LECTURE ONE: INTRODUCTION After this lecture you should understand the following: • Stag Stages es in the the lif lifee cyc cycle le of a pro produ duct ct • Char Charac acte teri rist stic icss of glo globa ball comp compet etit itio ion n • Char Charac acte teri rist stic ics' s' of a comp compet etit itiv ivee produ product ct • Role Role of rese researc arch h and develo developme pment nt in the design design of of produ products cts • Facto Factors rs influe influenci ncing ng forwa forward rd move move of of a produc productt
1.0 The life cycle of a product With customer reuirements changing over time! demand for particular product eventually falls and the organi"ation should 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 five stages as shown in Figure l %*
Figure *%*
+ife cycle of a product
I - Introduction A 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 product and 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 and e-perienc e-periences es e-ponentia e-ponentiall growth% growth% (uring (uring this period however however!! competitor competitorss will have observed observed the success success of the new product and this stimulates stimulates them to produce their own own competing design%
III-Maturity .ost potential customers #now about the product and are buying it in steady numbers% (emand stabili"es at a constant level for instance motor vehicles! colour televisions sets%
IV-Decline Sales 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! three wheel cars% /lobal competition 0p 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 the notion that the customer was not part and parcel of the design process% With time the scale of human activities has
1
multiplied many fold bringing with it enormous business opportunities% )his naturally provo#ed competition among manufacturers! manufacturers! 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 perfect products with a high degree of dependability% dependability% +ess industrialised regions have been slow to incorporate such strategies for 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 is because they have advanced product development systems in place% )heir good performance performance is due to the fact that they attach great importance to scientific and technological education & an inevitable precondition to compete successfully% successfully% Characteristics of a competitive product From an investor's perspective! a successful product development process must yield products that can be produced and sold profitably! yet profitability is often difficult to assess uic#ly and directly% Five specific dimensions! all of which relate to profit! are commonly used to assess the performance performance of a product development effort% •
6roduct 6roduct uality & how is the product resulting resulting from from the development development effort7 effort7 (oes it satisfy satisfy customer customer needs7 needs7 8s it robust and reliable7 6roduct uality is ultimately reflected in mar#et share and the price that customers are willing to pay • 6roduct cost & what is the manufacturing cost cost of the product7 product7 )his cost cost includes e-penditure e-penditure on capital euipment euipment and tooling as well as the incremental cost of producing each unit of the product% 6roduct cost determines how much profit accrues accrues to the firm for a particular particular sales volume and and a particular sales price% price% • (evelopme (evelopment nt time & how uic#ly uic#ly did the team complete complete the product product developm development ent effort7 effort7 (evelopm (evelopment ent time determines how responsive the firm can be to competitive forces and to technological developments! as well as how uic#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 (evelopment cost is usually usually a significant fraction of the investment reuired to achieve the profits% • (evelopment capability capability & are both both team and firm firm better able to develop future future products as as a result of their e-perience with a product development pro9ect7 (evelopment capability is an asset the firm can use to develop products more effectively effectively and economically in the future% 4igh performance along these five dimensions should ultimately lead to economic success however! other performance criteria 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 and customer reuirements% Companies that commit substantial resources towards R( naturally #eep abreast with the latest technologies% Such technologies in turn support the development of great products% 8nvesting in R( has numerous advantages as can be seen in Figure *%;%
U!INE!! "! U!U"L Shrinking Markets Higher Costs Loss of Profits
INVE!TMENT IN R#D Increased Market share Lower Costs Greater Profitability
Current Position
Figure *%;
R( is a process via which a company identifies mar#et reuirements and uses these ideas to design new products% Such a process improves overall company productivity and ensures a substantial rise in total turnout% Research and development achieves this via a wide range of its functions% )o understand understand some of these functions! we ta#e a loo# at the life cycle of a product & office printers! Figure Figure *%=%
2
Figu Figure re *%=: *%=: +ife& ife&cy cycl clee of of a prod produc uctt $of $office ice pri print nter ers s As can be seen from Figure *%=! while typewriters were a hit in the printing industry! today they are the oldest technology 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% )he need to #eep a range of products at different stages is also apparent% )his gives long&term stability with new customer driven products being introduced while older ones are declining and being withdrawn% As s result overall production is smoothed rather than fluctuating as shown in Figure *%>%
Figu Figure re *%>: *%>:
8ntro ntrodu duct ctio ion n and and withd ithdra rawa wall of of pro produ duct ctss $A $A & 3
