Designfor innovation drives assembly....partof the design process." Design for assembly drives innovation, especially with a new vehicle program. At the onset of the $350 million EVI

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•By Kami Buchholz, Detroit Editor Design for innovation drives assembly.

I nitial vehicle designs drive profitmargins. "Product design, which ac-counts for only 5% of a product'stotal cost, actually dictates about 75% ofthe product's total accounted manufac-turing cost," stresses Sandy Munro,President of Munro & Associates, Inc., aTroy, MI-based concurrent engineeringconsultant firm. In workshops withautomakers and suppliers, Munro andstaff hark a simple message: always con-sider the total picture. "You cannot stopthe design process. Once you've passedgates, you can't go back. It's a one-waytrip early on," Munro says.

Workshops by Munro & Associateschallenge product engineers to assembletheir own designs. Class time also is de-voted to pooling the input and resources ofengineering and manufacturing to im-prove an existing product. For instance,about six years ago a class assignment hada product design engineer, a manufactur-ing engineer, an hourly factory worker,and finance and purchasing represen-tatives redesigning an ll-piece armrestbracket assembly into a one-piece entity(currently on a number of General Motorsvehicles).

The ll-piece steel and aluminum arm-rest bracket required a stamping die, aswage tool, a riveting tool, a high-speedproduction press, a secondary swage, asecondary press, a palletized conveyingsystem, and ample factory floor space. Incontrast, the one-piece armrest bracketcondensed manufacturing's contributionto a plastic blow molding machine. Thedesign change also reduced costs by 76%.

"You can always fix a design at anystage, but it's impossible to make modifi-cations later in the process without thosechanges resulting in huge capital expendi-tures and an expensive product," Munroasserts. Early involvement of suppliers isalso critical. "It's very important that thesupplier be involved. They know thingsthe OEM doesn't. Supplier participation ispart of the design process."

Design for assembly drives innovation,especially with a new vehicle program. Atthe onset of the $350 million EVI program,150 people - including GM engineers,

manufacturingengineers, mate-rial engineers, fi-nance represen-tatives, and sup-pliers - trainedand practicedover a six month-period on designfor assembly dy-namics. "Wehadprogressiveminded peoplepa rticipa ting,and that was fur-ther supportedby good leader-ship," explainsDavid Grieco, Manager EVl-5.0 ProductEngineering for GM Advanced Technol-ogy Vehicles. "One of the keys to oursuccess was combining the training withapplication. In the first (training) sessionwe developed some metrics, well beforethere were any designs. The foundationof manufacturing teclmical specificationsis influenced by design for assembly re-quirements," notes William Szkodzinski,Manager Manufacturing Engineering forGM Advanced Technology Vehicles.

Training time allowed product devel-opment teams to address assembly re-quirements up front. "DFA (design forassembly) flushes out a lot of issues," saysGrieco. "It has to do with team consensus,and listening to the ideas of people out-side the engineering group." Interlockingproduct engineering with manufacturingprovided the framework for new tech-nologies. (EV1 carries 23 new patents.)For instance, the 1997 EV1's patentedfront and rear shock towers are a singlepiece as opposed to a conventionalmultipiece construction requiring severalstamping welds. Although the entire ve-hicle was subjected to the process, threeareas where DFA had great influence onEV1 were: structure, chassis, and interior.

EV1's structural elements are joinedby 2000 spot welds, 40% fewer than atypical steel structure. About one quarterof the electric car's all-aluminum struc-ture is made of folded parts (including the

central tunnel and rear cross member).Single and multi-cell extrusions compriseanother quarter of the parts, while the re-maining structural components are cast-ings. The entire structure, secured by spotwelds, rivets, and aerospace adhesivebonding, has a mass of 131 kg. Conven-tional stampings were used for half of thevehicle's total part count. Because manu-facturing aspects spurred part consolida-tion and reduction, EV1's space frame ex-emplifies simplicity. Consider, for ex-ample, the integration of 24 separate sheetmetal pieces into four castings, which at-tach chassis springs and shock absorbers tothe space frame. In total, EV1 uses 165formed parts.

