Nueva Filosofia de Construccion1

8/17/2019 Nueva Filosofia de Construccion1

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CIFECENTER FOR INTEGRATED FACILITY ENGINEERING

APPLICATION OF

THE NEW PRODUCTION PHILOSOPHY

TO CONSTRUCTION

By

Lauri Koskela

CIFE Technical Report #!

Septe"er$ %&&!


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STANFORD UNI'ERSITY


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Copyright © 1992 by

Lauri Koskela

If you would like to contact the author please write to:

VTT Building Technology

P.O. Box 1801

FIN-02044 VTT

Finland

e-mail addre! lauri."o"ela#$%%.&i


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Summary: TECHNICAL REPORT #72

Title: Application of te Ne! Pro"uction Piloopy to Contruction

Autor: Lauri Koskela

V !uilding echnology

"#$# !o% 1&'1(I)*'2'++ V

(inland

e*,ail: lauri#koskela-.tt#fi

$ate: /ugust0 1992

%un"in&: he study has been realied during the stay of the author as a Visiting

cholar

at CI(3# (unded by echnical 4esearch Centre of (inland0 the (ederation of

the (innish !uilding Industry and the 5ihuri (oundation#

A'tract: he background and de.elop,ent of the new production philosophy are

presented# he conceptual basis of the traditional and the new production

philosophies0 as applied in ,anufacturing0 are e%a,ined# he traditionalconceptual basis of construction is criticied0 and an initial new interpretation of

construction is gi.en based on the new philosophy# (inally0 the challenges of i,ple,enting the new production philosophy in construction are considered#

Su'(ect: he ter, 6new production philosophy7 refers to an e.ol.ing set of

,ethodologies0 techni8ues and tools0 the genesis of which was in the apanese

I and C efforts in car ,anufacturing# e.eral alternati.e na,es are presently used to refer to this philosophy: lean production0 I;C0 world class

,anufacturing0 ti,e based co,petition# In ,anufacturing0 great gains in

perfor,ance ha.e been realied by this new production philosophy# 5ith thee%ception of 8uality ,ethodologies0 this new philosophy is little known in

construction#

O'(ecti)e*+enefit: he goal of this report is to assess whether or not the new

production philosophy has i,plications for construction#

,eto"olo&y: he study consisted ,ainly of a literature re.iew and a conceptual

analysis and synthesis# In the last stage of the study0 four engineering or

construction co,panies were .isited to ascertain the present le.el of

i,ple,entation of the new philosophy#

Reult: Construction should adopt the new production philosophy# In ,anufacturing0 the new

production philosophy i,pro.es co,petiti.eness by identifying and eli,inating waste

= or other control tools# Construction has traditionally

tried to i,pro.e co,petiti.eness by ,aking con.ersions incre,entally ,ore efficient#

!ut ?udging fro, the ,anufacturing e%perience0 construction could realie dra,atic

i,pro.e,ents si,ply by identifying and eli,inating non con.ersion


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processes# /s de,onstrated pre.iously by the ,anufacturing industry@s e%perience0

adoption of the new production philosophy


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will be a funda,ental paradig, shift for the construction industry# he i,plications of

this for design is that the process of construction ,ust be de.eloped in con?unction withthe design itself#

/n initial set of design and i,pro.e,ent principles for flow processes is

presented that can ser.e as an i,ple,entation guideline#

>a?or de.elop,ent efforts in construction0 like industrialiation0 co,puter

integrated construction and construction auto,ation ha.e to be redefined to

acknowledge the need to balance flow i,pro.e,ent and con.ersion

i,pro.e,ent#

he conceptual foundation of construction ,anage,ent and engineering0 being

based on the concept of con.ersion only0 is obsolete# (or,aliation of the

scientific foundations of construction ,anage,ent and engineering should be a

pri,ary long ter, task for research#

Reearc tatu: his e%ploratory study raises a series of research 8uestions# o,e of the, are currently addressed in other ongoing CI(3 pro?ects# (or e%a,ple0 the

relation between process i,pro.e,ent and technical integration is assessed in

the study on integration@s i,pact on plant 8uality# $ther 8uestions will beaddressed in future CI(3 pro?ects#

he author will continue this line of research at the echnical 4esearch Centre

of (inland0 focusing on proble,s of i,ple,entation#


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TA+LE O% CONTENTS

3%ecuti.e su,,ary 2

/cknowledge,ents A

1# Introduction +2# )ew production philosophy: origin0 de.elop,ent and ,ain ideas B

2#1 $rigins and diffusion B2#2 >ain ideas and techni8ues B2#A Conceptual e.olution &2#+ !enefits 9

A# )ew production philosophy: conceptual basis 11A#1 5hat is a production philosophy 11A#2 Conceptual basis of the con.entional production philosophy 12A#A Conceptual basis of the new production philosophy 1BA#+ "rinciples for flow process design and i,pro.e,ent 1D

A#B Continuous i,pro.e,ent .s# inno.ation 2+A#E >easure,ents in continuous i,pro.e,ent 2EA#D I,ple,entation of the new philosophy 2DA#& Conclusions 2&

+# Construction as acti.ity A'+#1 he traditional conceptualiation of construction A'+#2 (low proble,s caused by con.entional ,anagerial concepts A1+#A 5aste and .alue loss in construction A++#+ Fetri,ental i,pact on de.elop,ent efforts AE+#B Conclusions AD

B# Construction as flow A&B#1 (low processes in construction A&

B#2 >easures for construction +1

$.erco,ing flow proble,s caused by con.entional ,anagerial

concepts

$.erco,ing flow proble,s caused by the peculiarities ofconstruction ++

B#B Conclusions B'E# I,ple,entation of the new production philosophy in construction B1

E#1 "resent status of i,ple,entation: e%periences and barriers B1

I,ple,entation of process i,pro.e,ent by engineering andconstruction organiations BE

E#A 4edefining ,a?or de.elop,ent efforts in construction BD

E#+ 4esearch and education in construction E2E#B Conclusions E+

D# u,,ary EB

!ibliography E&


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1


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E-EC.TI/E S.,,AR0

In ,anufacturing0 great gains in perfor,ance ha.e been realied by a new production

philosophy# In construction0 this new philosophy is little known#

he con.entional thinking .iews production as con.ersion processes# he new

philosophy .iews production as consisting of both con.ersions and flows# $nly

con.ersions add .alue# his has funda,ental i,plications for design0 control and

i,pro.e,ent of production processes#

he i,pro.e,ent of flow acti.ities should pri,arily be focused on reducing or

eli,inating the,0 whereas con.ersion acti.ities ha.e to be ,ade ,ore efficient# /n

initial set of design and i,pro.e,ent principles for flow processes has e.ol.ed#

In construction0 conceptualiation of production is based on the con.ersion process

,odel0 as for,erly in ,anufacturing#

/ccording to the new .iew0 a construction pro?ect consists of three basic flows


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2


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AC1NOLE$3E,ENTS

his research was ,ade possible through grants fro, the echnical 4esearch Centre of (inland0 the (ederation of the (innish !uilding Industry and the 5ihuri (oundation#

he Center for Integrated (acility 3ngineering #5# Kellogg Co,pany#

he ideas of the report0 in their .arious stages0 were co,,ented upon by se.eral faculty

,e,bers and students in the Fepart,ent of Ci.il 3ngineering and the Center for

Integrated (acility 3ngineering at tanford Hni.ersity# Valuable feedback was alsogi.en by construction faculty ,e,bers of HC !erkeley#


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A


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4 Intro"uction

he proble,s of construction are well*known# Construction producti.ity lags that of

,anufacturing# $ccupational safety is notoriously worse than in other industries# Fue to

inferior working conditions0 there are work force shortages in ,any countries@

construction sector# he 8uality of construction is considered to be insufficient#

/ nu,ber of solutions or .isions ha.e been offered to relie.e the chronic proble,s in

construction# Industrialiation anufacturing has been a reference point and a source of inno.ations in construction

for ,any decades# (or e%a,ple0 the idea of industrialiation co,es directly fro,

,anufacturing# Co,puter integration and auto,ation also ha.e their origin in,anufacturing0 where their i,ple,entation is well ahead co,pared to construction#

)ow0 there is another de.elop,ent trend in ,anufacturing0 the i,pact of which appears

to be ,uch greater than that of infor,ation and auto,ation technology# his trend0which is based on a new production philosophy0 rather than on new technology0 stresses

the i,portance of basic theories and principles related to production processes#

Gowe.er0 because it has been de.eloped by practitioners in a process of trial and error0the nature of this approach as a philosophy escaped the attention of both professional

and acade,ic circles until the end of 19&'@s#

In construction0 there has been rather little interest in this new production philosophy#

he goal of this report is to assess whether or not the new production philosophy has

i,plications for construction#

he study on which this report is based consisted ,ainly of a literature re.iew and a

conceptual analysis and synthesis# In the last stage of the study0 four co,panies were