R( maintains stable total output by on the one hand carrying out surveys to establish mar#et reuirements in terms of product specifications which determine phasing in of new products! redesigning of already e-isting products and withdrawal of older and declining products% ?n the other hand it researches on the latest trends of development in terms of product design techniues% Clearly! Clearly! as illustrated in Figure *%@! two sets of forces influence the forward move of a product: • )echnolo )echnology gy push • .ar#et pull
TECHNOLOGY PUSH
$RODUCT DEVELO$MENT
6ossible )echnological 8mprovements (esign for .anufacture CA(CA. Buality Function (eployment Rapid prototyping .icroprocessor • • • • •
MARKET PULL
6ossible .ar#et (emands +ow Cost 4igh Buality 0ser Friendliness (ependability 3nvironmental Friendliness Availability • • • • • •
Figur iguree *%@ *%@::
)echno chnolo logy gy push push and mar#et #et pu pull forc orces
3
Exercises * ; = > @
(iscuss (iscuss the phases phases in the life life cycle cycle of a product product and and say what what implica implications tions they they have have in the design design activit activity% y% (iscuss (iscuss the role role of R( R( in product product developm development ent and say say what what its bottom bottom line implic implications ations are are in a manufa manufactur cturing ing enterprise What What are the the ma9or ma9or char charact acter erist istics ics of a comp competi etitiv tivee produc product7 t7 /ive a brief brief descrip description tion of technolog technology y push factor factorss in product product developmen developmentt and say how they they influenc influencee the forward forward move of a product /ive a brief brief descript description ion of mar#et mar#et pull factor factorss in product product development development and and say how they they influence influence the forw forward ard move move of a product
Reading list * ; = > @
(% Wate Waters! rs! ?pera ?perations tions .anagemen .anagement! t! Addiso Addison n Wes Wesley ley!! *1% *1% S% (% 3pping 3ppinger! er! D% )% )% 0lrich 0lrich!! 6roduct 6roduct (esign (esign and and (evelopme (evelopment! nt! .c/raw .c/raw 4ill! 4ill! *@% *@% <% 6rasad 6rasad!! Concurre Concurrent nt 3ngineer 3ngineering ing Fundam Fundamental entals! s! 6rentic 6renticee 4all 4all 6)R! 6)R! *E% *E% <% +illy +illy!! (esign (esign for .anufactur .anufacturing: ing: +ectur +ecturee ,otes! ,otes! ?hio State State 0niver 0niversity sity!! *% S% Damban Dambani! i! ,% 5% Dwenda Dwenda#we #wema ma!! )he )he Role Role of R( in 3conom 3conomic ic (evelop (evelopmen ment! t! )he 3nginee 3ngineerin ring g 8nstituti 8nstitution on of ambia! *@%
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 aim of concurrent engineering is shortening the development lead&time% Shortening development lead&time is in itself not a goal% A short development time has to be combined with competitive advantages% )hese advantages determine the success of a product in the mar#et place% Conseuently! better customer orientation is a second goal of concurrent engineering% .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 the basic 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% .ost phase models present the product development process as a serial chain of activities% Figure ;%* shows the descriptive model of 6ahl and
Figure ;%* & 6ahl and
!
C"S#$M%& &%'"I&%M%(#S
*%SIG(S
*%SIG(
P&$*"C#
M+("-+C#"&I(G
C"S#$M%& )P&$*"C# G$+LS,
*%SIG( C&I#%&I+
C/02 -%%& P+&#S
*%-%C# L%.%LS
M+("-+C#"&+ILI# M%+S"&%S
Figure ;%; .anufacturability System .odel .ore recent literature deals with the concurrency of various phases% )he integrated 6roduct (evelopment $86( model of Andreasen and 4ein $see Figure ;%=% )his model clearly shows the concurrency of mar#et development! product development 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 flows of activities% 3ach flow is dealing with specific sub9ects! resulting in one goal: putting a great product on the mar#et fast%
Organizing for Concurrent Engineering 8mplementing concurrent engineering implies restructuring the product development process% )he order of activities in time has to be reconsidered% An analysis can indicate which tas#s can be carried out in parallel% )he interaction between the various tas#s has to be defined% )hese interactions provide the necessary consensus and a chec# on the integrity of the product%
Concurrent Engineering Toolbox )a#ing into account all life cycle perspectives reuires structured wor#ing methods% Garious tools have been developed to 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 as possible 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 the players on the development team% 6lanning & a development process contains natural milestones corresponding to the completion of each phase% )he timing of 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%
Phase 1 Conce/t de4elo/5ent Figure ;%;
Phase 2 Syste56Le4el *esign
Phase 3 *etail *esign
Phase #esting and &efine5ent
Phase ! Production &a5/6"/
A product development process
A typical product design process! generic product development process! is illustrated in Figure;%=% )he process consists of five phases% )he input is a mission statement and the output of the process is the product launch% ?ne way of imaging 7
the product development process is as the initial creation of a wide set of alternative product concepts and then subseuent narrowing of alternatives and increasing specifications of the product until the product can be reliably and repeatedly produced by the production system% Figure ;%= also identifies the #ey activities and responsibilities of the different functions of the organisation during each development 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# as designed and whether or not the product satisfies the #ey customer needs% •
Concept (evelopment
System&+evel (esign
(etail (esign
)esting Refinement
and 6roduction Ramp&0p
.ar#eting •(evelop • 6lace early (efine mar#et (evelop plan for (evelop product options mar#eting plan% promotion and production with segments% e-tended launch materials% #ey customers% 8dentify and product family% • Facilitate field lead users% testing% 8dentify competitive products%
•
•
•
(esign 8nvestigate • /enerate • (efine part feasibility of alternative geometry% product product • Choose concepts% architectures% materials% (evelop • (efine ma9or • Assign industrial design sub&systems and tolerances% concepts% interfaces% • Complete •