The multitude of one-piece snap-onparts, extrusions, and foldings that makeEV1 an engineering benchmark are pos-sible because design engineers looked atmanufacturing considerations from dayone. "The principles of DFA can be usedfrom the concept phase up. Others maysay, 'You have to have the designs in place:But you really don't," Szkodzinski says.EV1 also realized plant floor benefits asthe design of tooling was driven bymanufacturability. "If we didn't design forassembling the EV1, then the plant layoutwould be radically different - probablytwice as large and more complicated," as-serts Grieco. The Lansing (MI) Craft Centreassembly area for EV1 covers 10,200 m2

Layout of the assembly processes - paper

Reprinted with permission from Automotive Engineering, August 1997

at the process level," Heithaus says. Byinvolving manufacturing early, prod-uct engineers were able to evaluatepart and tooling designs while consid-ering the aspects of assembly line mo-tion and line height.

"The key is the timing, so engineer-ing can see early on what needs to berefined," Kingsley says. Lessonslearned by using a paper factory havebeen incorporated into a best practiceslean manufacturing guidebook forother GM plants. Although computersoftware programs playa valuable rolein the design process, GM's "paperwall" is considered invaluable. "Froman engineering standpoint, it's alwaysvisible. If it's in a computer, manytimes you only bring it up when you'rein that section. You have to see what'sgoing on with both sides, and 'the wall'provides the opportunity to see the en-tire sequence of how parts are put on avehicle," Kingsley says. ConcursHeithaus: "As programs get to fasterand faster timetables, you don't havetime to argue whose point is valid.With this ('the wall'), there's an under-standing of engineering and manufac-turing and what they do. The wholeprocess is enhanced because both sidesare meeting together, and both sidessee what is actually going on."

Ford Motor Company's integratedcomputer-aided design, engineering,manufacturing and product informationmanagement system - known as C3P -gives the automaker the distinction of be-ing the first auto manufacturer to use com-puter simulations for designing its finalvehicle assembly processes globally. Thedigital vehicle buck and the digital factoryare two elements of C3P that link engi-neering and manufacturing. "Manufac-turing can communicate clearly and effi-ciently early in the program to reflect anymanufacturing constraints without com-promising designs," says Mark Phillips,Manufacturing Systems Supervisor, Paint

and Final Assembly Engineering."Assembly techniques now

can be developed at the same timecomponents are designed - bothon the computer simultaneously- reducing reliance on expensiveprototypes early in the product de-velopment process to assessmanufacturing feasibility. If youmake a design change later in theproduct development or toolingcycle, you put your timing at riskand you pay premium costs," saysBruce HettIe, Large/Luxury CarVehicle Center Manager, FordGlobal Final Assembly Engineer-

back for low running options - such asmanual windows," says Heithaus.

The 1997 model year build combina-tions equal 5600, compared to 312,000build combinations for previous models- and that drastic drop includes the addi-tion of four divisions, three powertrains,and right hand drive. "The real gainswe've achieved in productivity are theresult of manufacturing's early involve-ment in this program. The practice ofinvolVing manufacturing at the begin-ning of a program is not new. But what'sunique is how well the team used thisopportunity to allow engineering to un-derstand and experience manufacturing

to production - took eight months asopposed to the typical industry timeframe of three to four years. "The planthas a modular design. There is noassembly line. There are no conveyors,except in the paint oven area, in-volved in the 45 minute job cycle,"Szkodzinski says. EV1 is the first pro-duction vehicle to be made usingepoxy draw dies, and those dies wereup and running in 20 weeks, com-pared to the typical 45 to 48 weeks formetal dies.

Another General Motors exampleof data-driven engineering unfoldedduring planning sessions for the de-sign of five new minivan brands(Chevrolet Venture, Pontiac TransSport, Oldsmobile Silhouette, OpelSintra, and Vauxhall Sintra). The 1997minivans cover two wheelbases, fourengine families, two sliding doors, leftor right hand drives, and automatic ormanual transmissions - all from asingle platform at a single assemblyplant in Doraville, GA. "It's the com-plexity that drove a very earlymanufacturing presence," says RickHeithaus, Program ManufacturingManager.

