Design is a team effort, but how do marketing andengineering talk to each otherl

The House of Quality

by JOHN R. HAUSER and DON CLAUSING

Digital Equipment, Hewlett-Packard, AT&T, andITT are getting started with it. Ford and General Mo-tors use i t -a t Ford alone there are more than 50 ap-plications. The "house of quality," the basic designtool of the management approach known as qualityfunction deployment (QFD), originated in 1972 atMitsubishi's Kobe shipyard site. Toyota and its sup-pliers then developed it in numerous ways. Thehouse of quality has been used successfully by Japa-nese manufacturers of consumer electronics, homeappliances, clothing, integrated circuits, syntheticrubber, construction equipment, and agriculturalengines. Japanese designers use it for services likeswimming schools and retail outlets and even forplanning apartment layouts.

A set of planning and communication routines,quality function deployment focuses and coordi-nates skills within an organization, first to design,then to manufacture and market goods that custom-

ers want to purchase and will continue to purchase.The foundation of the house of quality is the beliefthat products should be designed to reflect custom-ers' desires and tastes-so marketing people, designengineers, and manufacturing staff must workclosely together from the time a product is firstconceived.

The house of quality is a kind of conceptual mapthat provides the means for interfunctional planningand communications. People with different prob-

}ohn R. Hauser. at the Harvard Business School as a Mar-vin Bower fellow during the current academic year, isprofessor of management science at MIT's Sloan Schoolof Management. He is the author, with Glen L. Urban, ofDesign & Marketing of New Products (Prentice-Hall,1980}. Don Clausing is Bernard M. Gordon Adjunct Pro-fessor of Engineering Innovation and Practice at MIT.Previously he worked for Xerox Corporation. He intro-duced QFD to Ford and its supplier companies in 1984.

HARVARD BUSINESS REVIEW May-June 1988 63

HOUSE OF QUALITY

lems and responsibilities can thrash out designpriorities while referring to patterns of evidence onthe house's grid.

Whafs So Hard About Design

David Garvin points out that there are many di-mensions to what a consumer means by quality andthat it is a major challenge to design products thatsatisfy all of these at once.' Strategic quality manage-ment means more than avoiding repairs for consum-ers. It means that companies learn from customerexperience and reconcile what they want with whatengineers can reasonably build.

Before the industrial revolution, producers wereclose to their customers. Marketing, engineering, andmanufacturing were integrated - in the same individ-ual. If a knight wanted armor, he talked directly to thearmorer, who translated the knight's desires into aproduct. The two might discuss the material-platerather than chain armor-and details like fluted sur-faces for greater bending strength. Then the armorerwould design the production process. For strength-who knows why?-he cooled the steel plates in theurine of a black goat. As for a production plan, hearose with the cock's crow to light the forge fire sothat it would be hot enough by midday.

Today's fiefdoms are mainly inside corporations.Marketing people have their domain, engineerstheirs. Customer surveys will find their way ontodesigners' desks, and R&D plans reach manufactur-

EXHIBITI

Startup and preproduction casts at TayotaAuta Body befare and after QFD

April 1984Post QFD[39% ot pre QFD costs)

Preproduction costs

Startup costs

//: Lowrence P. Sullivan, "QuQlity Function Deploy-ment," Quality Progress. June 1986, p. 39. ff 1986 American Society forQuolity Control. Reprinted by permission

ing engineers. But usually, managerial functions re-main disconnected, producing a costly and demoral-izing environment in which product quality and thequality of the production process itself suffer.

Top executives are leaming that the use of inter-functional teams benefits design. But if top manage-ment could get marketing, designing, and manufac-turing executives to sit down together, what shouldtbese people talk about? How could they get theirmeeting off the ground? This is where the house ofquality comes in.

Consider the location of an emergency brake leverin one American sporty car. Placing it on the left be-tween the seat and the door solved an engineeringproblem. But it also guaranteed that women in skirts

EXHIBIT H

Japanese autamaker with QFD made fewerchanges than U.S. company without QFD

U.S. company

could not get in and out gracefully. Even if the systemwere to last a lifetime, would it satisfy customers?