• (o reliability 3valuate early testing! life testing! production and performance output% testing% • ?btain regulatory approvals% • 8mplement design changes%
8
.anufacturing • 3stimate manufacturing cost% •Assess production feasibility%
•8dentify • (efine piece I • Facilitate
?ther Functions
Figure ;%=
• Finance: • Finance: Facilitate Facilitate ma#e& economic buy analysis% analysis% • Service: • +egal: 8dentify service 8nvestigate issues patent issues A generic product development process
• Sales: (evelop sales plan%
)he generic development process is most li#ely the process to be used in a mar#et&pull situation% A firm begins product development with a mar#et opportunity and then see#s out whatever technologies are reuired to satisfy the mar#et need $i%e% the mar#et pulls the product development decisions%
% •
•
•
•
Figure ;%> seuential product developments
9
)his approach can also be represented with a model as shown in Figure ;%@%
6R?(0C) (3S8/,
DD0808 8DC 6R?(0C)
(3S81 ,S MMM M &J
C0S)?.3
J C0S)?.3R C?.6A,K L $6R?(% 12A+S t
#
.A,0FAC)0 R8,/ .A,0FAC)0 R3(
Figure ;%@ Seuential product development model 8n this system! the primary output is a prototype product delivered to customers! which meets their reuirements% )he secondary 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 are cheaply and easily made during the initial design stages% As the product moves through its development stages! the cost and difficulty of ma#ing changes increases steadily% 8mproving effectiveness of new product development reuires that the design manufacturing interface be viewed differently% )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 in the 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 costly modifications 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 manufacturable design 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 traditional approach is that in this model manufacturing is the primary customer of the product design%
.anufacturability system model
.anufacturability measures are the factory's indicator on how well it is producing products that meet product goals% (esign criteria strongly affect product manufacturability% A product's technical performance is always by design and manufacturing% 8f a customer reuests a product that has a dimension of *2mm! the product must be designed and manufactured to that dimension% ?ther manufacturability measures that are strongly affected by design include: yield! scrap! inventory! cycle time! manufacturing costs ?verall! all manufacturability measures are interrelated% Kield affects cost and inventory levels% (efect levels! or defects per unit is one measure that has a strong influence on all manufacturability measures% 8t affects product uality! reliability! availability! cost etc% Figure ;%E shows how traditional design core has transformed into a simultaneous engineering based one%
:
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 products 1 With the aid of a manufacturability system model! e-plain what you understand by Concurrent engineering E (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
Reading list * (% Waters! ?perations .anagement! Addison Wesley! *1% ; S%(% 3ppinger! D% )% 0lrich! 6roduct (esign and (evelopment! .c/raw 4ill! *@% = <% 6rasad! Concurrent 3ngineering Fundamentals! 6rentice 4all 6)R! *E% > <% +illy! (esign for .anufacturing: +ecture ,otes! ?hio State 0niversity! *% 1 +%Cohen! Buality Function (eployment! Addison Wesley! *@% E C% .c.ahon! CA(CA.! Addison Wesley! *N%
1;
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 shown in Figure =%*%
Mi&&ion !tate'ent
Identify Custo5er (eeds
%stablish #arget S/ecifications
Generate Product Conce/ts
Select a Product Conce/t
&efine S/ecifi cations De(elo)'ent $lan
+naly
Figure =%*:
Perfor5 %cono5ic +nalysis
Plan &e5aining *e4elo/5en t Pro=ect
Concept (evelopment
3.1 The "ission #tate!ent )he mission statement $Figure =%; also called a charter or design brief specifies which direction to go in but generally does not specify a precise destination or a particular way to proceed% )he mission statement could for instance specify a particular mar#et opportunity and lay out the broad constraints and ob9ectives for the pro9ect% 8t may include some of the information:
6roduct (escription Dey
6rimary .ar#et Secondary .ar#ets Assumptions
Sta#eholders
.ission Statement: Screwdriver 6ro9ect A hand&held! power&assisted device for installing threaded fasteners 6roduct introduced in fourth uarter of *E @2O gross margin *2O share of cordless screwdriver mar#et by * (o&it&yourself consumer Casual consumer +ight&duty professional 4and&held 6ower&assisted ,ic#el&metal&hydride rechargeable battery technology 0ser Retailer Sales force Service center 6roduction +egal department
11
Figure =%;: .ission statement for a new product
3.$ %dentifying Custo!er &eeds )he results of this activity are the input into the ,eeds
*+,+ .uality /unction De)loy'ent Buality Function (eployment $BF( is a method for structured product planning and development that enables a development team to specify clearly the customer's wants and needs and then to evaluate each proposed product or service capability systematically in terms of its impact on meeting those needs% )he process involves constructing one or more matrices $sometimes called uality tables% )he first of these matrices is called the 4ouse of Buality $4?B% 8t displays the customer's wants and needs $Goice of Customer along the left and development team's response to meeting these wants and needs along the top% )he matri- consists of several sections or sub&matrices 9oined together in various ways! each containing information relating to others% 3ach of these labelled sections A through F is a structured systematic e-pression of a product or process development team's understanding of an aspect of the overall planning of product or process% )he lettering seuence as illustrated in Figure =%= suggests a logical seuence for filling in the matri-%
Figure =%=: )he 4ouse of Buality