The process began with engineeringand manufacturing representativescoming together in an area peppered GM's EV1 assembly.

with paper drawings of engineering re-leases. As the design process unfolded, thewall became a paper replica of the Doravilleassembly plant. "When you're not lookingat what's going on around a part, you couldmiss critical things. If an engineer doesn'tunderstand how a part will be built andassembled, the outcome can result in ergo-nomic and/or quality problems," explainsChuck Kingsley, Total Vehicle IntegrationEngineer. With engineering drawing re-leases being viewed early in the process bypurchasing, quality, production, and mate-rial departments as well as plant workers,the time-to-production table shrank.

"Engineers watched operators assemblecardboard mock-ups toseehow practi-cal or impractical the process was. Thiswas especially important in the trimarea because the process can be ana-lyzed before a mold is cut," explainsHeithaus. Give-and-take design exer-cises netted various simplified assem-bly methods. For instance, instead ofmultiple door plug harnesses, a singledoor plug serves a dual role. "Doorplugs come equipped with a high pen-etration option - such as power win-dows. The electrical lead comes to (anoperator) taped back. Itcanbebroughtforward for insertion when the optioncontent demands it, but remains taped Door plug assembly at GM's Doraville plant.

prototyping,Chryslerconsideredthou-sandsofcomputer-generateddesignitera-tions."Theinterfaceofengineeringandmanufacturingallowedustogetallthebugsoutoftheprocessintheverybegin-ning.Themanufacturingprocess,thecastingprocess,themachiningprocesswasoptimizedbeforethetoolingwasallbuilt,bought,andpaidfor.Sowebought

itonce,andweboughtitright.Wedidn'thavetogobackandkeepchangingthings,whichcostsmoney,"explainsBurkeBrown,Ex-ecutiveEngineerofLargeCarPlat-formPowertrainEngineering.

Morethan1000intakemanifolditerationsweredoneoncomputerbeforeaprototypewasbuilt.(NOTE:Previousengineprogramsviewedthreeorfourdesignitera-tions.)Computerfilesoftheintakemanifold'sdesignwerealsosenttothesupplieroftheplasticcompositepart."Thefilesgavethemaccesstotheprocess.Suppliersarepartofourextendedenterprise,andaccesstothatinformationallowsthemtode-velopaprocesssothattheycouldmanufacturethisthingandtakecostout,"Brownsays.Inanotherex-

ample,themeasurementprocessbeingusedintheplanttomanufacturethecylin-derheadisstoredinacomputerfile."It'salreadysetupinthecomputerinthebe-ginningofthedesignprocessaspartofoursimultaneousengineering.Priortobuild-ingourfirstprototypes,wereorganizedourworkingstructuretoanalyzeandde-signtheseenginessimultaneouslyasop-posedtoanalyzingat70%ofdesigncompletionasinthepast,"Brownsays.

"Downstreamdesignchangesonactualpartshavebeendramaticallyreduced.Nowforamanufacturingguythat'sadreamcometrue.Iteliminatestheold'designit,buildit,testit,breakit...designit,buildit,testit,breakit'cyclethatweusedtohaveinthisindustryforyears,"saysBruceCoventry,managerofEngineManufacturingEngineering.Pro-ductionofenginesbeginsinKenosha,WI,andTrenton,MI,inAugust.Theengineswillpowerthe1998DodgeIntrepid,ChryslerConcorde,ChryslerLHS,andEagleVision.

Thebestdesignstrategy-asexempli-fiedbyautomakers'evolvingpractices-involvesutilizingmanufacturinginput."Taketheextraefforttodoitrightthefirsttimeandwinthebattleformarketsharebydesigningforannihilationinthedesignroom,notonthemanufacturingfloor,"Munroadvises.

Munro&Associates,IncPhone:248-362-5110

Fax:248-362-5117WWW.ffiunroaSSOC.COffi

trainedonthedigitalbuck."It'simportanttogetthemtherighttrainingbecausesoft-warewillveryquicklyprovideyouthewrongsolutionsifit'snotusedproperly,"saysRichardRiff,ManagerCAD/CAM/CAE&PIMProjectOfficeAdvancedVe-hicleTechnology.Computersimulationsnoweliminateclaymodelsfromthecon-ceptual/stylingstageandthephysicalprototypesformerlyneededintheengi-neeringdesignstage,necessitatingphysi-calprototypesforthefinal/confirmationstage.Reducingthenumberofphysicalprototypeshashelpedcompressthede-velopmenttime(fromprogramapprovaltoproduction)from36monthsto24months.Thedigitalbuckanddigitalfac-toryarebeingutilizedtodevelopcritical

manufacturingprocessesforallFordcarsandtrucks,modelyear2000andbeyond.