In contrast, Toyota improved its rust prevention re-cord from one of the worst in tbe world to one of thebest by coordinating design and production decisionsto focus on this customer concern. Using the houseof quahty designers broke down "body durability"into 53 items covering everything from climate tomodes of operation. They obtained customer evalua-tions and ran experiments on nearly every detail ofproduction, from pump operation to temperaturecontrol and coating composition. Decisions on sheetmetal details, coating materials, and baking tempera-tures were all focused on those aspects of rust preven-tion most important to customers.

1. David A. Garvin, "Competing on the Eight Dimensions of Quality,"HBR Nnvcmbcr-December 1987, p. 101.

64 HARVARD BUSINESS REVIEW May-Junt 1988

Today, with marketing tech-niques so much more sophisti-cated than ever hef ore, companiescan measure, track, and comparecustomers' perceptions of prod-ucts with remarkable accuracy;all companies have opportunitiesto compete on quality And costscertainly justify an emphasis onquality design. By looking first atcustomer needs, then designingacross corporate functions, manu-facturers can reduce prelaunchtime and after-launch tinkering.

Exhibit I compares startup andpreproduction costs at ToyotaAuto Body in 1977, hefore QFD, tothose costs in 1984, when QFDwas well under way. House ofquality meetings early on reducedcosts hy more than 60%. Exhib-it II reinforces this evidence bycomparing the numher of designchanges at a Japanese auto manu-facturer using QFD with changes at a U.S. automak-er. The Japanese design was essentially frozen be-fore the first car came off the assembly line, whilethe U.S. company was still revamping months later.

EXHIBIT III

Customer attributes and bundles of CAsfora cardoor

PRIMARY MCONDABY nRTIASY

1 .

L

1

Oood opvratlon

anduM

• • i i

Good appaoranca

EASVTOOPENAND CLOSE DOOR

ISOLATION

ARMREST

INTERIOR TRIM

a-£AN

FIT

' Easy to close from outsideStays open on a hillEasy to open (rom outsideDoesn't kici< backEasy to close trom insideEasy to open from inside

Doesn't leok in rainNo rood noiseDoesn't leak in cor washNo wind noiseDoesn't drip water or snow when openDoesn't rattle

Soft, comfortableIn right position

Materiol won't fadeAttractive (nonplostic iook]

Easy to cieanNo grease trom door

Uniform gaps between matching panels

Building the House

There is nothing mysterious about the house ofquality. There is nothing particularly difficult aboutit either, but it does require some effort to get used toits conventions. Eventually one's eye can bounceknowingly around the house as it would over a road-map or a navigation chart. We have seen some appli-cations that started with more than 100 customerrequirements and more than 130 engineering consid-erations. A fraction of one subchart, in this case forthe door of an automohile, illustrates the house's ba-sic concept well. We've reproduced this subchart por-tion in the illustration "House of Quality," and we'lldiscuss each section step-hy-step.

What do customers wanti The house of quality be-gins with the customer, whose requirements arecalled customer attributes (CAs)-phrases customersuse to descrihe products and product characteristics(see Exhibit ///). We've listed a few here; a typical ap-plication would have 30 to 100 CAs. A car door is"easy to close" or "stays open on a hill"; "doesn't leakin rain" or allows "no (or little) road noise." Some

Japanese companies simply place their products inpuhlic areas and encourage potential customers toexamine them, while design team members listenand note what people say Usually, however, more for-mal market research is called for, via focus groups, in-depth qualitative interviews, and other techniques.

CAs are often grouped into bundles of attributesthat represent an overall customer concern, like"open-close" or "isolation." The Toyota rust-preven-tion study used eight levels of bundles to get fromthe total car down to the car body Usually the proj-ect team groups CAs by consensus, hut some com-panies are experimenting with state-of-the-art re-search techniques that derive groupings directlyfrom customers' responses (and thus avoid argu-ments in team meetings).