" - Cu&to'er Need&0ene1it& )his is the starting place for all BF( activities% )he common source of customer phrases representing their wants and needs is the customer interview% )he usual steps in identifying customer needs are: /athering raw data from the customer& this is usually done by conducting interviews! where the result of such an activity is a set of customer phrases representing the customer's wants and needs% .ost companies have special departments for handling complaints since they represent a ma9or nightmare to any company & the nightmare of customer dissatisfaction% )oo often companies regard complaint management as their uality control mechanism% Dano suggests that it is not enough to ma#e a company competitive & however removing dissatisfiers from a product is a necessary if not a sufficient step to competitiveness% 4ence it is very useful to include customer complaints in the complete voice of the customer% 8nterpret raw data in terms of customer needs & customer needs are e-pressed as written statements% )hey result from interpreting the need underlying the raw data gathered from the customers% 3ach statement can be translated into several needs% /eneral guidelines of e-pressing the need could be for instance: 12
o o o
e-press the need in terms of what the product has to do! not in terms of how it may do it e-press the need as specifically as the raw data 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 $statements from 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 of secondary needs% 8n cases of very comple- products the secondary needs may be further bro#en down into tertiary needs as well%
13
Figure =%@
)ree (iagram
- $lannin2 Matri3 5ust as the Customer ,eeds
1
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
D - Relation&hi)& 4etween Cu&to'er Need& and Technical Re)on&e& What& (& %ow&5 )o get a relationship between mar#et reuirements and uality characteristics a matri- is created by placing the Whats list along the column of a matri- and the 4ows list along its rows as illustrated in Figure =%E% )he intersection of the rows and the columns then depicts the relationships between the set of Whats and the 4ows% )he matri- thus developed is called a Relationship .atri-% 8t correlates what customers want in a product and how an enterprise can achieve those ob9ectives% Relationships within this matri- are usually defined using a level procedure:& strong! medium! wea#! or none% )he matri- maybe densely populated $ more than one row or column affected% )his results from the fact that some of the uality solutions may affect more than one customer ,eed $What%
1!
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 identify the ualitative correlation between the technical responses $4ows% )his is a very important feature of the uality house since! at times the possible solutions could be redundant and may not add much value to customer wants% At times it may be at cross purpose $in disagreement with each other% 8f two 4ows help each other meet their target values $4ow&.uches! they are rated as positive or strong positive% 8f meeting one 4ow target value ma#es it harder or 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 negative correlation7 Fuel economy and gross weight have a positive correlation because reducing gross weight will increase fuel 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#en in reviewing its constructs%
/- Technical Matri3 4%ow-Muche&5: )his is a list vector and normally identifies the bounds on the feasibility on )echnical Responses $4ows% )hese represents the target values for each )echnical Response% 8n other words for each technical $4ow the e 8 a coEespondi B ; for a 4ow & .uch entry% )he idea is to uantify the solution parameters into achievable rangesH or specifications! thereby creating a criterion for assessing success% )his information is often obtained through mar#et evaluation and research% What are target specifications& Customer needs! in the manner they are e-pressed! leave too much margin this reason! development teams usually establish a set of specifications! which spell out in precise! measurable detail what the product has to do%
17
Figure =%N
A completed BF( chart $4ouses of Buality for .ouse )rap
18
Figure =%: BF( & the 4ouses
Li'itation& o1 ./D When many 5apanese producers became successful in bringing cars to mar#et in record time! many automotive world leaders mista#enly assumed that their success was solely because of technical tools% )his e-plains the initial flurry of activities $BF(! )aguchi! 6ugh! Dai"en etc that American industries went through during the *N2s% As many companies failed on this front% )hey discovered that many of the barriers to global competitiveness were rooted in their assumptions that are! basing their 6(= decisions on uality while ignoring other important aspects such as cost! design for L&ability! tools and technology! and infrastructure that have not been deployed simultaneously% BF( does not specifically address the cost! tools and technology! responsiveness $time&to&mar#et! and organi"ational aspects in the same vein as it addresses the uality aspect% While some consider the product design process as being independent from technology! design for L&ability! cost and responsiveness! the reality is that these are tied together by a common set of product and process reuirements% )he design process only provides a product design from the perspectives of performance $i%e% uality% )he product design performance reuirements drive the product selection process! including system! subsystems! components! parts and material selection! and influence the selection of the fabrication method! process and production% ?thers have argued that while performing Buality F(! designers could choose to include reuirements that belong t o considerations other than uality in the original customers' list of 4?B% Accomplishing this through a conventional deployment process is not simple% Wor#ing on the multiple lists of reuirements as part of a single function deployment is much tougher problem% • First! it would be a comple- underta#ing considering 9ust the si"e of the resulting relational matrices • Second! deploying them serially would be a long! drawn&out process • )hird! cascading the reuirements all together as we did in the case of Buality functions would be so large that it would be difficult to handle% • Fourth! there is no way of insuring that the design