.isited to ascertain the present le.el of i,ple,entation of the new approach# (indings

fro, co,panies are presented as anecdotal e.idence in support of argu,entation#

he structure of the report is as follows# In Chapter 20 the background and de.elop,entof the new production philosophy are presented# In Chapter A0 the conceptual basis of

the traditional and the new production philosophies0 as applied in ,anufacturing0 are

e%a,ined# Chapter + analyes and criti8ues the traditional conceptual basis of construction# /n interpretation of construction based on the new philosophy is gi.en in

Chapter B# )e%t0 the i,ple,entation of the new production philosophy in construction

is considered in Chapter E# (inally0 Chapter D contains a short su,,ary of the report#


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+


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2 Ne! pro"uction piloopy: ori&in5 "e)elopment5

an" main i"ea

Ori&in an" "iffuion

he ideas of the new production philosophy first originated in apan in the 19B'@s# he,ost pro,inent application was the oyota production syste,# he basic idea in the

oyota production syste, is the eli,ination of in.entories and other waste through

s,all lot production0 reduced set*up ti,es0 se,iautono,ous ,achines0 co*operationwith suppliers0 and other techni8ues onden 19&A0 $hno 19&&0 hingo 19&+0 hingo

19&&=#

i,ultaneously0 8uality issues were attended to by apanese industry under the

guidance of /,erican consultants like Fe,ing0 uran and (eigenbau,# uality

philosophy e.ol.ed fro, a statistical ,ethod of 8uality assurance to a wider approach0

including 8uality circles and other tools for co,pany*wide de.elop,ent#

hese ideas were de.eloped and refined by industrial engineers in a long process of trialand errorJ establish,ent of theoretical background and wider presentation of the

approach was not seen as necessary# Conse8uently0 up to the beginning of the 19&'@s0

infor,ation and understanding of the new approach in the 5est was li,ited# Gowe.er0

the ideas diffused to 3urope and /,erica starting in about 19DB0 especially in theauto,obile industry#

Furing the 19&'@s0 a wa.e of books were published which analyed and e%plained the

approach in ,ore detail


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e.olution# )ew

1 he first scholarly paper in 3nglish was published in 19DD


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B


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concepts e,erge and the content of old concepts change# he sa,e concept is used to

refer to a pheno,enon on se.eral le.els of abstraction# It is not clear where to place the boundaries between related concepts#

5e ha.e chosen to base this o.er.iew on two historically i,portant 6root7 ter,s0 ust

In i,e


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4elations diagra,0 affinity diagra,0 tree diagra,0 ,atri% diagra,0 ,atri% data*analysis diagra,0 process decision

progra, chart0 arrow diagra,#


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E


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22= Relate" concept

>any new concepts ha.e surfaced fro, I and C efforts# hese ha.e been rapidly

elaborated and e%tended0 starting a life of their own# e.eral of these concepts are

described below#

Total Pro"ucti)e ,aintenance 9TP,

otal producti.e ,aintenance refers to autono,ous ,aintenance of production

,achinery by s,all groups of ,ulti*skilled operators 0 the oyota production syste, could not function#

Employee in)ol)ement

here are se.eral reasons for e,ployee in.ol.e,ent


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D


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Concurrent en&ineerin&

Concurrent anufacturability#

/alue 'ae" trate&y 9or mana&ement

Value based strategy refers to 6conceptualied and clearly articulated .alue as the basis

for co,peting7


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the new


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&


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philosophy began and was diffused without any scientific0 for,alied basis: factory

.isits0 case descriptions and consultants ha.e been the ,eans of technology transfer#

he conception of the new production philosophy as a general ,anage,ent philosophy

was first pro,oted by Fe,ing


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9


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Ta'le 1. (e&ini%ion o& %he ne) *roduc%ion *hiloo*hy.

3oal of te Toyota pro"uction ytem according to >onden


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1'


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; Ne! pro"uction piloopy: conceptual 'ai

/ basic tenet of this report is that lack of theoretical understanding has greatly

ha,pered the diffusion of the new production philosophy to industries which do not

ha.e ,any si,ilarities with car production# /n e%plicit0 preferably for,alied

theoretical basis is necessary for transfer of the new philosophy to new settings and for effecti.e education#

In the following0 we first define a production philosophy and then proceed to analyethe traditional production philosophy# /fter obser.ing certain flaws in the traditional

conceptual basis0 the essential ele,ents of the new production philosophy are

presented# / nu,ber of design and i,pro.e,ent principles0 i,plicit in the .arious practical approaches of the new production philosophy0 are e%a,ined# (inally0 other

i,portant i,plications of the new philosophy are considered#

at i a pro"uction piloopy

he answer to the abo.e 8uestion is not self*e.ident# /s !loch argues0 this lack of

definition ,ay be associated with the fact that there is presently no science of ,anufacturing


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,odels of the production process guiding their decisions and actions# Gowe.er0 due to

the

1 /sse,bled in 19&9 by the )ational /cade,y of 3ngineering of the Hnited tates#


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11


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lack of an e%plicit production philosophy0 such indi.idual paradig,s ha.e often e.ol.ed fro, beliefs or rules of thu,b that deri.e fro, personal e%perience


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12

>aterial0 "roductslabor

"roduction

process

ubprocessubprocess

/ !

Figure 1. The con$en%ional $ie) o& a *roduc%ion *roce a a con$erion *roce %ha% can 'e di$ided hierarchically in%o u'*rocee.

tate,ents 2 and A are especially related to the theories of control in a hierarchical

organiation# Con.entional accounting theory0 which supports this ,ode of control0 is

based on the following assu,ptions


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!y focusing on con.ersions0 the ,odel abstracts away physical flows between

con.ersions# hese flows consist of ,o.ing0 waiting and inspecting acti.ities# In a way0

1A


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this is a correct idealiationJ fro, the custo,er point of .iew these acti.ities are not

needed since they do not add .alue to the end product# Gowe.er0 in practice0 the ,odelhas been interpreted so that a?or

in.est,ents in new e8uip,ent are not the solution to a confused factory7


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2hese two ite,s correspond to the co,,on .iews on 8uality


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1+


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;2; y a te con)entional mo"el 'een a"opte"

5hy has the con.ersion ,odel been used in the first place0 when its drawbacks0 at least in

hindsight0 are so e.ident / clue to a possible answer is gi.en by ohnson and Kaplan o.ing 5aiting "roces*

Inspec

*sing / tion sing ! tion

cra

p

Figure 2. Produc%ion a a &lo) *roce! im*li%ic illu%ra%ion. The haded 'oxere*reen% non $alue-adding ac%i$i%ie in con%ra% %o $alue-adding *roceing ac%i$i%ie.

In essence0 the new conceptualiationA i,plies a dual .iew of production: it consists of

con.ersions and flows# he o.erall efficiency of production is attributable to both the

efficiency


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A )ote that there are se.eral related definitions that only partially co.er the i,portant features considered

here# (or e%a,ple the process definition of "all


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1B


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perfor,ed0 as well as the a,ount and efficiency of the flow acti.ities through which the

con.ersion acti.ities are bound together +#

5hile all acti.ities e%pend cost and consu,e ti,e0 only con.ersion acti.ities add .alue

to the ,aterial or piece of infor,ation being transfor,ed to a product# hus0 thei,pro.e,ent of flow acti.ities should pri,arily be focused their reduction or

eli,ination0 whereas con.ersion acti.ities ha.e to be ,ade ,ore efficient# his core

idea of the new production philosophy is illustrated in (igure A#

!ut how should flow processes be designed0 controlled and i,pro.ed in practice In

.arious subfields of the new production philosophy0 the following heuristic principles

ha.e e.ol.ed:

4educe the share of non .alue*adding acti.ities#

Increase output .alue through syste,atic consideration of custo,er re8uire,ents#4educe .ariability#

4educe the cycle ti,e#i,plify by ,ini,iing the nu,ber of steps0 parts and linkages#

Increase output fle%ibility#Increase process transparency#

(ocus control on the co,plete process#

!uild continuous i,pro.e,ent into the process#

!alance flow i,pro.e,ent with con.ersion i,pro.e,ent#

!ench,ark#

hese principles are elaborated in the ne%t section# In general0 the principles apply both

to the total flow process and to its subprocesses# In addition0 the principles i,plicitly

define flow process proble,s0 such as co,ple%ity0 intransparency or seg,ented control#

