2.2 Product-architecture.ppt

Product development

1. Product Architecture

2. Product Design and Development
Karl T. Ulrich and Steven D. Eppinger
2nd edition, Irwin McGraw-Hill, 2000.
Chapter Table of Contents
1.Introduction
2.Development Processes and Organizations
3. Product Planning
4.Identifying Customer Needs
5.Product Specifications
6.Concept Generation
7.Concept Selection
8. Concept Testing
9.Product Architecture
10. Industrial Design
11.Design for Manufacturing
12.Prototyping
13.Product Development Economics
14.Managing Projects

3. Planning
Product Development Process
Concept
Development
System-Level
Design
Detail
Design
Testing and
Refinement
Production
Ramp-Up
Product architecture is determined early in the development process.
Platform
decision
Concept
decision
Decomposition
decision

4. Product Architecture Example:
Hewlett-Packard DeskJet Printer

5. Product Architecture
•Aschemebywhichthefunctionalelementsofthe
productareassignedtophysicalbuildingblocks
(chunks)andbywhichtheblocksinteract.
•Eachchunkisthenmadeupofacollectionof
componentsthatimplementthefunctionsofthe
product.
•Thefunctionalelementsofaproductarethe
individualoperationsandtransformationsthat
contributetotheoverallperformanceoftheproduct.
•Thephysicalblocksofaproductaretheparts,
components,andsubassembliesthatultimately
implementtheproduct’sfunctions.

6. Product Architecture: Definition
Thearrangementoffunctionalelementsintophysical
chunkswhichbecomethebuildingblocksforthe
productorfamilyofproducts.
Product
module
module
module
module
module
module
module
module

7. considerations for product
architecture
•Howwillitaffecttheabilitytooffer
productvariety?
•Howwillitaffecttheproductcost?
•Howwillitaffectthedesignleadtime?
•Howwillitaffectthedevelopment
processmanagement?

8. Purpose of Product Architecture
•Todefinethebasicphysicalbuildingblocksofthe
productintermsofwhattheydoandwhattheir
interfacesaretotherestofthedevice.
•Architecturaldecisionsallowdetaileddesignand
testingofthesebuildingblocks
•Assignedtoteams,individuals,and/orsuppliers,
suchthatdevelopmentofdifferentportionsofthe
productcanbecarriedoutsimultaneously.

9. Two models of bicycle brake
and shifting control
•Inthetraditionaldesign(left),
theshiftcontrolfunction&the
brakecontrolfunctionare
allocatedtoseparatechunks-
modulararchitecture.
•Inthedesignontheright,the
shiftandbrakecontrol
functionsareallocatedtothe
same chunk-integral
architecture
InIntegralarchitecture-
Modificationstoanyoneparticular
componentorfeaturemayrequire
extensiveredesignoftheproduct.

10. Modular Design Displays the Following
Properties:
•Eachphysicalchunkimplementsoneorafewfunctional
elementsintheirentirety(eachfunctionalelementis
implementedbyexactlyonephysicalchunks).
•Theinteractionsbetweenchunksarewelldefined(i.e.
theinterfacesarewelldefined)

11. Integral Product Architectures
•Functionalelementsareimplementedbymultiple
chunks,orachunkmayimplementmanyfunctions.
•Interactionsbetweenchunksarepoorlydefined.
•Integralarchitecturegenerallyincreasesperformance
andreducescostsforanyspecificproductmodel.

12. Trailer Example:
Modular Architecture
box
hitch
fairing
bed
springs
wheels
protect cargo
from weather
connect to
vehicle
minimize
air drag
support
cargo loads
suspend
trailer structure
transfer loads
to road

13. Trailer Example:
Integral Architecture
upper half
lower half
nose piece
cargo hanging
straps
spring slot
covers
wheels
protect cargo
from weather
connect to
vehicle
minimize
air drag
support
cargo loads
suspend
trailer structure
transfer loads
to road

14. Types of Modularity
•Slot-Modular Architecture
-uniqueinterfacesforattachmenttoabaseelement
(e.g.radiosandspeedometershavedifferenttypesof
interfacestotheinstrumentpanel)
•Bus-Modular Architecture
-commoninterfacesforattachmenttoabase
element(e.g.USBconnectorsonacomputer)
•Sectional-Modular Architecture
–Common interfaces between elements without a
base element (e.g. legos& piping)

15. Implications of the Architecture
Decisionsabouthowtodividetheproductinto
chunksandabouthowmuchmodularitytoimposeon
thearchitecturearetightlylinkedtoseveralissuesof
importancetotheentireenterprise:
•Productchange
•Productvariety
•Componentstandardization
•Productperformance
•Manufacturability
•Productdevelopmentmanagement