obtained through this combinatorial Buality F( process would not result in a sub&optimised design! that is a product particularly designed for characteristics related to uality% What is reuired in optimising an artifact is designing with respect to all important functions that characterise a world&class product today% .a9or pitfalls of BF( approach are: • Conventional deployment is mainly Buality focused: one of the pitfalls of conventional deployment is that it is based on a single measurement! which has mostly been uality% )oday manufacturing sectors are more fiercely competitive and global than ever% Consumers are more demanding! competition is more global! fierce! and ruthless! and technology is advancing and changing rapidly% )he uality based philosophy inherent in Buality F( style does not account for the time factor inherent in today's comple- 6(= process% Competitors are always finding better ways of doing things&catching up in uality is not enough% 8t only ma#es a company at par with its competitors in terms of inheriting some of their product characteristics% What is reuired is a total control of one's process & identifying and satisfying the needs and e-pectations of consumers better than the competitors and doing so profitably faster than any competitor% •
•
Conventional deployment is a phased process: the conventional deployment process prescribes a set of structured cross&functional planning and communication matrices for building uality as specified by customers into a product% )his is often represented in a cascade time bound process where characteristics of a prior phase feed as reuirements for a subseuent phase% )he serial nature of deployment tends to ma#e the BF( process seuential% 8f each phase of deployment is a multi&part prcess! the elapsed time can be significantly large% )his elongates the total time this BF( would ta#e for an artifact realisation process Conventional deployment is one&dimensional: the roles of the organisation and engineers are changing toady! as are the methods of doing business% Competition has driven organisation to consider concepts such as time compression $fast&to&mar#et! concurrent engineering! design for L&ability! and tools and technologies $such as )aguchi! Galue engineering while designing and developing an artifact% Buality F( addresses ma9or aspects of
19
uality with reference to the functions a product has to perform but this is one of the many functions that need to be deployed during product development% With conventional deployment! it is difficult to address all aspects of total 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 all the aspects of this )G.% )he method of deploying many competing values simultaneously is called Concurrent Function (eployment% )he intent 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 continuous improvement! 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 shift character7 When dose this happen =% What are the rooms of 4?B7 Why are )echnical 8mportance Ratings $)8Rs listed under a 4?W&.0C4 list vector >% What is the significance of weighting factors in computing )8Rs7 4ow can manufacturers use )8Rs to prioritise the uality characteristics of a product yet to be launched% @% What are the limitations of deploying BF(7 What is reuired in optimising an artifact to be recognised as the best in every class 1% 8n what way is BF( a concurrent engineering tool7 E% What is CF(7 4ow does it differ from BF(7 N% 6repare a Buality Function (eployment chart for a commercial product of your choice and comment on the results% Reading +ist * S%(% 3ppinger! D% )% 0lrich! 6roduct (esign and (evelopment! .c/raw 4ill! *@% ; <% 6rasad! Concurrent 3ngineering Fundamentals! 6rentice 4all 6)R! *E% = (% Waters! ?perations .anagement! Addison Wesley! *1% > <% +illy! (esign for .anufacturing: +ecture ,otes! ?hio State 0niversity! *% @ +%Cohen! Buality Function (eployment! Addison Wesley! *@% 1 C% .c.ahon! CA(CA.! Addison Wesley! *N% E 5%R% 4auser and (on Clausing! )he 4ouse of Buality! 4arvard
1:
LECTURE /OUR CONCE$T GENER"TION After this lecture you should understand the following: • 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 )eneration A product concept is an appro-imate description of the technology! wor#ing principles! and form of the product% 8t is a concise 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 product satisfies customers and can be successfully commerciali"ed depends to a large measure on the uality of the underlying 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 the development team! numerous concepts are generated% ?f these only a few merit serious consideration during the concept selection activity% )horough e-ploitation of alternatives early in the development process greatly reduces the li#elihood that the team will stumble upon a superior concept late in the development process or that a competitor will introduce a product with 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 unrelated products% 8nvolvement of only one or two people in the process! resulting in lac# of confidence and commitment by the rest of the team 8neffective integration of promising partial solutions Failure to consider entire categories of solutions Concept 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#s comple- 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 trees and concept combination table are used to e-plore systematically the space of solution concepts and to integrate the sub&problem solutions into a total solution%
2;
1> Clarify the Proble5 "nderstanding Proble5 deco5/osition -ocus on critical sub6/roble5s Sub6/roble5s
2> Search e?ternally Lead users %?/erts Patents Literature ench5arking
3> Search Internally Indi4idual Grou/
(ew Conce/ts %?isting Conce/ts > %?/lore syste5atically Classification tree Co5bination table
Integrated Solutions !> &eflect on the solutions and the /rocess Constructi4e feedback
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 where more focus is placed% .ost designs are too comple- to solve as a single problem and hence the need to divide them into several simpler sub&problems% )he brea#ing down of a problem into sub&problems is called problem decomposition 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%