)ote that it is rarely possible to de.ise the best possible process by design onlyJ usually

the designed and i,ple,ented process pro.ides a starting point for continuous

i,pro.e,ent0 based on ,easure,ents of actual process beha.ior#


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+ In recent discussion on strategy0 the for,er has been called core co,petence0 the latter capability


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1E

Con)entional


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Value*adding acti.ity: /cti.ity that con.erts ,aterial and;or infor,ation

towards that which is re8uired by the custo,er#

)on .alue*adding acti.ity


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1D


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4educing the share of non .alue*adding acti.ities is a funda,ental guideline#

3%perience shows that non .alue*adding acti.ities do,inate ,ost processesJ usuallyonly A to 2' O of steps add .alue ost of the principles presented below address suppression of non .alue*adding

acti.ities# Gowe.er0 it is possible to directly attack the ,ost .isible waste ?ust byflowcharting the process0 then pinpointing and ,easuring non .alue*adding acti.ities

B#

Increae output )alue trou& ytematic coni"eration of cutomer re6uirement

his is another funda,ental principle# Value is generated through fulfilling custo,er

re8uire,ents0 not as an inherent ,erit of con.ersion# (or each acti.ity there are two

types of custo,ers0 the ne%t acti.ities and the final custo,er#

!ecause this sounds self*e.ident0 we again ha.e to ask why custo,er re8uire,ents

ha.e not been considered#

he organiational and control principles of the con.entional production philosophy

ha.e tended to di,inish the role of custo,er re8uire,ents# In ,any processes0

custo,ers ha.e ne.er been identified nor their re8uire,ents clarified# he do,inantcontrol principle has been to ,ini,ie costs in each stageJ this has not allowed for

opti,iation of cross*functional flows in the organiation#

he practical approach to this principle is to carry out a syste,atic flow design0 where

custo,ers are defined for each stage0 and their re8uire,ents analyed# $ther principles0


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B / detailed ,ethodology for ad,inistrati.e processes is presented0 for e%a,ple0 by Garrington


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1&


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especially enhanced transparency and continuous i,pro.e,ent0 also contribute to this

principle#

;=; Re"uce )aria'ility

"roduction processes are .ariable# here are differences in any two ite,s0 e.en though

they are the sa,e product0 and the resources needed to produce the, beyond ,ere confor,ance to gi.en specifications#

econdly0 .ariability0 especially of acti.ity duration0 increases the .olu,e of non .alue*

adding acti.ities# It ,ay easily be shown through 8ueue theory that .ariability increases

the cycle ti,e


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E here often are se.eral flows which unite or di.erge in the total production process# Gowe.er0 it is

generally possible to recognie the ,ain flow and side flows0 which ha.e to be assessed separately#


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19


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decrease of disruption of the production process due to change orders

easier ,anage,ent because there are fewer custo,er orders to keep track of#

he principle of cycle ti,e co,pression also has other interesting i,plications# (ro,the perspecti.e of control0 it is i,portant that the cycles of de.iation detection and

correction are speedy# In design and planning0 there are ,any open*ended tasks that

benefit fro, an iterati.e search for successi.ely better


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Figure 4. ycle %ime can 'e *rogrei$ely com*reed %hrough elimina%ion o& non

$alue-adding ac%i$i%ie and $aria'ili%y reduc%ion Berliner Brimon 1388.


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2'


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;=B Simplify 'y minimi@in& te num'er of tep an" part

$ther things being e8ual0 the .ery co,ple%ity of a product or process increases the

costs beyond the su, of the costs of indi.idual parts or steps# Con.entional accounting

shows the price differential of two ,aterials0 but not the additional costs created in thewhole production syste, by using two instead of one


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,aking the process directly obser.able through organiational or physical ,eans0

,easure,ents0 and public display of infor,ation#


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21


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In a theoretical sense0 transparency ,eans a separation of the network of infor,ation

and the hierarchical structure of order gi.ing easuring and ,onitoring i,pro.e,ent#

etting stretch targets


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orderliness0 cleanliness0 personal cleanliness and discipline


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22


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Continuous i,pro.e,ent is analyed in ,ore detail in section A#B#

;=4G +alance flo! impro)ement !it con)erion impro)ement

In the i,pro.e,ent of producti.e acti.ities0 both con.ersions and flows ha.e to be

addressed# !ut how should these two alternati.es be balanced

(or any production process0 the flow and con.ersion aspects each ha.e a different potential for i,pro.e,ent# /s a rule0

the higher the co,ple%ity of the production process0 the higher the i,pact of flow

i,pro.e,ent

the ,ore wastes inherent in the production process0 the ,ore profitable is flowi,pro.e,ent in co,parison to con.ersion i,pro.e,ent#

Gowe.er0 in a situation where flows ha.e been neglected for decades0 the potential for

flow i,pro.e,ent is usually higher than con.ersion i,pro.e,ent# $n the other hand0

flow i,pro.e,ent can be started with s,aller in.est,ents0 but usually re8uires a longer

ti,e than a con.ersion i,pro.e,ent#

he crucial issue is that flow i,pro.e,ent and con.ersion i,pro.e,ent are inti,atelyinterconnected:

better flows re8uire less con.ersion capacity and thus less e8uip,ent in.est,ent

,ore controlled flows ,ake i,ple,entation of new con.ersion technology easier

new con.ersion technology ,ay pro.ide s,aller .ariability0 and thus flow benefits#

herefore one is te,pted to agree with $hno0 who argues that 6i,pro.e,ent adheres toa certain order7


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appropriate any ,ore0 and a new goal 6paying upon deli.ery7 was adopted#


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2A


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* gaining superiority by co,bining e%isting strengths and the best e%ternal

practices#

/ detailed ,ethodology for bench,arking is presented by Ca,p any of the principles discussed abo.e are realied in the fra,ework of continuous

i,pro.e,ent# !ecause the concept is relati.ely new0 it is useful to analye and

co,pare it with inno.ation0 which has been the pri,ary fra,ework of analysis until

now#

he 5estern .iew on technological ad.ance,ent has seen product and process9 inno.ation as

the pri,e ,o.ers of change# Characteristic to both product and process inno.ation is that the

inno.ati.e features are e,bodied in a product or in production e8uip,ent# >ost often0

inno.ation is sti,ulated by e%ternal technological de.elop,ent or ,arket de,and# Inno.ation

is often seen as a breakthrough leap0 though incre,ental refine,ent is also accepted as a for,

of inno.ation# In ,any disciplines0 like econo,ics and industrial engineering0 the residual

technological progress that re,ains une%plained by inno.ation has been called learning#

I,ai


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o so,e e%tent continuous i,pro.e,ent parallels the traditional .iew on inno.ation:

they both incorporate incre,ental product and con.ersion process i,pro.e,ent#

Gowe.er0 continuous i,pro.e,ent is ,ore geared towards de.elop,ent of the flow

process than

9 In inno.ation literature0 the ter, 6process inno.ation7 refers to con.ersion process inno.ation rather

than to flow process inno.ation#


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2+


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con.ersions a?or Inno)ation:change Implementation

of ne!

tecnolo&y

Incre,ental Continuouchange impro)ement

(low process

Con.ersion

Figure 6. on%inuou im*ro$emen% and inno$a%ion! &ocu and aimed change.

he focus of continuous i,pro.e,ent is typically:eli,inating bottlenecks


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2B


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hus0 the new production philosophy pro.ides a .ision and focus for i,pro.e,ent and

inno.ation# It stresses i,pro.e,ent directed at the present constraints in the productionflow#

,eaurement in continuou impro)ement

>easures are e%tre,ely i,portant in the pursuit of lean production# >easures pro.ideaccess to continuous i,pro.e,ent by pinpointing i,pro.e,ent potential and

,onitoring progress achie.ed#

he traditional ,easures that ,ost often focus on costs0 producti.ity or utiliation rates0

ha.e been criticied fro, se.eral points of .iew# heir ,a?or proble,s include the

following:

they do not gi.e i,petus for continuous i,pro.e,entthey do not atte,pt to understand the sources of indirect costs and thus ,isdirect

attentionJ for e%a,ple0 the principle of allocating o.erhead cost in proportion to

direct labor focuses the cost reduction attention solely to direct labor easures should foster i,pro.e,ent rather than ?ust ,onitor it askell 1991=# rends are ,ore

i,portant than absolute .alues#

o,e of the new principles are also applicable to ,easure,ent itself:

i,plification# >easure,ent should not re8uire ,uch additional effort# here should