16. Product Change
•Chunksarethephysicalbuildingblocksoftheproduct,but
thearchitectureoftheproductdefineshowtheseblocks
relatetothefunctionoftheproduct
Thearchitecturethereforealsodefineshowtheproductcan
bechanged.
•Upgrade(replacingapumpinacoolingsystemwithamore
powerfulmodel)
•Add-ons(third-partymassstoragedevicesmaybeaddedto
abasiccomputer)
•Adaptation(adapttodifferentoperationenvironments)-
Someenginescanbeconvertedfromagasolinetoa
propanefuelsupply.

17. Product Change Cont..
•Wear(e.g.,razors,tires,bearings)
•Consumption(forexample,tonercartridgesinprinter,
batteryincameras)
•Flexibilityinuse(foruserstoreconfiguretoexhibit
differentcapabilities)-manycamerascanbeused
withdifferentlensandflashoptions
•Reuseincreatingsubsequentproducts

18. Product Variety
•Varietyreferstotherange
ofproductmodelsthefirm
canproducewithina
particulartimeperiodin
response to market
demand.
•Productsbuiltaround
modular product
architecturescanbemore
easilyvariedwithoutadding
tremendouscomplexityto
themanufacturingsystem.

19. Component Standardization
•Componentstandardizationistheuseofthesame
componentorchunkinmultipleproducts.
•Ifachunkimplementsonlyoneorafewwidelyuseful
functionalelements,thenthechunkcanbestandardized
andusedinseveraldifferentproducts.
•Standardizationallowsthefirmtomanufacturethechunk
inhighervolumes.
•Thisinturnmayleadtolowercostsandincreasedquality.
•Forexample,thewatchbatteryshowninpreviouspicture
ismadebyasupplierandstandardizedacrossseveral
manufacturers’productlines.

20. Product Performance
•Productperformanceisdefinedashowwellaproduct
implementsitsintendedfunctions.
•Typicalproductperformancecharacteristicsare
speed,efficiency,life,accuracy,andnoise.
•Anintegralarchitecturefacilitatestheoptimizationof
holisticperformancecharacteristicsandthosethatare
drivenbythesize,shape,andmassofaproduct.

21. Product exhibits function sharing
•Aconventionalmotorcycle
architectureassignsstructural-
supportfunctionalelementtoa
framechunk&thepower-
conversionfunctionalelement
toatransmissionchunk.
•Architectureofthismotorcycle
assignsboththestructural-
supportfunctionandthe
power-conversionfunctionto
thetransmissionchunk.

22. Manufacturability
•Theproductarchitecturedirectlyaffectstheabilityof
theteamtodesigneachchunktobeproducedatlow
cost.
•Oneimportantdesign-for-manufacturing(DFM)
strategyinvolvestheminimizationofthenumberof
partsinaproductthroughcomponentintegration.
•Tomaintainagivenarchitecture,theintegrationof
physicalcomponentscanonlybeeasilyconsidered
withineachofthechunks.
•Componentintegrationacrossseveralchunksis
difficultandwouldalterthearchitecturedramatically

23. The concepts of integral and modular
apply at several levels:
•system
•sub-system
•component

24. Product Architecture =
Decomposition + Interactions
•Interactions
within chunks
•Interactions
across chunks

25. Product Development Management
•Modularandintegralarchitecturesdemanddifferent
projectmanagementstyles.
•Withamodulararchitecture,thegroupassignedto
designachunkdealswithknown,andrelativelylimited,
functionalinteractionswithotherchunks.
•Ifafunctionalelementisimplementedbytwoormore
chunks,asinsomeintegralarchitectures,detaildesign
willrequireclosecoordinationamongdifferentgroups.
•Firmsrelyingonoutsidesuppliersorona
geographicallydispersedteamoftenoptforamodular
architecture-developmentresponsibilitiescanbesplit.

26. Establishing the Architecture
•Theendresultofestablishingthearchitectureisan
approximategeometriclayoutoftheproduct,
descriptionsofthemajorchunks,anddocumentation
ofthekeyinteractionsamongthechunks.
Four-stepprocessforestablishingtheproduct
architecture:
•Createaschematicoftheproduct.
•Clustertheelementsoftheschematic.
•Createaroughgeometriclayout.
•Identifythefundamentalandincidentalinteractions.