In)ut
Out)ut
%nergy)@,
%nergy )@, Hand6Held (ailer
Material )nail, Signal )tool Atri/B,
Material )dri4en (ail, Signal )@,
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 functions of different elements in the product% See Figure >%=% 3ach sub&function can be further bro#en down until it is simple enough to wor# with% )he goal of these decomposition techniues is to divide a comple- problem into simpler
21
problems such that these simpler problems can be tac#led in a focused way%
%nergy
Store or acce/t e?ternal energy
Con4ert energy to translational energy
Store nails
Isolate nail
(ails
A#ri/B of #ool
Figure >%=
Sense tri/
+//ly translational energy to nail
*ri4en (ail
#rigger tool
6roblem decomposition into sub&functions
?nce the decomposition is complete! the team chooses the sub&problems that are most critical to the success of the product and that are li#ely to drive the overall solution to the problem%
!te) , - !earch E3ternally 3-ternal search is aimed at finding solutions to both the overall problem and to the sub&problems identified during the problem clarification step% Although it comes as a second step in the methodology! e-ternal search actually occurs throughout the development process% 8mplementing an e-isting solution is usually uic#er and cheaper than developing 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 of gathering 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 to modify! if a product does not fulfil a given design function% Sometimes they could simply modify the product to accommodate a function initially not designed into the product% )hese lead users stand to benefit substantially from product 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 professionals at firms manufacturing related products! professional consultants! university faculties and technical representatives of suppliers% 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 of how products wor#% )heir disadvantage however is that concepts found in recent patents are protected! so they may be a 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 used without paying royalties% Search published literature: published literature includes 9ournalsQ conference proceedingsQ trade maga"inesQ government reportsQ mar#et! consumer! and product information! and new product announcements% 3lectronic database searches are also available for search purposes%
Step 3 - Search Internally 8nternal search is the use of personal and team #nowledge and creativity to generate solution concepts% /uidelines for improving both individual and internal search include: Suspend 9udgement & because we have to live with the conseuences if product concept decisions for years
22
there is need to ta#e time to evaluate our concepts% A better approach is for individuals perceiving wea#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 other members of the team 0se graphical and physical media & reasoning about physical and geometric information with words is difficult% )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 appropriate aids 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 people wor#ing alone for a period of time will generate more and better concepts than the same people wor#ing together for the same time period $ .c/rath & *N>% /roup sessions are more ideal for building consensus! communicating information 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 solution fragments% 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 suppose there 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 the combinations might not ma#e sense% )here are two specific tools for managing this comple-ity and organising the thin#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 several distinct 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%
Che5ical
Pneu5atic
-uel6+ir Syste5s
%?/losi4e Syste5s
Store or +cce/t %nergy Hydraulic all $utlet
attery (uclear
%lectrical -uel Cell
Figure >%>
Classification tree for nailer energy 6roduct (esign! (evelopment and .anagement
23
)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 of the 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 nailer e-ample! the team realised that they had applied very little effort to thin#ing about hydraulic energy sources and 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 can be usefully tailored to a particular approach to the problem% Consider the branch of t he tree corresponding to the electrical energy source% %@% )he sub& function in this case was added after the conversion of the energy to mechanical energy% Figure >%@ identifies sub&problems of the electrical energy source%
%lectrical %nergy
Con4ert %nergy to #ranslational %nergy
+ccu5ulate #ranslational %nergy
+//ly #ranslational %nergy to (ail
%nergy +//lied to (ail
Figure >%@ 3lectrical energy source sub&problem
Conce)t Co'6ination Ta6le )he concept combination table provides a way to consider combinations of solution fragments systematically% Figure >%1 shows an e-ample of a combination table that the nailer team used to consider the combinations of the fragments for the electrical branch of the classification tree% )he columns in the table correspond to the sub&problems identified as indicated in Figure >%@% )he entries in each column correspond to the solution fragments for each of these sub& problems derived from e-ternal and internal search% For e-ample! the sub&problem of converting electrical energy to translational energy is the heading for the first column% )he entries in this column are a rotary motor with a transmission! a linear motor! a solenoid! and a rail gun as illustrated in Figure >%Ea&>%Ed 6otential solutions to the overall problem are formed by combining one fragment from each column% 8n the nailer e-ample there are ;> possible combinations% )he combination of fragments must be developed and refined before an integrated solution emerges% Convert 3lectrical 3nergy to )ranslational 3nergy
Accumulate 3nergy
Apply )ranslational 3nergy to ,ail
Rotary motor transmission
Spring
Single impact
.oving mass
.ultiple impacts
with
+inear motor
Solenoid
6ush nail
Rail gun
Figure >%1 Concept combination table
2
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!