CAs are generally reproduced in the customers'own words. Experienced users of the house of qualitytry to preserve customers' phrases and even cliches-knowing that they will be translated simultaneouslyby product planners, design engineers, manufactur-ing engineers, and salespeople. Of course, this raisesthe problem of interpretation: What does a customerreally mean hy "quiet" or "easy"? Still, designers'words and inferences may correspond even less tocustomers' actual views and can therefore misleadteams into tackling problems customers considerunimportant.

Not all customers are end users, by the way CAscan include the demands of regulators ("safe in a sidecollision"), the needs of retailers ("easy to display"),

HARVARD BUSINESS REVIEW May-|unc 1988 65

HOUSE OF QUALITY

EXHIBIT IV

Relative-importance weights Of customerattributes

BUNDLES CUSTOMER ATTRIBUTES

EASY TO OPEN Easy to close from outsideAND CLOSE DOOR Etavs open on • hill

RELATIVEIMPORTANCE

75

ISOLATION Doesn't leak In tolnNo road noise

A complete list totals 100%

the requirements of vendors ("satisfy assembly andservice organizations"), and so forth.

Are all preferences equally important^ Imagine agood door, one that is easy to close and has powerwindows that operate quickly There is a problem,however. Rapid operation calls for a bigger motor,which makes the door heavier and, possibly harder toclose. Sometimes a creative solution can be foundthat satisfies all needs. Usually however, designershave to trade off one benefit against another.

To bring the customer's voice to such delibera-tions, house of quality measures the relative impor-tance to the customer of all CAs. Weightings arebased on team members' direct experience with cus-tomers or on surveys. Some innovative businessesare using statistical techniques that allow customersto state their preferences with respect to existing andhypothetical products. Other companies use "re-vealed preference techniques," which judge con-sumer tastes by their actions as well as by theirwords-an approach that is more expensive and diffi-cult to perform but yields more accurate answers.(Consumers say that avoiding sugar in cereals is im-portant, but do their actions reflect their claims?)

Weightings are displayed in the house next to eachCA-usually in terms of percentages, a complete listtotahng 100% (see Exhibit IV).

Will delivering perceived needs yield a competi-tive advantage! Companies that want to match orexceed their competition must first know wherethey stand relative to it. So on the right side of thehouse, opposite the CAs, we list customer evalua-tions of competitive cars matched to "our own" (seeExhibit V].

Ideally, these evaluations are based on scientificsurveys of customers. If various customer segments

evaluate products differently-luxury vs. economycar buyers, for example-product-planning teammembers get assessments for each segment.

Comparison with the competition, of course, canidentify opportunities for improvement. Take our cardoor, for example. With respect to "stays open on ahill," every car is weak, so we could gain an advantagehere. But if we looked at "no road noise" for the sameautomobiles, we would see that we already have anadvantage, which is important to maintain.

Marketing professionals will recognize the right-hand side of Exhibit V as a "perceptual map." Percep-tual maps based on bundles of CAs are often used toidentify strategic positioning of a product or productline. This section of the house of quality provides anatural link from product concept to a company'sstrategic vision.

How can we change the product The marketingdomain tells us what to do, the engineering domaintells us how to do it. Now we need to describe theproduct in the language of the engineer. Along the topof the house of quality the design team lists those en-gineering characteristics (ECs) that are likely to af-fect one or more of the customer attributes (seeExhibit VI]. The negative sign on "energy to closedoor" means engineers hope to reduce the energy re-quired. If a standard engineering characteristic affectsno CA, it may be redundant to the EC list on thehouse, or the team may have missed a customerattribute. A CA unaffected by any EC, on the otherhand, presents opportunities to expand a car's physi-cal properties.

Any EC may affect more than one CA. The resis-tance of the door seal affects three of the four cus-tomer attributes shown in Exhibit W-and othersshown later.

Engineering characteristics should describe theproduct in measurable terms and should directly af-fect customer perceptions. The weight of the doorwill be felt by the customer and is therefore a rele-vant EC. By contrast, the thickness of the sheet metalis a part characteristic that the customer is unlikelyto perceive directly It affects customers only by in-fluencing the weight of the door and other engineer-ing characteristics, like "resistance to deformation ina crash."