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not be too ,any different ,easures# /fter all0 ,easure,ent does not directly

add .alue to the product#


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2E


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>easures should be transparent and understandable# /ggregates are better than details0

physical ,easures better than financial0 and .isual feedback is ,ore useful than syste,sdata askell 1991=# 5hile costs are based on a

nu,ber of physical factors0 it is i,possible to influence these through cost controlJhowe.er0 it is possible the other way around0 to influence cost through ,anipulating

physical factors#

i,e as a suitable global ,easuring di,ension is suggested by talk and Gout


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2D


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Focu on meaura'le and ac%iona'le im*ro$emen%

he focus should be on actionable and ,easurable i,pro.e,ent0 rather than ?ust on

de.eloping capabilities# $f course0 defining .arious flow processes and focusing on

their bottlenecks to speed up and s,ooth out ,aterial and infor,ation flows ,eans ?ust

that# hort ter, successes then reinforce ,oti.ation for further i,pro.e,ent#

$riginally in I0 the o.erarching goal was to reduce or eli,inate in.entories# Gowe.er0reduction of in.entories unco.ered other proble,s0 which had to be sol.ed as a forced

response# Cycle ti,e0 space and .ariability ha.e also been used as dri.ers0 because they

too are increased by underlying proble,s# 3specially cycle ti,e pro.ides an e%cellent0easy to understand dri.er0 which can be i,pro.ed continually#

In$ol$emen%

3,ployee in.ol.e,ent happens naturally0 when organiational hierarchies are

dis,antled0 and the new organiation is for,ed with self*directed tea,s0 responsible for

control and i,pro.e,ent of their process


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or i,pro.ed in an orderly fashion# his has led to co,ple%0 uncertain and confused

flow processes0 e%pansion of non .alue*adding acti.ities0 and reduction of output .alue#


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2&


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3le.en principles for flow process design and i,pro.e,ent ha.e e.ol.ed# here is

a,ple e.idence that through these principles0 the efficiency of flow processes can beconsiderably and rapidly i,pro.ed#

Ta'le /. The %radi%ional and ne) *roduc%ion *hiloo*hie.

he traditional production philosophy

"roduction acti.ities are:

concei.ed as sets of operation or function0 which are

controlled0 operation*by*operation0 for leat cot0 and

i,pro.ed perio"ically with respect to pro"ucti)ity by i,ple,enting ne! tecnolo&y#

he new production philosophy

"roduction acti.ities are:

concei.ed as ,aterial and infor,ation flo! procee0 which arecontrolled for ,ini,al )aria'ility an" cycle time0 and

i,pro.ed continuouly with respect to !ate an" )alue0 and periodically with respect

to efficiency by i,ple,enting new technology#


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29


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= Contruction a acti)ity

o what degree do the proble,s associated with the con.entional production .iew0 asobser.ed in ,anufacturing0 also e%ist in construction his is the basic 8uestion we

address in this chapter# o answer it0 we first analye the traditional conceptual basis of

construction0 and then discuss the proble,s caused by these traditional concepts#/.ailable infor,ation on wastes in construction is su,,aried0 and the detri,ental

i,pact of the traditional concepts on de.elop,ent efforts in construction is presented#

Te tra"itional conceptuali@ation of contruction

Construction is a .ery old industry# Its culture and ,any of its ,ethods ha.e their rootsin periods before e%plicit scientific analysis# Gowe.er0 especially after the econd

5orld 5ar0 there ha.e been se.eral different initiati.es to understand construction and

its proble,s and to de.elop corresponding solutions and i,pro.e,ent ,ethods# 5e canrecognie strategic initiati.es like industrialiation0 co,puter integrated construction0

and total 8uality ,anage,ent# 5e also see operational and tactical techni8ues such as

pro?ect planning and control tools0 organiational ,ethods0 pro?ect success factors0 and producti.ity i,pro.e,ent ,ethods# 5hat conceptualiations ha.e been used in these

efforts by practicing builders and researchers

!y far the ,ost general concept see,s to be the understanding of construction as a set

of acti.ities ai,ed at a certain output0 i#e# con.ersions# his acti.ity .iew of

construction is shared both by the old traditions of construction and the newer ,ethods#

he traditional ,ethod of cost esti,ation is at the heart of this acti.ity .iew# he building


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purpose of construction pro?ect ,anage,ent is to create conditions that enable the tea,s who ,ake up

pro?ect organiations to carry out days*work efficiently#7


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A'


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hus0 the o.erall effects of re.isions0 repairs0 and rework on large pro?ects can be .ery

significant0 e.en when the indi.idual effects of specific functions and disciplines appear s,all and within 6nor,al7 acceptable practices#

!eyond this con.ersion ,odel0 what theories or fra,eworks ha.e been used in

construction /s odd as it ,ight see,0 there are hardly any other theoretical or conceptual fra,eworks in general use# /s elaborated below0 this conclusion is

suggested by te%tbook content0 research content0 and discussions by other construction

researchers#

3.en a rapid glance at the contents of te%tbooks on construction ,anage,ent shows

that they usually begin with a descripti.e account of a construction pro?ect


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he flaws of these ,ethods ha.e been obser.ed to .arying degrees and alternati.es

ha.e been sought# Gowe.er0 lacking a sound theory0 these efforts ha.e re,ained

insufficient#


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A1


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=24 Se6uential meto" of "ei&n an" en&ineerin&

In se8uential design and engineering0 the total task is di.ided into te,porally se8uential

tasks0 which are gi.en to different specialists for e%ecution# his has been thecon.entional ,ethod of organiing product de.elop,ent in ,anufacturing# In

construction0 the traditional approach to pro?ect e%ecution ore often than not0 the reason for this is the hierarchical organiation#

Control in a hierarchical organiation focuses on an organiational unit or a task0 the


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costs of which are to be ,ini,ied# his leads to ,a%i,iation of utiliation rates and

to large batches# his ,ode of control is characteried by both accu,ulation of work*

in*process


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A2


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between units or operations and disruptions due to ,aterial or infor,ation shortages#

he situation is further aggra.ated by specialiation which leads to an increase in thenu,ber of units or tasks#

/ typical construction e%a,ple ,ay be found in ,aterials ,anage,ent network# /n acti.ity is usually a part of the o.erall work

flow of a tea, or it is a co,plete work flow in itself# It is usually fed by a ,aterial flow#

5hen an acti.ity is a part of a wider work flow0 it is strongly affected by the pre.ious

acti.ity# he work tea, has to ,o.e fro, the pre.ious location0 and if the acti.ities arethe sa,e0 learning benefits are gained and the set*up ti,e reduced# he cost of

super.ision and control also depends on the continuity of the work flow# C"> networksdo not generally ,odel these issues#

5hen an acti.ity is a co,plete work flow

reports that in practice pro?ect planning is done by considering the spatial work flow of

tea,s0 rather than by C"> network analysis#

Gowe.er0 there is an o.erwhel,ing a,ount of contrary e.idence# 5hate.er flow in

construction we analye0 a tradition of neglect and ,is,anage,ent is found:


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AA


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"ro?ect planning: $wners start lu,p su, pro?ects with absurd uncertainties


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A+


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/s far as it is known0 there has ne.er been any syste,atic atte,pt to obser.e all wastes

in a construction process# Gowe.er0 partial studies fro, .arious countries can be usedto indicate the order of ,agnitude of non .alue*adding acti.ities in construction#

Gowe.er0 the figures presented tend to be conser.ati.e0 because the ,oti.ation to

esti,ate and share the, is greatest in leading co,panies0 which ,ay be near the best

practice# (urther,ore0 e.en an energetic effort to obser.e all 8uality proble,s does notreach all of the,# / wide .ariation due to local conditions0 pro?ect types0 construction

,ethods etc# ,ay also be anticipated#

uality costs are perhaps the best researched area# In nu,erous studies fro, different

countries0 the cost of poor 8uality design D& O

construction 1D O0 BB O and 22 O0 respecti.ely

,aterial supply 2' O and 1B O


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cooperation in strea,lining the ,aterial flow


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AB


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/s for work flow processes0 the a.erage share of working ti,e used in .alue*adding

acti.ities is esti,ated to be AE O


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nor,al0 e.eryday e.ents for the a.erage co,pany#7


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AE


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he original basis of CIC is acti.ity*oriented# /fter obser.ing a task poorly carried out0 na,ely

data co,,unication0 it is suggested that this task be co,puteriedA# Gowe.er0 here we again

confront the ,yopic .iew of i,pro.ing tasks or acti.ities in isolation fro, the flow#

In fact0 there is increasing e,piric e.idence that flow process proble,s0 like e%cessi.e

frag,entation and seg,entation0 effecti.ely ha,per the i,ple,entation of integrationtechnology


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4ecently0 these issues ha.e been increasingly addressed in the fra,ework of organiational integration#


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AD


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B Contruction a flo!