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 activities7 1% (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! *@% = <% 6rasad! Concurrent 3ngineering Fundamentals! 6rentice 4all 6)R! *E% > <% +illy! (esign for .anufacturing: +ecture ,otes! ?hio State 0niversity! *% @ +%Cohen! Buality Function (eployment! Addison Wesley! *@% 1 C% .c.ahon! CA(CA.! Addison Wesley! *N%
27
LECTURE /IVE CONCE$T !ELECTION After this lecture you should understand the following: • )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!ent process 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 set criteria% )he process involves comparing the relative strengths and wea#nesses of the concepts! and selecting one or more 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 concept selection 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% )hrough several iterations! a dominant concept is finally chosen% Figure @%* illustrates this successive narrowing and temporary widening 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% 3ven those 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 company tas#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 a product concept would be based:& • 3ase of handling • 3ase of use • Readability of dose settings • • •
28
• • • •
(ose metering accuracy (urability 3ase of manufacture 6ortability
Figure @%=
Concepts for outpatient syringe
29
Figure @%=
Concepts for outpatient syringe
2:
+.1 #tructured Concept #election "ethodology All of the early phases of product development are influential on eventual product success% A structured concept selection process helps to maintain ob9ectivity throughout the concept phase of the development process and guides the product development team through a critical and difficult process% )he structured concept selection methodology offers the following potential benefits: • A customer&focused product • A competitive design •
+.$ Concept #election "ethodology A two&stage concept selection methodology! $proposed by 0lrich and 3ppinger is discussed% )his methodology is illustrated in Figure @%;% )he first stage is called concept screening and the second is called concept scoring% 3ach is supported by a decision matri- which is used by the team to rate! ran# and select the best concept$s% )he methodology of concept selection helps to manage the comple-ity of evaluating do"ens of product concepts% Screening is a uic#! appro-imate evaluation aimed at producing a few viable alternatives! while scoring is a careful analysis of these relatively few concepts in order to choose the single concept most li#ely to lead to product success% (uring concept screening rough initial concepts are evaluated relative to a common reference concept using the screening matri-% At this stage detailed uantitative comparisons are difficult to obtain and may be misleading! so a comparative rating system is used% After some alternatives are eliminated! the team can then move on to concept scoring and conduct more detailed analysis and finer uantitative evaluation of the remaining concepts using the scoring matri- as a guide% )hroughout the screening and scoring process! several iterations may be performed! with new alternatives arising from the combination of the features of several concepts%
8+,+ Conce)t !creenin2 Concept screening is based on a method developed by the late Stuart 6ugh in the N2s & 6ugh Concept Selection% )he purposes of this stage are to narrow the number of concepts uic#ly and to improve the concepts% Figure @%*%> shows the screening matri- used during this stage%
!te) - $re)are the &election 'atri3 4ere a matrice similar to one illustrated in Figure @%*%> may be used% Selection criteria are chosen based or customer needs the team will have identified as well as on the needs of the enterprise $eg% +ow manufacturing cost or minimal ris# of product liability% After careful consideration! the team chooses a concept to become the benchmar# or reference concept against which all other concepts are rated% )his reference is generally either an industry standard or an obvious solution to the problem% 8t can be a commercially viable product! an earlier generation of the product! any one of the concepts under consideration! or a combination o subsystems combined to represent the best features of different products%
!te) , - Rate the conce)t& A relative score of Pbetter thanP $! Psame asP $2! or Pworse thanP $& is placed in each cell of the math depending upon how the concept rates in comparison to the reference concept relative to the particular criterion%
!te) * - Ran9 conce)t& After rating all the concepts! the team sums the number of Pbetter thanP! Psame asP scores and enters the matri- sum for each category in the lower rows of the matri-% A net score can be calculated by subtracting the number ofP worse thanP ratings from the Pbetter thanP ratings% ?nce this summation is completed! the team ran#&orders the concepts and hence concepts with more pluses than 3;
minuses are selected% Concepts Selection Criteria
A < .aster Rubber Cylinder
3ase of handling 3ase of use Readability of settings (ose metering 2 2 accuracy (urability 2 2 3ase of & manufacture 6ortability Sum Hs ; * Sum 2Hs @ > Sum ITs 2 ; ,et Score ; &* Ran# * 1 Continue7 Kes ,o Figure @%> Concept Screening .atri-
C Ratchet
3 Swash Ring
F +ever Set
/ (ial Screw
& &
( $reference 6lunge Stop 2 2 2
2 2
& 2
& 2
2
2
2
2
2 &
2 2
2 2
&
2 2
2 * = = &; E ,o
2 2 E 2 2 = Combine
; > * * ; Kes
2 ; = ; 2 = Combine
2 * @ * 2 = Revise
!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 ways to combine and improve certain concepts% )wo issues considered in concept combination are:& 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 ualities7 From the e-ample in Figure @%*%> concepts ( and F could be combined to remove several of the Pworse thanP ratings to yield a new concept! (F! to be considered in the ne-t round% Concept / was also considered for revision% )he revised concepts 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 which concepts are to be selected for further refinement and analysis%
31
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 decision of the team! then perhaps one or more important criteria are missing from the screening matri-% An e-plicit consideration of whether the results ma#e sense to everyone reduces the li#elihood of ma#ing a mista#e and increases the li#elihood that the entire team will be solidly committed to the subseuent development activities%
8+,+, Conce)t !corin2 8n this stage! the team weigh the relative importance of the selection criteria and focuses on more refined comparisons with respect to each criteria% )he concept scores are determined by the weighted sum of the ratings% Figure @%1 illustrates the scoring matri- used in this stage%
!te) - $re)are the &election 'atri3 As in the screening stage! the team prepares a matri- and identifies a reference concept% Concepts finding their way to this 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 to illustrate 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 in Figure @%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 weigh the criteria! such as assigning an importance value from * to @! or allocating *22 percentage points among them! as in Figure @%1%