In many Japanese projects, the interfunctionalteam begins with the CAs and generates measurablecharacteristics for each, like foot-pounds of energyrequired to close the door. Teams should avoid ambi-guity in interpretation of ECs or hasty justification ofcurrent quality control measurement practices. Thisis a time for systematic, patient analysis of each char-acteristic, for brainstorming. Vagueness will eventu-

HARVARD BUSINESS REVIEW May-[iini: 1988

EXHIBIT Vally yield indifference to thingscustotners need. Characteristicsthat are trivial will make theteam lose sight of the overall de-sign and stifle creativity.

How much do engineers influ-ence customer-perceived quali-tiesl The interfunctional teamnow fills in the body of the house,the "relationship matrix," indi-cating how much each engineer-ing characteristic affects eachcustomer attribute. The teamseeks consensus on these evalu-ations, basing them on expert en-gineering experience, customerresponses, and tabulated datafrom statistical studies or controlled experiments.

The te<im uses numhers or symbols to establishthe strength of these relationships (see Exhibit VII).Any symbols will do; the idea is to choose those thatwork best. Some teams use red symbols for relation-ships hased on experiments and statistics and pencilmarks for relationships based on judgment or intui-tion. Others use numbers from statistical studies. Inour house, we use check marks for positive andcrosses for negative relationships.

Once the team has identified the voice of the cus-tomer and linked it to engineering characteristics, itadds objective measures at the bottom of the housebeneath the ECs to which they pertain (see ExhibitVIII). When objective measures are known, the teamcan eventually move to establish target values-idealnew measures for each EC in a redesigned product.If the team did its homework when it first identi-fied the ECs, tests to measure benchmark valuesshould he easy to complete. Engineers determinethe relevant units of measurement-foot-pounds,decihels, etc.

Incidentally, if customer evaluations of CAs donot correspond to objective measures of related ECs-if, for example, the door requiring the least ener-gy to open is perceived as "hardest to open"-thenperhaps the measures are faulty or the car is sufferingfrom an image problem that is skewing consumerperceptions.

How does one engineering change affect othercharactehstical An engineer's change of the gear ra-tio on a car window may make the window motorsmaller but the window go up more slowly And if theengineer enlarges or strengthens the mechanism, thedoor prohably will he heavier, harder to open, or maybe less prone to remain open on a slope. Of course.

Customers' evaluations at competitiveproducts

CUSTOMER ATTDIBUTES

RELATIVE

IMPORTANCE OUSTOMER PERCEPTIONS

1 2 3 4 5

EASY TO OPENAND CLOSEDOOi5

ISOLATION

Easv to close from outside

Stays open on a hill

Doesn't \so^ in rain

No rood noise

7

5

3

2

OUR CAR DOOR

COMPETITOR AS

COMPETITOR BS

there might he an entirely new mechanism that im-proves all relevant CAs. Engineering is creative solu-tions and a balancing of objectives.

The house of quality's distinctive roof matrix helpsengineers specify the various engineering featuresthat have to be improved collaterally (see Exhibit IX).To improve the window motor, you may have to im-prove the hinges, weather stripping, and a range ofother ECs.

Sometimes one targeted feature impairs so manyothers that the team decides to leave it alone. Theroof matrix also facilitates necessary engineeringtrade-offs. The foot-pounds of energy needed to closethe door, for example, are shown in negative relationto "door seal resistance" and "road noise reduction."In many ways, the roof contains the most criticalinformation for engineers because they use it to bal-ance the trade-offs when addressing customerbenefits.

Incidentally we have been talking so far about thebasics, but design teams often want to ruminate onother itif ormation. In other words, they custom-buildtheir houses. To the column of CAs, teams may addother columns for histories of customer complaints.To the ECs, a team may add the costs of servicingthese complaints. Some applications add data fromthe sales force to the CA list to represent strategicmarketing decisions. Or engineers may add a rowthat indicates the degree of technical difficulty,showing in their own terms how hard or easy it is tomake a change.