Construction should be .iewed as co,posed of flow processes# In the following0 a .iew

of the construction pro?ect based on flows and their associated wastes and .alues is

gi.en# >easuring flows in construction is then co,,ented upon#

he ,ost acute flow proble,s of construction are caused either by traditional design0 production and organiation concepts0 or the peculiarities of construction# hus0 these

issues necessitate special consideration# /fter e%a,ining solutions to the proble,s

caused by the traditional ,anagerial principles0 the i,pact of construction peculiaritieson process control and i,pro.e,ent is analyed#

aking flows as the unit of analysis in construction leads to deep changes of concepts

and e,phasis# his initial interpretation will only scratch the surface#

%lo! procee in contruction

here are two ,ain processes in a construction pro?ect:

· (eign *roce: is a stagewise refine,ent of specifications1 where .ague needs

and wishes are transfor,ed into re8uire,ents0 then .ia a .arying nu,ber of

steps0 to detailed designs# i,ultaneously0 this is a process of proble, detectionand sol.ing# It can be further di.ided into indi.idual subprocesses and

supporting processes#

· on%ruc%ion *roce: is co,posed of two different types of flows:

· >aterial process consisting of the flows of ,aterial to the site0 including processing and asse,bling on site#

· 5ork processes of construction tea,s# he te,poral and spatial flows of

construction tea,s on site are often closely associated with the ,aterial processes#

$ther processes0 which control or support the ,ain processes0 include:

"ro?ect ,anage,ent process by the owner#Fesign ,anage,ent process by the engineering or design pro?ect ,anager#

Construction ,anage,ent process0 where the detailed design is transfor,ed into a

construction;fabrication plan and into day*to*day coordination and control of processes on site or in a factory#

he processes ,ay be characteried by their cost0 duration and the .alue for thecusto,er# he .alue consists of two co,ponents: product perfor,ance and freedo,

fro, defects


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(or ,ore detailed discussion0 see


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A&


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he cost of design is ,ade up of costs of .alue*adding acti.ities and waste# he waste

in the design process is for,ed byrework


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A9

Value loss

due to design

otal 3%tra cost dueValue loss dueto

construction

costs to design otal

3%tra cost due .alue

to construction

!est3%tra cost practice

otal costsdue to design

costs inefficiencies!est

practice

costs

Fesign Construction Value of the

costs costs constructed facility

Figure 5. The deciion i%ua%ion &rom %he *oin% o& $ie) o& %he clien%. No%e %ha%

deign and con%ruc%ion dura%ion can 'e analy9ed imilarly %o co%.

heoretical

best .alue Value

loss

!est

practice

otal .alue

costs )on .alue

adding costs

otal )on .alue

adding costs Value adding

costs Value adding costs


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costs

Fesign Construction Value of the

costs costs constructed facility

Figure :. The *roce im*ro$emen% *o%en%ial &or %he 'e% *rac%ice organi9a%ion. ;gain %ime hould 'e analy9ed in a *arallel &ahion %o co%.

Co,pare this analysis with the con.entional discussion on the di,inishing degree of

influence of decisions on pro?ect cost during the progress of the pro?ect


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+'


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influencing costs0 ti,e and .alue within the pro?ect is e8ui.alent to ,anipulating flow

characteristics0

cost0 ti,e and .alue are also dependent on the long ter, efforts of participating

organiations for continuous i,pro.e,ent#

,eaure for contruction

It is e.ident that the con.entional ,easures of construction0 which ,ost often focus on

cost or producti.ity0 fail to ,ake waste .isible and to sti,ulate continuous

i,pro.e,ent0 as argued in ection A#E# )ew ,easures are needed# Clearly0 this the,e is

an open in.itation to research and de.elop,entA#

hree of the .isited co,panies were in the process of de.eloping or already using new ,easures

and ,easure,ents syste,s in connection to continuous i,pro.e,ent efforts+#

he following discussion is confined to illustrating new ,easures and to co,,enting

on difficulties in establishing suitable ,easures for co,parisons and bench,arking#

>easure,ent data are needed for two purposes: for dri.ing internal i,pro.e,ent in the

organiation0 and for targeting and co,parison across pro?ects and organiations# (or

organiations per,anently participating in construction0 both sets of ,easures arei,portant# (or a one*ti,e owner0 the latter type of perfor,ance data is of interest#

In the following0 construction related ,easures are illustrated0 based on the

re8uire,ents presented in section A#E:

5aste: uch issues as nu,ber of defects0 rework0 nu,ber of design errors ando,issions0 nu,ber of change orders0 safety costs0 e%cess consu,ption of

,aterials and the percentage of non .alue*adding ti,e of the total cycle ti,e for

a particular work or ,aterial flow ,ay be addressed#

Value: he .alue of the output to the internal or e%ternal custo,er often has to be

e.aluated sub?ecti.ely# (or e%a,ple0 an aggregate ,easure for 8uality of industrial plants0 based on sub?ecti.e .iews0 has been de.eloped in a current

study at CI(3


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his for,at is used to present anecdotal e.idence fro, the co,panies .isited by the author#

(or discussion on ti,e based co,petition in construction0 see


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+1


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co,ple%ity and uncertainty and to link efficiency and effecti.eness targets to the degree

of difficulty ,et#

/s for ,easure,ent data used for co,parison and targeting0 the proble,s stated abo.e

are ,ore se.ere# Gowe.er0 they ,ay be sol.ed by focusing on rates of i,pro.e,ent

rather than on absolute .alues# his has other benefits as well:

Fifferences in definition and data collection are to a great e%tent filtered away#Fifferences in pro?ect co,ple%ity0 uncertainty0 etc# between .arious co,panies are

hea.ily reflected in the absolute .aluesJ howe.er0 it is reasonable that a

logarith,ic ,easure0 like hal.ing ti,e0 is co,parable#

$.erall rate of i,pro.e,ent is the single ,ost i,portant ,easure in the long ter,#

Gal.ing ti,e or percent change per year are si,ple and easy to understand#

/s obser.ed in bench,arking practice0 infor,ation on rates of i,pro.e,ent0 to be

operational0 should be acco,panied by infor,ation about ,eans for triggering that

i,pro.e,ent #

In spite of all difficulties in finding co,,ensurate data0 an i,portant ,easure for co,parison

and targeting is surely the world class le.el0 that is0 the absolute .alue of achie.e,ent of the

best co,panies in the world# Gowe.er0 for targeting0 it is useful to know the ti,e it will take to

reach this le.el0 which is reflected in the rate of i,pro.e,ent0 discussed abo.e#

he industry a.erage


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and


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+2


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tightening change control towards the end of the design process# In co,parison to the

traditional se8uential design process0 iteration cycles are transferred to the earlier phases through cross*functional tea,work# /lso o.erlapping of phases is usedJ

howe.er0 intense infor,ation e%change is re8uired# Co,pression of the design ti,e0

increase of the nu,ber of iterations and reduction of the nu,ber of change orders are

three ,a?or ob?ecti.es of concurrent engineering#In construction0 .arious partial solutions ha.e been i,ple,ented for re,edying the

e.ident proble,s of the traditional approach# >ost solutions concern organiational

rethinking# (or e%a,ple0 in design*build contracts0 the contractor gains ,ore influencein design solutions# In solutions in.ol.ing construction ,anage,ent0 an additional party

is recruited for taking care of the flows#

"erfor,ance specification refers to a structured design procedure0 where there8uire,ents are ,ade e%plicit0 so that fir,s can offer their own technical solutions

corresponding to the re8uired perfor,ances


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are still scarce and tentati.e# 3%peri,entation0 de.elop,ent and research are needed#


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+A


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B;= %rom net!or> plannin& to flo! plannin&

In both work planning and ,aterials ,anage,ent0 the e,phasis should change to

co,plete flow processes rather than discrete acti.ities# !irrell


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repetition:


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++


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roughly si,ilar pro?ects and tasks recur E# hus0 it has to be stressed that the proble,s

associated with one*of*kindness affect only certain processes in any pro?ect#

Hsually there is significant input into the design process by the client0 who is often a

one*ti,e participant in the process and thus does not ha.e the benefit of learning fro,

prior pro?ect cycles#

Pro'lem o& *roce con%rol and im*ro$emen%

here are se.eral ,a?or proble,s of process control and i,pro.e,ent related to one*of*

a*kind production#

)o co,plete feedback cycles are possible because the product is costly: what would be

a prototype to be debugged and de.eloped further in ,anufacturing0 is the end product

in construction#

he input by a lay client tends to be incoherent and unorganied0 often acti.ated by

e%posure to detailed design solutions# uch corrections of o,issions in later phases of

the pro?ect disrupts the otherwise s,ooth flow of acti.ities#he general proble, in the production of one*of*a*kind buildings is that the

configuration of the flows has to be specifically designed# here are acti.ities in the

flow that are difficult to control because of no.elty# In one*of*a*kind tasks0 figuring outthe respecti.e goals and constraints is error*prone and ti,e*consu,ingJ the benefits of

learning and continuous i,pro.e,ent are not at hand# /lso0 the coordination of the

pro?ect is ha,pered by duration uncertainty and unknown characteristics of one*of*a*kind acti.ities#

