&)he final step is to reflect on the selected concept and the concept selection process

E3erci&e&*% (iscuss the concept selection process as an integral part of the product development process%

;% (iscuss the si-&step process followed in narrowing the number of concepts generated during productdevelopment%

=% (iscuss the si-&step process followed in selecting the most promising concept in the process of developing aproduct% What is the purpose of a reference concept7

>% 0sing the concept selection methodology! select the most promising from concepts you generated inproceeding e-ercise $concept generation%

@% What are the prospects for computer support of concept selection activities1% ?utline the concept selection methodology! with particular reference to concept screening and concept

scoring matrices%

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LECTURE !I; $RODUCT "RC%ITECTUREAfter this lecture you should understand the following : 6roduct architecture

8mplications of product architecture on the enterprise

6rocedures for establishing architecture

,.0 -hat is product architectureA product is always thought of in both functional and physical terms% )he functional elements of a product are theindividual operations and transformations that contribute to the overall performance of the product% Functional elementsare usually described in schematic form before they are reduced to specific technologies! components or physicalwor#ing principles%)he physical elements of a product are the parts! components! and subassemblies that ultimately implement the product'sfunctions%

)he physical elements of a product are typically organised into several ma9or physical building bloc#s! which we callchun#s% 3ach chun# is made up of a collection of components that implement the functions of the product%)he architecture of a product is therefore the scheme by which the functional elements of the product are arranged into

physical chun#s and by which the chun#s interact%A very important characteristic of a product's architect is its modularity% A modular architecture has the following twoproperties:&

Chun#s implement one or a few functions 8nteractions between chun#s are well definedSuch a modular architecture allows a design change to be made to one chun# without generally reuiring a change toother chun#s for the product to function correctly% )he chun#s may be designed uite independently of one another%)he opposite of a modular architecture is an integral architecture% An integral architecture e-hibits one or more of the

following properties:& Functional elements of the product are implemented using more than one chun# A single chun# implements many functional elements 8nteractions between chun#s are ill&defined

An e-ample of modular and integral architecture is shown in Figure 1%*

Figure 1%*


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function of the product% )he architecture of the product defines how these bloc#s relate to the function of the product%)he architecture therefore also defines how the product can be changed% .odular chun#s allow changes to be made to afew isolated functional elements of the product without necessarily affecting the design of other chun#s% Changing an

integral chun# may affect many functional elements and reuires changes to several related chun#s% Some of the motivesfor product change include:& product upgrade! addons! adaptation and wear% 8n each of these cases a modular architectureallows the firm to minimise the physical changes reuired to achieve a functional change%

6roduct varietyvariety refers to the range of product models the firm can produce within a particular time in response to mar#et demand%6roducts built around modular product architecture can be more easily varied without adding tremendous comple-ity to

the manufacturing system% A good e-ample is the swatch range of watches%

Swatch produces hundreds of different watch models! but can achieve this variety at relatively low cost by assemblingthe variants from different combinations of standard chun#s $Figure 1%;A large number of different hands! faces and wristbands can be combined to create endless combinations%

Figure 1%; Swatch uses a modular designComponent standardisation:& component standardisation is the use of the same component or chun# in multiple products%Such standardisation allows the firm to manufacture the chun# in higher volumes than would otherwise be possible% )his

in turn leads to lower costs and increased uality% Component standardisation may also occur outside the firm whenseveral manufacturer's products all use a chun# or component from the same supplier% A good e-ample is the battery ofthe watch in Figure 1%;! made by a supplier and standardised across several manufacturers' product lines%6roduct performance:& product performance is how well a product implements its intended functions% )ypicalperformance characteristics are speed! efficiency! life! accuracy and noise%An integral architecture facilitates the optimisation of those performance characteristics that are driven by the si"e and

mass of a product% Such characteristics includeQ acceleration! energy consumption! aerodynamic drag! noise andaesthetics% )he practice of implementing multiple functions using a single physical element is called function sharing%An integral architecture allows for redundancy to be eliminated through function sharing and allows for geometric

nesting of components to minimise the volume a product occupies% Clearly material utilisation is minimised and so aremanufacturing costs%.anufacturability:& ?ne important design of manufacturing $(F. strategy includes the minimisation of the number of

parts in a product through component integration% 4owever! to maintain a given architecture! the integration of physicalcomponents can only be easily considered within each of the chun#s% Component integration across several chun#s isdifferent! if not impossible! and would alter the architecture dramatically%