Some users of the house impute relative weightsto the engineering characteristics. They'll estahlishthat the energy needed to close the door is rough-ly twice as important to consider as, say, "checkforce on 10° slope." By comparing weighted charac-teristics to actual component costs, creative design

HARVARD BUSINESS REVIEW Maylunc 198S 67

HOUSE OF QUALITY

teams set priorities for improving components. Suchinformation is particularly important when costcutting is a goal. {Exhibit X includes rows for tech-nical difficulty, imputed importance of ECs, and esti-mated costs.)

There are no hard-and-fast rules. The symbols,lines, and configurations that work for the particularteam are the ones it should use.

Using the House

How does the house lead to the bottom line? Thereis no cookbook procedure, but the house helps theteam to set targets, which are, in fact, entered on the

bottom line of the house. Eor engineers it is a way tosummarize basic data in usable form. For marketingexecutives it represents the customer's voice. Gen-eral managers use it to discover strategic opportuni-ties. Indeed, the house encourages all of these groupsto work together to understand one another's priori-ties and goals.

The house relieves no one of the responsibility ofmaking tough decisions. It does provide the meansfor all participants to debate priorities.

Let's run through a couple of hypothetical situa-tions to see how a design team uses the house.• Look at Exhibit X. Notice that our doors are muchmore difficult to close from the outside than those oncompetitors' cars. We decide to look further becauseour marketing data say this customer attribute is

EXHIBIT VI

Engineering characteristics tell how tochange the product

nU

0

at

ive

o&

t

AJ

O ^ESStt t-

o <m O

CUSTOMER ^ O N VAnRIBUTES \ . ^ N ^

OP

EN

ED

OO

REA

SY T

OA

ND

CLO

S

0

LAT

Ut o

Easy to close from outside

Stays open on a hill

Doesn't leak ih rain

No road noise

•

7

5

3

2

OnX)

ose

oo

Ene

rg

OPEN-CLOSE

O

m

(Dco

a>o

Che

c^

-1-

EFFORT

a

O

coCD

Che

ch

-1-

• • • • • • • • •

r

sist

aea

l

ooQ

+

SEALING-INSULATION

on

o

edu

CD

lois

Roa

d

4-

. . . a . . . . .

Customer perceptions

1 2 3 4 5

tJI^ L -̂i 1

iJW—^ ^ .

1 \ P^—L-ll

-OUR CAR

-A'S CAR

-B'S CAR

68HARVARD BUSINESS REVIEW May-|une 1988

EXHIBIT VII

Relationship matrix shows how engineering decisionsaffect customer perceptions

(A

oZ ot— UJtt I-

O<<

CUSTOMERAHRIBUTES

Q:

5;OO (/)

- 9

<

O

d

Easy fo close from outside

Stays open on a hill

Doesn't leak in rain

No road noise

OPEN-CLOSEEFFORT

5EALING-INSULATION

Relationships

Strong positive

Medium positive

Medium negative

Strong negative

Customer perceptions

1 2 3 4 5

AS CAR

B'S CAR

important. From the central matrix, the hody ofthe house, we identify the ECs that affect this cus-tomer attribute: energy to close door, peak closingforce, and door seal resistance. Our engineers judgethe energy to close the door and the peak closingforce as good candidates for improvement togetherbecause they are strongly, positively related to theconsumer's desire to close the door easily. They de-termine to consider all the engineering ramifica-tions of door closing.

Next, in the roof of the house, we identify whichother ECs might he affected hy changing the doorclosing energy. Door opening energy and peak closing

force are positively related, but other ECs (checkforce on level ground, door seals, window acoustictransmission, road noise reduction) are bound to hechanged in the process and are negatively related. It isnot an easy decision. But with objective measures ofcompetitors' doors, customer perceptions, and con-sidering information on cost and technical difficul-ty, we - marketing people, engineers, and top manag-ers-decide that the benefits outweigh the costs. Anew door closing target is set for our door-7.5 foot-pounds of energy. This target, noted on the very bot-tom of the house directly below the relevant EC, es-tahlishes the goal to have the door "easiest to close."