27. Step 1 Creating a product schematic
•Createaschematicdiagramrepresentingthe
(physicalorfunctional)elementsoftheproduct,using
blocks,arrows,andothernotations.
1.Flowofforcesorenergy
2.Flowofmaterial
3.Flowofsignalordata
•Agoodruleofthumbistoaimforfewerthan30
elementsintheschematic,forthepurposeof
establishingtheproductarchitecture.

28. DeskJet Printer Schematic
Flow of forces or energy
Flow of material
Flow of signals or data
Store
Output
Store
Blank
Paper
Enclose
Printer
Provide
Structural
Support
Print
Cartridge
Position
Cartridge
In X-Axis
Position
Paper
In Y-Axis
Supply
DC
Power
“Pick”
Paper
Control
Printer
Command
Printer
Connect
to
Host
Communicate
with
Host
Display
Status
Accept
User
Inputs
Functional
or Physical
Elements

29. Step 2 Cluster the elements of schematic
•Thesecondstepofsettingproductarchitectureistocreate
groupsofelementsintheschematic.
•Thepurposeofthisstepistoarriveatanarrangementof
modulesbyassigningeachdesignelementtoamodule.
•Geometricintegrationandprecision(FortheDeskJetprinter,
thiswouldsuggestclusteringtheelementsassociatedwith
positioningthecartridgeinthex-axisandpositioningthepaper
inthey-axis).
•Function sharing (Single physical component can implement
several functional elements of the product)
•Capability of vendors
•Similarity of design or production technology

30. Step 2 Cluster the elements of
schematic Cont..
•Localization of design (or part) change
•Accommodating variety
•Enabling standardization
•Portability of the interfaces (interactions are easily
transmitted over large distances.)

31. Cluster Elements into Chunks
Store
Output
Store
Blank
Paper
Enclose
Printer
Provide
Structural
Support
Print
Cartridge
Position
Cartridge
In X-Axis
Position
Paper
In Y-Axis
Supply
DC
Power
“Pick”
Paper
Control
Printer
Command
Printer
Connect
to
Host
Communicate
with
Host
Display
Status
Accept
User
Inputs
Paper Tray
Print
Mechanism
Logic Board
Chassis
Enclosure
User Interface Board
Host Driver
Software
Power Cord
and “Brick”
Functional
or Physical
Elements
Chunks

32. Step 3
Geometrical Layout of the Deskjet
Printer

33. Step 4Identify the fundamental
and incidental interactions
Fundamental interactions
Those which connect the building blocks, such as
energy flows, material flows, and data flows.
Incidental interactions
Thosethatarisebecauseofgeometricarrangements
ofthebuildingblocks,suchasthermalexpansionor
heatdissipation

34. Incidental Interactions
Enclosure
Paper Tray
Chassis
Print
Mechanism
User Interface
Board
Logic
Board
Power Cord
and “Brick”
Host Driver
Software
Styling
Vibration
Thermal
Distortion
Thermal
Distortion
RF
InterferenceRF
Shielding

35. Delayed Differentiation
•Postponing the differentiation of a product until late in the supply
chain is called delayed differentiation or simply postponement.
•Itmayoffersubstantialreductionsinthecostsofoperatingthe
supplychain,primarilythroughreductionsininventory
requirements.
Twodesignprinciplesarenecessaryconditionsfor
postponement.
1.Differentiatingelementsmustbeconcentratedinoneorafew
chunks.
2. The product and production process must be designed so that the
differentiating chunks can be added to the product near the end
of the supply chain.

36. InscenarioA,thethreeversions
oftheprinteraredefinedduring
assembly,thentransported,and
finallypackaged.
Consideratwhatpointalongthe
supplychaintheproductisuniquely
definedasoneofthesethree
variants.
InscenarioB,theassemblyactivityis
dividedintotwostages,
mostoftheproductisassembledinthe
firststage,theproductisthen
transported,assemblyiscompleted,and
finallytheproductispackaged.
InscenarioB,thecomponents
associatedwithpowerconversionare
assembledaftertransportation,andso
theproductisnotdifferentiateduntil
neartheendofthesupplychain.

37. Platform planning
Trade-off decision between
Differentiation plan:
•Explicitlyrepresentsthewaysinwhichmultiple
versionsofaproductwillbedifferentfromthe
perspectiveofthecustomerandthemarket.
Commonality plan:
•Explicitlyrepresentsthewaysinwhichthedifferent
versionsoftheproductarethesamephysically.