(ro, the point of .iew of process i,pro.e,ent0 ,easuring is a concern: one*of*a*kind

pro?ects are not .iewed as co,parable0 and incre,ental progress fro, pro?ect to pro?ect

has been difficult to percei.e#

o su, up0 the following principles for flow design and i,pro.e,ent are difficult to realie:

reduction of .ariability0 continuous i,pro.e,ent0 enhance,ent of transparency0 co,pression of


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E It is often argued that construction pro?ects are uni8ue0 and especially different fro, ,anufacturing in

this aspect# Gowe.er0 clai,s of uni8ueness of particular plants abound in ,anufacturing as well


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+B


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or learning fro, corresponding earlier pro?ects# /cco,plishing no.el tasks on site can

be facilitated by planning and training with ,ock*up ,odels# Interestingly0 it is a practice in apan to publish solutions used in uni8ue pro?ects in scholarly ?ournals#

he ,anage,ent of the client re8uire,ent for,ulation process is another need#

yste,atic in.estigation of re8uire,ents and client in.ol.e,ent in conceptual design

produce upfront a re8uire,ents list0 which facilitates progress in subse8uent phases#

5ith regard to site acti.ities0 the proble,s of one*of*a*kind tasks can be re,edied withhigh 8uality docu,ents and clear instructions# Costly acti.ities of sufficient duration

warrant careful ,ethods study and i,pro.e,ent# Continuous planningD will pre.ent

non .alue*added ti,e fro, inflating on site#

In general0 the proble,s of one*of*a*kind nature are co,pounded by the two ne%t

proble,s: production on site and and te,porary organiation&#

B=; Site pro"uction

harac%eri9a%ionConstruction production is typically carried out at the final site of the constructed

product0 often inside the e.ol.ing product

Pro'lem o& *roce con%rol and im*ro$emen%

here are four ,a?or process control and i,pro.e,ent proble,s with respect to site

production:

Variability proble,s: here is usually little protection against ele,ents or intrusion0

rendering operations prone to interruptions# "er,anent safety fi%tures cannot beused in the e.ol.ing en.iron,ent# Local ,aterial and labor input often has to be

used0 potentially adding to uncertainty# $ther areas of uncertainty include site

geology and additional en.iron,ental factors#Co,ple%ity proble,s: he spatial flow of work stations


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In ,anufacturing0 there are also great difficulties in transfering i,pro.e,ent fro, plant to plant within

one co,pany


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+E


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oriented construction so,e acti.ities such as inspection0 storage0 sorting etc#0 can be

pushed upstrea, in the ,aterial flow#

he ne%t solution is to arrange necessary protection by ,eans of te,porary enclosures0

if feasible and cost*effecti.e#

ite production sets high de,ands on planning because of its uncertainty0 changing

work en.iron,ent and nu,erous coordination needs# "lanning of ,aterial and work flows is ti,e consu,ing0 and in practice it is poorly e%ecuted# 4esearch shows that

,ore ,eticulous planning0 than currently is usual0 is beneficial1'

# he difficulty of

spatially coordinating the work flow can be alle.iated by establishing ,ulti*skilled

work groups0 which coordinate through ,utual ad?ust,ent#

In practice0 site operations are rather poorly syste,atiedJ only a handful of co,panies

ha.e standard ,ethods for .arious site operations


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1'ee


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+D


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increasing the share of non .alue*adding acti.ities# Gowe.er0 by i,ple,enting

structural solutions these peculiarities


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+&


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can be a.oided or at least ,ini,ied# Various operational solutions alle.iate control

proble,s and i,pro.e,ent proble,s respecti.ely#

In any case0 the general principles for flow design0 control and i,pro.e,ent apply#

Construction peculiarities cannot ser.e as an e%cuse for neglect of process

i,pro.e,ent#

hese solutions will be refined and no.el solutions will surely e,erge through

practical i,pro.e,ent efforts#

Ta'le 4. O$er$ie) on *ro'lem rela%ed %o con%ruc%ion *eculiari%ie and corre*onding

olu%ion. Proce con%rol re&er %o %he managemen% o& a *ro=ec% *roce im*ro$emen%

%o %he de$elo*men% e&&or% o& %he *ermanen% organi9a%ion in con%ruc%ion deigning

manu&ac%uring o& ma%erial and com*onen% con%rac%ing.

Peculiarity Proce ProceStructural Operational

Operational

control impro)ementolution

olution forolution for

pro'lem

pro'lem control impro)ement$ne*of*a*kind )o prototype $ne*of*a*kind >ini,ie the Hpfront 3nhance

cycles processes do one*of*a*kind

re8uire,ents fle%ibilit

y of

Hnsyste,atic not repeat0 thus content in the analysis products and

client input long ter, pro?ect et up artificial ser.ices toCoordination

of

i,pro.e,ent

cycles co.er

a

wider

uncertai

n 8uestionable !uffer

.ariety of

needs

acti.ities uncertain tasks /ccu,ulatefeedback

infor,ation

fro, earlier

pro?ectsite production 3%ternal Fifficulty of >ini,ie the Hse enclosures 3nhance

uncertainties: transferring acti.ities on etc# for planning and

weather etc#

i,pro.e,ent site in

any

eli,inatin

g risk analysis

Internal across sites ,aterial flow

e%ternal capabilit

y

uncertainties

solely

in

uncertaint

y

and

procedure

s and Fetailed and yste,atiedco,ple%ities: skills continuous work

flow inter* planning procedures

dependencies0 >ulti*skilled

changingworktea,s

layout0

.ariabilit

y of


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producti.ity

of

,anual work e,porary Internal Fifficulty of >ini,ie ea, building Integrate flowsorganiation uncertainties: sti,ulating and te,porary during the through

e%chang

e of accu,ulating

organiational pro?ect

partnershipsinfor,ation i,pro.e,ent interfaces

across across


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+9


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Concluion

he .iew of a construction pro?ect based on flow processes leads to theoretical

understanding and to practical guidelines for i,pro.e,ent#

heoretically0 the causes for the chronic proble,s in construction are clarified by pinpointing the generic process proble,s fro, which they originate# he proble,s of construction fall into two different clusters of causes# he first is the application of

traditional design0 production and organiation concepts0 which in the course of ti,e

ha.e beco,e inefficient# econdly0 construction has peculiarities which ha.e not been

ade8uately handled# hese issues necessitate special consideration in regard to a.oidingor alle.iating their detri,ental i,pact on process control and i,pro.e,ent#

5ith respect to practical application0 this approach pro.ides for e.aluation of e%isting flows


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B'


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Implementation of te ne! pro"uction piloopy in

contruction

Preent tatu of implementation: eDperience an" 'arrier

44 Initial implementation limite" 'y 'arrier

In the construction industry0 interest in the new production philosophy has grown rather

slowly# hree ,a?or thrusts of i,ple,entation can be discerned1:

he new approach0 in its I*oriented for,0 has been used in ,anufacturing oriented parts of the construction industry0 like in the production of windows0 ele.ators

and prefabricated housing#

In ,ainstrea, construction0 8uality*based efforts ha.e been launched by a growing

nu,ber of organiationsJ this includes > but also such de.elop,ents as

partnering0 tea, building0 continuous i,pro.e,ent and constructability#

In se.eral countries0 there are initiati.es to change the pro?ect organiation and

procure,ent ,ethods so that obstacles for process i,pro.e,ent will beeli,inated#

/ll in all0 howe.er0 the o.erall adoption of the new philosophy in construction is rather

li,ited in scope and ,ethods# 5hat are the reasons for this reluctance

he following barriers to the i,ple,entation of these ideas in construction can beobser.ed:

Cases and concepts presented to illustrate the new approach


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new production philosophy ha.e already been incre,entally introduced# !ennett


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B1


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42 Contruction u'procee of manufacturin& caracter