ChryslerCorporationspentlessthan$625milliontode-velop(includingmanufactur-ingcosts)threenewaluminumV6engines.Theindustry'sfirstpaperless-designeden-gines(2.7-L,3.2-L,and3.5-L)shaved26weeksoffthedevel-opmenttime.(Projectapprovaltolaunchwas24months.)Andbyutilizinginputfrommanufacturing,CATIA-basedsoftwareforpredictivemodelingandrapid

changes.Wemadethosechangesearlyenoughthattherewerenoaddedcoststochangethedesign,buttherewouldhavebeensignificantcostsifthatchangewasmadelaterintheprocess.Inthisexample,werealizedtheneedforadesignchangebeforethefirstphysicalprototype,"notesHettle.

FullservicesupplierstoFordwillbe

FordMotorCo.'svirtualfactory.

vidualtrainingsessionswithdesigners/engineersondigitalbuckmethods.Thedigitalbuck/web-basedsiteprovidesus-ersatoolforevaluatingsystem-to-systeminterfaces."Fromacomputerworksta-tion,anengineercangraphicallypullto-gether-inafullvehicleenvironment-systeminterfacesbeforedoingaphysicalprototype.Thedigitalbuckallowsustoseeaspectslikeinterference/clear-ance,packagingandassemblyinrealtime,"explainsRayByrnes,DigitalBuckMethodsVehicleCAE/CAD/PIMIntegrationAdvancedVehicleTechnology.

Becausethecomputersimula-tionsreducethenumberofneededphysicalprototypes,Fordprojectssavingsofmorethan$200millionannually.Digitalbuckanddigitalfactoryconceptsareexpectedtore-duceby20%manufacturing-drivendesignchangesduringanewvehiclelaunch."Inthepast,productdesignengineerswoulddesignacompo-nent,aprototypepartwouldbemade,andthenmanufacturingengi-

Theoperator(left)explainstotheengineertheneersandhourlyproductspecialistsproblemsheexperiencesontheassemblylineofthewouldworktomaketheassemblyproduct.processfeasible.Makingengineer-ingchangesforeaseofassemblywasanexpensiveprospect.Nowengineeringchangescanbemadesooner,quicker,withtheinputofmanufacturingwhohastobuildthevehiclewithoutrelyingentirelyonexpensiveprototypes,"explainsPhillips.

Inthecomputer-simulatedfactory,assemblylinesworkers-ofvaryingsizes-completetheirtasks.Inoneex-ample,whenengineershadacomputer-generatedworkerassembleanewlyde-signeddoorsystem,thesimulationprovedthattwo-thirdsofthepopulationwouldnotbeabletocompletethetask."Weshowedthatasmallpersoncouldn'tefficientlyinstallthedesignconcept,andallinvolvedsawthatweneededdesign

The operator (left) explains to the engineer theproblems he experiences on the assembly line of theproduct.

vidual training sessions with designers/engineers on digital buck methods. Thedigital buck/web-based site provides us-ers a tool for evaluating system-to-systeminterfaces. "From a computer worksta-tion, an engineer can graphically pull to-gether - in a full vehicle environment -system interfaces before doing a physicalprototype. The digital buck allows us tosee aspects like interference/clear-ance, packaging and assembly inreal time," explains Ray Byrnes,Digital Buck Methods Vehicle CAE/CAD/PIM Integration AdvancedVelucle Technology.

Because the computer simula-tions reduce the number of neededphysical prototypes, Ford projectssavings of more than $200 mi..llionannually. Digital buck and digitalfactory concepts are expected to re-duce by 20% manufacturing-drivendesign changes during a new vehiclelaunch. "In the past, product designengineers would design a compo-nent, a prototype part would bemade, and then manufacturing engi-neers and hourly product specialistswould work to make the assemblyprocess feasible. Making engineer-ing changes for ease of assembly was anexpensive prospect. Now engineeringchanges canbe made sooner, quicker, withthe input of manufacturing who has tobuild the vehicle without relying entirelyon expensive prototypes," explainsPhillips.