39. Several guidelines for managing
trade off between differentiation and
commanality plan
•Platformplanningdecisionsshouldbeinformedby
quantitativeestimatesofcostandrevenueimplications:
Estimatingtheprofitcontributionfromaone-percentage
pointincreaseinmarketshareisausefulbenchmarkagainstthe
potentialincreaseinmanufacturingandsupply-chaincostsof
additionalversionsofachunk.
•Inestimatingsupply-chaincosts,theteammustconsiderthe
extenttowhichthedifferentiationimpliedbythedifferentiationplan
canbepostponedorwhetheritmustbecreatedearlyinthesupply
chain.

40. several guidelines for managing trade off between
differentiation and commanality plan
•Iterationisbeneficial:Inourexperience,teamsmakebetter
decisionswhentheymakeseveraliterationsbasedonapproximate
informationthanthedetailsduringrelativelyfeweriterations.
•Theproductarchitecturedictatesthenatureofthetrade-off
betweendifferentiationandcommonality:
Thenatureofthetrade-offbetweendifferentiationand
commonalityisnotfixed.
Generally,modulararchitecturesenableahigherproportionof
componentstobesharedthanintegralarchitectures.
Thisimpliesthatwhenconfrontedwithaseeminglyintractableconflict
betweendifferentiationandcommonality,theteamshouldconsider
alternativearchitecturalapproaches,whichmayprovideopportunities
toenhancebothdifferentiationandcommonality.

41. Fundamental Decisions
•Integral vs. modular architecture?
•What type of modularity?
•How to assign functions to chunks?
•How to assign chunks to teams?
•Which chunks to outsource?

42. Practical Concerns
•Planningisessentialtoachievethedesiredvariety
andproductchangecapability.
•Coordinationisdifficult,particularlyacrossteams,
companies,orgreatdistances.
•Specialattentionmustbepaidtohandlecomplex
interactionsbetweenchunks(systemengineering
methods).

43. System –Level Design Issues
•TheDeskJetPrinterschematicshowsonlythekeyelementsof
theproduct.
•Therearemanyotherfunctionalandphysicalelementsnot
shown,someofwhichwillonlybeconceivedanddetailedasthe
system-leveldesignevolves.
•Theseadditionalelements-thesecondarysystemsofthe
product.
Examplesincludesafetysystems,powersystems,status
monitors,andstructuralsupports.
•Fortunately,secondarysystemsusuallyinvolveflexible
connectionssuchaswiringandtubingandcanbeconsidered
afterthemajorarchitecturaldecisionshavebeenmade.

44. DeskJet Printer Schematic
Flow of forces or energy
Flow of material
Flow of signals or data
Store
Output
Store
Blank
Paper
Enclose
Printer
Provide
Structural
Support
Print
Cartridge
Position
Cartridge
In X-Axis
Position
Paper
In Y-Axis
Supply
DC
Power
“Pick”
Paper
Control
Printer
Command
Printer
Connect
to
Host
Communicate
with
Host
Display
Status
Accept
User
Inputs
Functional
or Physical
Elements

45. Establishing the Architecture of
the Chunks
•Someofthechunksofacomplexproductmaybe
verycomplexsystemsintheirown.
•Forexample,manyofthechunksintheDeskJet
printerinvolvedozensofparts.
•Eachofthesechunksmayhaveitsown
architecture—theschemebywhichitisdividedinto
smallerchunks.
•Carefulconsiderationofthearchitectureofthe
chunksisnearlyasimportantasthecreationofthe
architectureoftheoverallproduct.

46. Establishing the Architecture
of the Chunks –Cont..
•Forexample,theprintcartridgeconsistsofthe
subfunctionsstoreinkanddeliverinkforeachoffour
colorsofink.
•Severalarchitecturalapproachesarepossibleforthis
chunk,including,forexample,theuseof
independentlyreplaceablereservoirsforeachink
color.

47. Creating Detailed Interface
Specifications
•Asthesystem-leveldesignprogresses,the
fundamentalinteractionsindicatedbylinesonthe
schematicarespecifiedasdetailedcollectionsof
signals,materialflows,andexchangesofenergy.
•Thespecificationoftheinterfacesbetweenchunks
shouldalsobeclarified.
•Forexample,Exhibit10-14showspossible
specificationofaninterfacebetweenablackprint
cartridgeandalogicboardforaprinter.

48. Specification of interface between black
print cartridge and logic board
Figure 10-14

49. Product Architecture: Conclusions
•Architecturechoicesdefinethesub-systemsand
modulesoftheproductplatformorfamily.
•Architecture determines:
–ease of production variety
–feasibility of customer modification
–system-level production costs
•Key Concepts:
–modular vs. integral architecture
–clustering into chunks
–planning product families

50. Thank You