Currently so,e construction subproducts are produced in processes that possess a

,anufacturing character# he asse,bly of such co,ponents with the building fra,e

usually represents a ,inor share of the total costs# 5indows0 doors0 ele.ators0 prefabricated concrete co,ponents0 and prefabricated houses0 are e%a,ples of this kind

of ,anufactured product# any supplying fir,s ha.e ac8uired 8uality certification according to the I$ standard#

he application of the new production philosophy is least proble,atic in this part of the

construction industry: the ,ethods and techni8ues de.eloped in ,anufacturing can be

applied directly# Gowe.er0 e%cept for 8uality ,anage,ent techni8ues0 only a ,inor fraction of the factories and plants deli.ering to construction sites ha.e begun to

i,ple,ent the new philosophy# It ,ay be anticipated that this transfor,ation will

proceed rapidly after ha.ing gained initial ,o,entu,# hus0 industrialied construction,ight gain co,petiti.e benefits sooner than site construction#

4; ,aintream contruction$nly the 8uality oriented approaches ha.e been applied to any considerable e%tent in

the ,ainstrea, construction world# he 8uality issues ha.e recei.ed increasingattention since the beginning of the 19&'@s0 and construction specific interpretations of

the general 8uality ,ethodologies ha.e been published progra,s# he thrusts in

those progra,s are:

definition and standardiation of work processes e,phasis on custo,er .alue and .ariability reduction#

5hile 8uality ,anage,ent has pro.ided considerable direct benefits0 it has also ser.ed

as a starting point for process i,pro.e,ent# Gowe.er0 continued progress and widening


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of

2 ee the forthco,ing CII report 6I,ple,entation "rocess for I,pro.ed uality7#


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B2


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the,es considered see,s to be so,ewhat proble,atic# he basic proble, is that 8uality

,anage,ent basically addresses only a partial


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Infor,ation is this paragraph is based on trade ?ournals and oral co,,unication#

)ote that 6se8uential procedure7 has 8uite a different ,eaning than the ter, 6se8uential ,ethod of pro?ectorganiation7 discussed earlier#


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BA


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5aste reduction# he goal is to reduce non .alue*added ti,e due to e%cessi.e

specialiation: howe.er0 other waste co,ponents are not as e%plicitly attacked#

Variability reduction# 5ith se.eral strict due dates and 8uality control points during the

pro?ect0 defects and proble,s do not easily ,igrate downstrea,# "replanning is

facilitated through reduced e%ternal uncertainty#

Cycle ti,e co,pression# e8uence cycle ti,e


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he goal of this new building process is to re,o.e the causes of the current inherent

proble,s in construction


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B+


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design and final product


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construction# /ll in all0 e,pirical in.estigations are needed for clarifying the

significance of these new organiational ,odels for process i,pro.e,ent andinno.ation#


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BB


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2 Implementation of proce impro)ement 'y en&ineerin& an"

contruction or&ani@ation

he inherent reco,,endation of the new philosophy to construction practitioners is clear: the

share of non .alue*adding acti.ities in all processes has to be syste,atically and persistently

decreased# Increasing the efficiency of .alue*adding acti.ities has to be continued in parallel#

he basic i,pro.e,ent guideline is thus: get started0 define processes0 ,easure the,0locate and prioritie i,pro.e,ent potential0 i,ple,ent i,pro.e,ent and ,onitor

progressX e.eral pro.en step*to*step ,ethodologies that are useful e.en if ,ost are

narrow and not construction oriented


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up


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BE


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?ust a few principles and techni8ues# If these are successfully institutionalied0 adoption

of further principles will be ,ore easily accepted#

i.en the relati.ely high share of waste in construction at present0 it is e.ident that

notable gains ,ay be achie.ed in ,ost organiations e.en by well directed initial

efforts# 5aiting for a consolidation of construction specific i,ple,entation

,ethodology * which certainly will happen * is no e%cuse for sticking to the oldroutines#

Re"efinin& ma(or "e)elopment effort in contruction

In ,any countries0 ,a?or resources ha.e been and are currently channeled to such

de.elop,ent targets as industrialiation0 construction safety0 co,puter integrated

construction and construction auto,ation# It is of pri,e i,portance that they are

redefined in ter,s of the new conceptual basis#

;4 In"utriali@ation

Industrialiation has been discussed in se.eral conte%ts abo.e# Gere we su,,arie:

Industrialiation usually lengthens co,plete flow processes and ,akes the, ,oreco,ple% than in con.entional site construction


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regulations in daily work#


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BD


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$ne co,pany .isited by the author had achie.ed a dra,atic i,pro.e,ent in safety through general

i,pro.e,ent in engineering and planning processes0 the i,ple,entation of $"*,ethod0 and other

safety ,easures# In a period of fi.e years0 the $G/ recordable accident rate was reduced by 9+ O0 and

the lost ti,e accident rate by &+ O#

/nother co,pany had also achie.ed a steady decrease in safety rates and costs ,ainly through

syste,atic safety ,anage,ent and planning


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B&


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Knowledge*based syste,s ,ay be used for pro.iding si,plification ad.ice

# he

current guidelines hea.ily stress process i,pro.e,ent before auto,ation


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e.en if still sub?ect to final e.aluation0 strongly indicate that organiational integration had a considerably

larger positi.e i,pact on plant 8uality than technical integration in the pro?ects studied#


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B9


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Characteristic features of integrated construction engineering are the following


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D he discussion is based on


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E'


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"reli,inary /nalysis of the acti.ities in the work flowstage

Value adding ac%i$i%ie Non-$alue adding

ac%i$i%ie

Controllability of the 3li,ination or si,plifi* process cation

tage 1 4educed .ariability "rocess i,pro.e,ent0

design i,pro.e,ent

"re*auto,ation limina%ed

ac%i$i%y ac%i$i%y

tage 2 i,ple and cheap /uto,ationtechnology with si,ple

technology

/uto,ation

tage A Gigh technology

Figure 8.


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E1


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process i,pro.e,ent0 processes in construction0 in general0 are not well controlled# /s

a conse8uence of this0 the share of waste is considerable in construction# In ,ostconstruction acti.ity flows0 it is ,ore profitable to initiate process i,pro.e,ent

acti.ities than to auto,ate parts of the present acti.ity flow# $n the other hand0 a

si,plification of the respecti.e acti.ity flow0 often a result of process i,pro.e,ent0

decreases the in.est,ent needs for auto,ation and thus increases its profitability#"rocess i,pro.e,ent is both econo,ically and technologically a precondition for

auto,ation in construction#

$f course there are cases0 especially in hea.y ci.il engineering0 where operations

already are highly ,echanied or auto,ation is necessary for safety reasons#

/uto,ation with high technology ,ay be the right goal in these cases#

In practice0 the need for process i,pro.e,ent has not often been clearly recognied0

and conse8uently there is a twofold attitude to construction auto,ation# / so,ewhat

,isplaced opti,is, is shown especially by researchers&0 who do not always see the

necessity of getting construction under control as the first step towards auto,ation# $n

the other side0 the construction industry .iews auto,ation with great doubts0 because itis well aware of the out of control situation# Gowe.er0 the industry does not usually percei.e any re,edy for s,oothing the way for auto,ation#

herefore0 construction auto,ation research should also in.estigate the stages preceding auto,ation


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curricula# It is not an e%aggeration to say that all books ha.e to written anew0 and all old

truths ha.e to be reconsidered# /ccounting pro.ides another e%a,ple#

&Including the present writer0 before his con.ersion to flow thinkingX


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E2


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/s for construction ,anage,ent and engineering0 there is yet hardly any sign of a

paradig, shift# Gowe.er0 this field can a.oid addressing the sa,e funda,ental8uestions with which the neighboring fields are currently struggling#

he lagging response of acade,ic research and teaching seriously ha,per the

introduction of the new philosophy in construction# In conse8uence0 theoretical

understanding of the new approach does not accu,ulateJ howe.er0 such understandingis sorely needed for ,aking the new approach teachable and researchable#

hus0 it is urgent that acade,ic research and education address the challenges posed by

the new philosophy# $therwise0 a decreased rele.ance of acade,ic research will be the

outco,e#

=2 Lac>in& foun"ation of contruction mana&ement

It was argued earlier0 in section +#10 that our e,pirical knowledge and theoretical

understanding of construction is shallow and frag,ented# 5e know little of what is

happening in construction pro?ectsJ only in the last few years has the e%tent of 8uality

de.iations and costs0 for e%a,ple0 been sub?ected to direct analysis# Gowe.er0 8uality

costs are only the tip of the iceberg of all non .alue*adding costs# Construction relatedtheories0 or sound action principles based on the,0 are scarce#