3stablishing the Architecture


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iv% identify fundamental and incidental interactions

E3erci&eWhat are the implications of degree of modularity to product architecture% What do you understand by productarchitecture7 3-plain using suitable e-amples

Readin2 Li&t* (% Waters! ?perations .anagement! Addison Wesley! *1%; S%(% 3ppinger! D% )% 0lrich! 6roduct (esign and (evelopment! .c/raw 4ill! *@%= +% Cohen! Buality Function (eployment! Addison Wesley! *@%*@ C% .c.ahon! CA(CA.! Addison Wesley! *N%

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LECTURE !EVEN INDU!TRI"L DE!IGNAfter this lecture you should understand the following: industrial design and its role in product design

the industrial design process

the management of the industrial design process

/.0 %ndustrial design and its i!portance to products)he birth of 8ndustrial (esign $8( is often traced to western 3urope in the early *N2s% 3uropeans believed a productshould be designed Pfrom the inside outP% Form should follow function% 8n the 0nited States the product's e-terior washeld more important and its insides mattered little% )his is evidenced in 0S products of the *=2s% From fountain pens tobaby buggies! products were designed with non&functional aerodynamic shapes in an attempt to create product appeal%)he auto industry provides another e-ample% )he shapes of 3uropean automobiles of the *=2s were fairly simple and

smooth! while 0S cars of the same era were decorated with such non&functional features as tailfins and chrome teeth%


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Figure E%* Concept s#etches showing two of the early concepts in the .icro)AC development pro9ect

Figure E%; 4ard model & after further refinement and final concept selection

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Figure E%= .icroUAC & Control drawing showing the final shape and dimensions%

.anagement of the industrial design process8ndustrial design may be incorporated into the overall product design process at any time during a developmentprogramme% )he timing of the 8( effort depends upon the nature of the product being designed% )o e-plain the timing ofthe 8( effort it is convenient to classify products according to the nature of the dominant challenges facing the

development team: achieving technological performance! designing the e-terior and user interfaces! or both%)echnology (riven 6roducts)he primary characteristics of a technology&driven product is that its core benefit is based on its technology! or its abilityto accomplish a specific technical tas#! while such product may still have important aesthetic and ergonomicreuirements! consumers will most li#ely purchase the product primarily for its technical performance%8t therefore follows that for the development team of a technology&driven product! the engineering or technical

reuirements will be paramount and will dominate development efforts% Accordingly the role of 8( 8 often limited topac#aging the core technology! which entails determining the product's e-ternal appearance and ensuring that theproduct communicates its technological capabilities and modes of interaction to the user%

0ser & (riven 6roducts)he core benefit of a user &driven product is derived from its interface andor its aesthetics appeal% )ypically there is ahigh degree of user interaction for these products% Accordingly the user interfaces must be safe! easy to use! and easy to

maintain% )he product's e-ternal appearance is often important to differentiate the product and create pride of ownership%While these products may be technically sophisticated! the technology does not differentiate the productQ thus! for the

;


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product development team! the 8( considerations will be more important than the technical reuirements% )he role ofengineering may still be important to determine any technical features of the product: however! since the technology isoften already established! the development team focuses on the user aspects of the product%

)echnology&and& 0ser&(riven 6roductsA technology&and &user&driven product is simply the combination of the above two categories% )hese products have ahigh degree of user interaction and have stringent technical performance reuirements% Figure E%> classifies a variety of

popular products%

Figure E%> Classification of some common products on the continuum from technology&driven to user&driven%,ote: rarely does a product fit e-actly into a given category% 8nstead most products fall somewhere along the continuum%

)hese classifications can be dynamic% For instance! when a company develops a product based on a new coretechnology! the company is often interested in bringing the product to mar#et as uic#ly as possible% Since little

emphasis is placed on how the product loo#s or is used! the initial role of 8( is small%4owever! as competitors enter the mar#et! the product may need to compete more along user or aesthetic dimensions%)he product's original classification shifts! and 8( assumes an e-tremely important role in the development process%A wal#man provides a good e-ample of a technology&and&user&driven product% )he core benefit of the first Wal#man$ e%g% Sony was its technology $ miniature tape player% As competition entered this mar#et! however! Sony relied veryheavily on 8( to create aesthetic appeal and enhanced utility! adding to the technical advantages of subseuent models%

concurrent engineering notes

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