In the computer-simulated factory,assembly lines workers - of varyingsizes - complete their tasks. In one ex-ample, when engineers had a computer-generated worker assemble a newly de-signed door system, the simulationproved that two-thirds of the populationwould not be able to complete the task."We showed that a small person couldn'tefficiently install the design concept, andall involved saw that we needed design

Ford Motor Co. 's virtual factory.

changes. We made those changes earlyenough that there were no added costs tochange the design, but there would havebeen significant costs if that change wasmade later in the process. In this example,we realized the need for a design changebefore the first physical prototype,"notes HettIe.

Full service suppliers to Ford will be

trained on the digital buck. "It's importantto get them the right training because soft-ware will very quickly provide you thewrong solutions if it's not used properly,"says Richard Riff, Manager CAD/CAM/CAE & PIM Project Office Advanced Ve-hicle Technology. Computer simulationsnow eliminate clay models from the con-ceptual/styling stage and the physicalprototypes formerly needed in the engi-neering design stage, necessitating physi-cal prototypes for the final! confirmationstage. Reducing the number of physicalprototypes has helped compress the de-velopment time (from program approvalto production) from 36 months to 24months. The digital buck and digital fac-tory are being utilized to develop critical

manufacturing processes forall Ford cars and trucks, modelyear 2000 and beyond.

Chrysler Corporation spentless than $625 million to de-velop (including manufactur-ing costs) three new alunUnumV6 engines. The industry'sfirst paperless-designed en-gines (2.7-L, 3.2-L, and 3.5-L)shaved 26 weeks off the devel-opment time. (Projectapproval to launch was 24months.) And by utilizinginput from manufacturing,CATIA-based software forpredictive modeling and rapid

prototyping, Chrysler considered thou-sands of computer-generated design itera-tions. "The interface of engineering andmanufacturing allowed us to get all thebugs out of the process in the very begin-ning. The manufacturing process, thecasting process, the machining processwas optimized before the tooling was allbuilt, bought, and paid for. So we bought

it once, and we bought it right. Wedidn't have to go back and keepchanging things, which costsmoney," explains Burke Brown, Ex-ecutive Engineer of Large Car Plat-form Powertrain Engineering.

More than 1000 intake manifolditerations were done on computerbefore a prototype was built.(NOTE: Previous engine programsviewed three or four design itera-tions.) Computer files of the intakemanifold's design were also sent tothe supplier of the plastic compositepart. "The files gave them access tothe process. Suppliers are part of ourextended enterprise, and access tothat information allows them to de-velop a process so that they couldmanufacture this thing and take costout," Brown says. In another ex-

ample, the measurement process beingused in the plant to manufacture the cylin-der head is stored in a computer file. "It'salready set up in the computer in the be-ginning of the design process as partofoursimultaneous engineering. Prior to build-ing our first prototypes, we reorganizedour working structure to analyze and de-sign these engines simultaneously as op-posed to analyzing at 70% of designcompletion as in the past," Brown says.

"Downstream design changes on actualparts have been dramatically reduced. Nowfor a manufacturingguy that's a dreamcometrue. It eliminates the old'design it, build it,testit, break it. ..designit, build it, test it, breakit' cycle that we used to have in this industryfor years," says Bruce Coventry, manager ofEngine Manufacturing Engineering. Pro-duction of engines begins in Kenosha, WI,andTrenton,MI,inAugust. Theengineswillpower the 1998 Dodge Intrepid, ChryslerConcorde, Chrysler LHS, and Eagle Vision.

The best design strategy - as exempli-fied by automakers' evolving practices -involves utilizing manufacturing input."Take the extra effort to do it right the firsttime and win the battle for market share bydesigning for annil1ilation in the designroom, not on the manufacturing floor,"Munro advises.

Munro & Associates, IncPhone: 248-362-5110

Fax: 248-362-5117www.munroassoc.com

Munro&

Associates,®

CHANGE AGENTS FORMANUFACTURING COMPETITIVENESS

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