HARVARD BUSINESS REVIEW May-Iuni: 1988 69

HOUSE OF QUALITY

Look now at the customer attribute "no roadtioise" and its relationship to the acoustic transmis-sion of the window. The "road noise" CA is onlymildly important to customers, and its relationshipto the specifications of the window is not strong.Window design will help only so much to keepthings quiet. Decreasing the acoustic transmissionusually makes the window heavier. Examining theroof of the house, we see that more weight wouldhave a negative impact on ECs (open-close energy,cheek forces, etc.) that, in turn, are strongly related toCAs that are more important to the customer thanquiet ("easy to close/' "stays open on a hill"). Finally,

marketing data show that we already do well on roadnoise; customers perceive our car as hetter thancompetitors'.

In this case, the team decides not to tamper withthe window's transmission of sound. Our target staysequal to our current acoustic values.

In setting targets, it is worth noting that the teamshould emphasize customer-satisfaction values andnot emphasize tolerances. Do not specify "hetween 6and 8 foot-pounds," but rather say, "7.5 foot-pounds."This may seem a small matter, but it is important.The rhetoric of tolerances encourages drift towardthe least costly end of the specification limit and

EXHiBiTVlii

Objective measures evaluate competitiveproducts

CUSTOAnRiBI

EA

SY

TO

OP

EN

AN

D C

LOS

E D

OO

RIS

OLA

TIO

NO

bje

ctiv

em

easu

res

1 1

n

MERJTES

/ R

eiat

ive im

po

rtan

ce

/E

NG

INE

ER

iNG

Easy to close from outside

Stays open on a hill

Doesn't leak in rain

No road noise

s

n

>tu>

tE

i

s7

5

3

2

Measurement units

Our cor door

As car door

B'S car door

OPEN-CLOSEEFFORT

- E

nerg

y to

clo

se d

oor

•

f-lb

11

9

9,5

-f- C

heck

fo

rce

on leve

l gro

und

•

Ib

12

12

11

+ C

heck

fo

rce

on

10"

slo

pe

•

ib

6

6

7

SEALING-INSULATION

+ D

oor

seal

resi

stan

ce

X

•

b/tt

3

2

2

+

Roa

d n

oise

reduct

ion

•

db

9

5

6

Reiationships

^ Strong positive

sf Medium positive

X Medium negative

X Strong negative

Customer perceptions

1 2 3 4 5

^k nui? CAP

^ AS CAR

B'S CAR

70 HARVARD BUSINESS REVIEW May-June 1988

IXHIBITIX

Roof mafrix facilifafes engineeringcreativity

nq

o ^Z tt— lutt I-uj OZ<± ttO <w O

CUSTOMERAnRIBUTES

a. QO m0 </>

- 9o<_

dCO

.2.0

O E

Easy to close from outside

Stays open on a hill

Doesn't leak in rain

No road noise

Measurement uivh

Our car door

As car door

B'S car door

OPEN-CLOSEEFFORT

ttti

11

95

12

12

Ib

SEALING-INSULATION

Ibi

V

db

Relationships

*r Strong positive

V Medium positive

X Medium negative

X strong negative

Customer perceptions

1 2 3 4 5

-OUR CAR

-A'S CAR

-B'S CAR

does not reward designs and components whoseengineering values closely attain a specific cus-tomer-satisfaction target.

The Houses Beyond

The principles underlying the house of quality ap-ply to any effort to establish clear relations betweenmanufacturing functions and customer satisfactionthat are not easy to visualize. Suppose that our team

decides that doors closing easily is a critical attri-bute and that a relevant engineering characteristicis closing energy. Setting a target value for closingenergy gives us a goal, but it does not give us a door.To get a door, we need the right parts (frame, sheetmetal, weather stripping, hinges, etc.), the right pro-cesses to manufacture the parts and assemble theproduct, and the right production plan to get it built.