It see,s that the distribution of the present research efforts in construction is not

balanced# he great ,a?ority of long ter, research undertakings ai, at applying new

tools fro, other technological fields0 like infor,ation technology0 artificial intelligence

and robotics0 to construction tasks0 whereas the conceptual and theoretical foundationsof construction get rather ,odest attention# Gowe.er0 as argued earlier0 ,a?or payoffs

could be realied through de.eloping these foundations#

It is not an e%aggeration to say that the new conceptualiation opens a practically new

research frontier# /s stated earlier0 the de.elop,ent of the new production philosophy

has been based on indi.idual .ision and prag,atic0 shop*floor e%peri,ents rather than breakthroughs in the theory# he practical .alidity of the philosophy has been pro.ed in

real life i,ple,entations# hus0 rigorous .alidation and e%planation of these principles

and ,ethods should be included in the research agenda# 3%a,ples of new research

the,es raised by the new conceptualiation include the following:

concepts and ta%ono,ies for defining design and construction processes

flow oriented site production planning and control tools

,easures for construction processes

new non*hierarchical organiation for,s for site work

procure,ent ,ethods which ad.ance process i,pro.e,ent#

=; %ormali@ation of te foun"ation

Gowe.er0 increased knowledge of foundations is not sufficientJ the foundations ha.e to be for,alied# In ,anufacturing science0 this has been suggested by se.eral authors#

he Co,,ittee on (oundations of >anufacturing states that there is a need for ane%plicit core set of principles0 on the basis of which the ,anufacturing process0 as a

totality0 could be analyed0 designed0 ,anaged and i,pro.ed


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,odel based reasoning0 a ,odel0 heuristics0 etc# are for,alied for the sub?ect

considered#


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EA


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he endea.or of "lossl


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E+


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7 Summary/ new production philosophy has e,erged0 with origins tracing back to de.elop,entand e%peri,ents of the I production syste, and 8uality control in apan in the 19B'@s#

)ow the new production philosophy0 regardless of what ter, is used to na,e it


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deteriorate flows by .iolating the principles of flow process design and i,pro.e,ent#

/s a conse8uence0 there is considerable waste in construction# he proble,s tend toco,pound and self*perpetuate#


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EB


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In pro?ect control0 firefighting current or loo,ing crises consu,es ,anage,ent

resources and attention so totally that there is little roo, for planning0 let alonei,pro.e,ent acti.ities# Gowe.er0 because con.entional ,easures do not address it0 this

waste is in.isible in total ter,s0 and is considered to be inactionable# I,pro.e,ent

efforts0 like industrialiation and co,puter integrated construction0 ha.e often been

ha,pered by their neglect of flow aspects#(ollowing the lead of ,anufacturing0 the ne%t task is to reconceptualie construction as

flows# he starting point for i,pro.ing construction is to change the way of thinking0

rather than seeking separate solutions to the .arious proble,s at hand#

hus0 it is suggested that the infor,ation and ,aterial flows as well as work flows of

design and construction be identified and ,easured0 first in ter,s of their internal waste


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industrialied construction0 co,puter integrated construction and construction

auto,ation will be redefined in order to acknowledge the needs for flow i,pro.e,ent# )ew organiational solutions for construction pro?ects will be introduced to facilitate

flow i,pro.e,ent as well as inno.ation#


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EE


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Current acade,ic research and teaching in construction engineering and ,anage,ent isfounded on an obsolete conceptual and intellectual basis# It is urgent that acade,ic research and

education address the challenges posed by the new philosophy# he first task is to e%plain the

new philosophy in the conte%t of construction# (or,aliation of the scientific foundations of

construction ,anage,ent and engineering should be a long ter, goal for research#


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ED


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+i'lio&rapy

/kao0 Wo?i / och helhetssynen * en sa,,anfattning# In: $*tuotanto rakennusalalla# 4IL

K1AE# uo,en 4akennusinsinYYrien liitto# "p# +9 * B

/yres0 4obert H# 19& Co,ple%ity0 4eliability0 and Fesign: >anufacturing I,plications# >anufacturing4e.iew0 Vol# 10 )r 10 >arch 19&&0 pp# 2E * AB#

!allard0 lenn# 19&9# "resentation to the Construction Industry Institute 3,ployee 3ffecti.eness ask

(orce# >arch 9# 1D p#

!arkan0 "hilip# 1991# trategic and actical !enefits of i,ultaneous 3ngineering# Fesign >anage,ent

ournal0 pring 1991# "p# A9 * +2#

!arrie0 Fonald # "aulson0 !oyd C# 19&+# "rofessional Construction >anage,ent# >craw*Gill0 )ew

Work# B+' p#

!audin0 >ichel# 199'# >anufacturing syste,s analysis with application to production scheduling#

Wourdon "ress0 3nglewoof Cliffs0 )# AE' p#

!ell0 L#C# tukhart0 # 19&D# Costs and !enefits of >aterial >anage,ent yste,s# ournal of

Construction 3ngineering and >anage,ent0 Vol# 11A0 )o# 20 pp# 222 * 2A+#

!endell0 /#0 Fisney0 # "rid,ore0 5#/# 19&9# aguchi >ethods: /pplications in 5orld Industry# I(

"ublications;pringer0 !edford# A99 p#

!ennett0 ohn# 1991# International Construction "ro?ect >anage,ent: eneral heory and "ractice#

!utterworth*Geine,ann0 London# A&D p#

!ranger0 "ierre# 19&D# Les nou.elles rZgles de la production# Funod0 "aris# 212 p#

!erliner0 Callie !ri,son0 a,es /# anage,ent for oday@s /d.anced

>anufacturing# Gar.ard !usiness chool "ress0 !oston# 2BA p#

!ernold0 Leonhard 3# 19&9# i,ulation of non*steady construction processes# ournal of Construction

3ngineering and >anage,ent0 Vol# 11B0 )o# 20 une0 pp# 1EA * 1D

!ernold0 Leonhard 3# reseler0 ohn (# 1991# Vendor /nalysis for !est !uy in Construction# ournal of

Construction 3ngineering and >anage,ent0 Vol# 11D0 )o# +0 Fece,ber# "# E+B#

!irrell0 eorge # 19&'# Construction "lanning * !eyond the Critical "ath# ournal of Construction

Fi.ision0 /C30 Vol# 1''0 )o# C$A0 ep# 19D+0 pp# 2'A * 21'#


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E&


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!irrell0 eorge # 19&E# Criticis, of C"> for "ro?ect "lanning /nalysis# ournal of Construction

3ngineering and >anage,ent0 pp# A+A * A+B#

!lack0 # 1991# he Fesign of the (actory with a (uture# >craw*Gill0 )ew Work# 2AA p#

!lackburn0 #F# #(# Gout0 #># 1991# he (allacy of the $.erhead uick (i%# Gar.ard !usiness 4e.iew0

uly*/ugust0 pp# 9A * 1'1#

!obroff0 acotte Ca,pagnac0 3liabeth# 19&D# La d,arche s8uentielle de la 3*!"# "lan

Construction0 "aris# 2'E p#

!urati0 a,es L#0 >atthews0 >ichael (# Kalidindi0 #)# 1991# uality >anage,ent in Construction

Industry# ournal of Construction 3ngineering and >anage,ent0 Vol# 11D0 )o# 20 pp# A+1 * AB9#

!urati0 a,es L#0 >atthews0 >ichael (# Kalidindi0 #)# 1992# uality >anage,ent $rganiations and

echni8ues# ournal of Construction 3ngineering and >anage,ent0 Vol# 11&0 )o# 10 pp# 112 * 12D#

!urati0 a,es L#0 (arrington0 odi # Ledbetter0 5illia, !# 1992# Causes of uality Fe.iations in

Fesign and Construction# ournal of Construction 3ngineering and >anage,ent0 Vol# 11&0 )o# 10 pp# A+ *

+9#

!urbidge0 ohn L# 199'# "roduction control: a uni.ersal conceptual fra,ework# "roduction "lanning

Control0 .ol# 10 no# 10 pp# A * 1E#

!Tttre ,aterialhandling pU bygget# 199'# !H( infor,erar nr# 9':2'# 1E p#

Ca,p0 4obert C# 19&9# !ench,arking: he earch for Industry !est "ractices that Lead to uperior

"erfor,ance# /C uality "ress0 >ilwaukee# 299 p#

Carothers0 # Garlan r# /da,s0 >el# 1991# Co,petiti.e /d.antage through Custo,er Value: he 4oleof Value*!ased trategies# In: tahl0 >## !ounds0 #># anage,ent of Co,ple%ity# loan >anage,ent 4e.iew0 (all0 pp# DA * &'#

Cia,pa0 Fan# 1991# he C3$@s 4ole in i,e*!ased C

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