32
Concepts
Selection Criteria
Weigh t
A
(F
3
/
$reference .aster Cylinder Rating Weighte d Score
+ever Stop
Swash Ring
(ial Screw
Rating
Weighte d Score
Rating
Weighte d Score
Rating
Weighted Score
3ase of handling
@O
=
2%*@
=
2%*@
>
2%;
>
2%;
3ase of use Readability of settings (ose metering accuracy (urability 3ase of manufacture 6ortability
*@ *2
= =
2%>@ 2%=
> =
2%1 2%=
> @
2%1 2%@
= @
2%>@ 2%@
;@
=
2%E@
=
2%E@
;
2%@
=
2%E@
*@ ;2
= =
2%>@ 2%1
@ =
2%E@ 2%1
> ;
2%1 2%>
= ;
2%>@ 2%>
*2
=
2%=
=
2%=
=
2%=
=
2%=
)otal Score
Figure @%1
=%>@
=%*2
=%2@
Ran#
=%22 >
*
;
=
Continue7
,o
(evelop
,o
,o
Concept Scoring
)he matri- in Figure @%1 uses concept A as a reference concept%
%ase of In=ection
%+S% $- "S%
%ase of Cleaning
%ase of Loading Figure @%E 4ierarchical decomposition of selection criteria
!te) , - Rate the conce)t As in the screening stage! one way to rate the concept is to compare them to the reference concept% .uch better than reference concept @
!te) * Ran9 the Conce)t& ?nce the ratings are entered for each concept! weighted scores are calculated by multiplying the new scores by the criteria weights% )he total score for each concept is the sum of the weighted scores: n
S j ∑ r ij wi i =*
where r ij &raw rating of concept j for the ith criterion wiQ & weighting for i th criterion n& number of criteria S j & total score for concept j
33
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 formal concept generation process is typically completed before concept selection begins! some of the most creative refinements and improvements occur during the concept selection process as the team realises the inherent strengths and wea#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 successful product%
!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& *% ;% =% >% @% 1%
(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 product development% (iscuss the si-&step process followed in selecting the most promising concept in the process of developing a product% What is the purpose of a reference concept7 0sing the concept selection methodology! select the most promising from concepts you generated in proceeding e-ercise $concept generation% What are the prospects for computer support of concept selection activities ?utline the concept selection methodology! with particular reference to concept screening and concept scoring matrices%
3
LECTURE !I; $RODUCT "RC%ITECTURE After this lecture you should understand the following : • 6roduct architecture • 8mplications of product architecture on the enterprise • 6rocedures for establishing architecture
,.0 -hat is product architecture A product is always thought of in both functional and physical terms% )he functional elements of a product are the individual operations and transformations that contribute to the overall performance of the product% Functional elements are usually described in schematic form before they are reduced to specific technologies! components or physical wor#ing principles% )he physical elements of a product are the parts! components! and subassemblies that ultimately implement the product's functions% )he physical elements of a product are typically organised into several ma9or physical building bloc#s! which we call chun#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 two properties:& • Chun#s implement one or a few functions • 8nteractions between chun#s are well defined Such a modular architecture allows a design change to be made to one chun# without generally reuiring a change to other 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%*
8mplications of the architecture (ecisions about how much modularity to impose on the architecture are lin#ed to several issues of importance to the entire enterprise:& • 6roduct performance • 6roduct change • 6roduct variety • Component standardisation • .anufacturability 6roduct change chun#s are physical bloc#s of the product! but the architecture of the product defines how these bloc#s relate to the
3!
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 a few 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 motives for product change include:& product upgrade! addons! adaptation and wear% 8n each of these cases a modular architecture allows the firm to minimise the physical changes reuired to achieve a functional change% 6roduct variety variety 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 assembling the 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 design Component 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 when several manufacturer's products all use a chun# or component from the same supplier% A good e-ample is the battery of the 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% )ypical performance 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 and aesthetics% )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 are manufacturing 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 physical components can only be easily considered within each of the chun#s% Component integration across several chun#s is different! if not impossible! and would alter the architecture dramatically%
3stablishing the Architecture
37
iv% identify fundamental and incidental interactions
E3erci&e What are the implications of degree of modularity to product architecture% What do you understand by product architecture7 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! *@% <% 6rasad! Concurrent 3ngineering Fundamentals! 6rentice 4all 6)R! *E% <% +illy! (esign for .anufacturing: +ecture ,otes! ?hio State 0niversity! *% +% Cohen! Buality Function (eployment! Addison Wesley! *@% C% .c.ahon! CA(CA.! Addison Wesley! *N%
38
LECTURE !EVEN INDU!TRI"L DE!IGN After 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 product should be designed Pfrom the inside outP% Form should follow function% 8n the 0nited States the product's e-terior was held more important and its insides mattered little% )his is evidenced in 0S products of the *=2s% From fountain pens to baby 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%
39
Figure E%*
Figure E%;
Concept s#etches showing two of the early concepts in the .icro)AC development pro9ect
4ard model & after further refinement and final concept selection
3:
Figure E%=
.icroUAC & Control drawing showing the final shape and dimensions%
.anagement of the industrial design process 8ndustrial design may be incorporated into the overall product design process at any time during a development programme% )he timing of the 8( effort depends upon the nature of the product being designed% )o e-plain the timing of the 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 ability to accomplish a specific technical tas#! while such product may still have important aesthetic and ergonomic reuirements! 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 to pac#aging the core technology! which entails determining the product's e-ternal appearance and ensuring that the product 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 a high 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 ;