If our team is truly interfunctional, we can even-tually take the "hows" from our house of qualityand make them the "whats" of another house, onemainly concerned with detailed product design. En-

HARVARD BUSINESS REVIEW May-|une 1988 71

EXHIBIT X

House Of quality

CUSTOAnpiBi

EASY

TO

OP

EN

AN

D C

LOS

E D

OO

RIS

OLA

TIO

NO

bje

ctiv

enn

easu

res

1 1—

MERJTES

/ R

eiat

ive

Im

po

rtan

ce

|

/̂F

E

NG

INE

ER

ING

Easy to close from outside

Stays open on a hill

Easy to open trom outside

Doesn't kick back

:

Doesn't leak in rain

No road noise

•

0>itu

tIt

N7

5

3

3

3

2

Measurement units

Our car door

As car door

B's car door

Technicai difficulty

imputed importance (%)(all total 100%)

Estimated cost (%)(all total 100%)

Targets

OPEN-CLOSEEFFORT

- E

nerg

y to

clo

se

door

•

tt-lb

11

9

9.5

4

10

5

75ftIb

+

Check

fo

rce

on

leve

l gro

und

•

Ib

12

12

11

5

6

2

9Ib

+

Check

fo

rce

on

10°

slo

pe

•

to

6

6

7

1

4

2

6to

- E

nerg

y to

open

door

••

ft-ib

10

9

11

1

9

9

7.5fib

- P

eak

closi

ng

fo

rce

•

Ib

18

13

14

3

1

5

12Ib

. . .

SEALING-INSULATiON

+

Doo

r se

al

resi

stan

ce

•

b/ft

3

2

2

I

6

6

3b/ff

+ A

cous

tic t

rans

mis

sion

, w

indow

-

.10

.10

.10

3

2

6

.10

+

Roa

d n

ois

e re

duct

ion

•

at:)

9

5

6

3

4

9

9db

+

Wat

er r

esis

tanc

e

•

psi

70

60

60

5

3

2

70psi

Reiationships

w Strong positive

Medium positive

Medium negative

X Strong negative

Customer perceptions

1 2 3 4 5

72 HARVARD BUSINESS REVIEW Maylune 1988

HOUSE OF QUALITY

EXHIBIT XI

Linked houses convey the customer's voice through to manutacturing

Par

tsics

1st

acte

r

0

u

Key processoperations

I I I

HOUSEOF QUAUTY

MRTSDEPU3YMENT

PROCESSPLANNING

PRODUCTIONPLANNING

Source. Modified Iromafigure supplied by the American Supplier Institute, Inc., Dearborn, Uichigan,

gineering characteristics like foot-pounds of closingenergy can become the rows in a parts deploymenthouse, while parts characteristics- like hinge proper-ties or the thickness of the weather stripping-hecome the columns (see Exhibit XI].

This process continues to a third and fourth phaseas the "hows" of one stage become the "whats" of thenext. Weather-stripping thickness-a "how" in theparts house-becomes a "what" in a process plan-ning house. Important process operations, like "rpmof the extruder producing the weather stripping" be-come the "hows." In the last phase, production plan-ning, the key process operations, like "rpm of theextruder," become the "whats," and production re-quirements-knob controls, operator training, main-tenance-become the "hows."

These four linked houses imphcitly convey thevoice of the customer through to manufacturing. Acontrol knob setting of 3.6 gives an extruder speed of

100 rpm; this helps give a reproducible diameter forthe weather-stripping bulb, which gives good sealingwithout excessive door-closing force. This featureaims to satisfy the customer's need for a dry, quiet carwith an easy-to-close door.

None of this is simple. An elegant idea ultimatelydecays into process, and processes will be confound-ing as long as human beings are involved. But that isno excuse to hold back. If a technique like house ofquality can help break down functional barriers andencourage teamwork, serious efforts to implement itwill be many times rewarded.

What is also not simple is developing an organiza-tion capable of absorbing elegant ideas. The principalbenefit of the house of quality is quality in-house. Itgets people thinking in the right directions andthinking together. For most U.S. companies, thisalone amounts to a quiet revolution. ^Reprint 88307

HARVARD BUSINESS REVIEW May-|une 1988 73