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c2Labor Productivity Impactof Varying Crew Levels

Donald J. Cass, CCEINTRODUCTION

Constructions productionoriented,with bothprogress ndperformance ntinuously equated o total quantitiesof work n place.It is, unfortunately,a fact of life that, on any givenconstruction rojectworkday, here areno-shows nd abor replacementor workerswho havebeen erminatedor havequit. These abor no-showsmissiig crewmembers) nd replacementsnew crewmembers) avea very insidiousproductivity mpact.This labor productivity mpact,which s not fully understood or recognized ithin the wnstruction industry, s the burdenof increasedlearning mposedupon both reduced,and newlyaugmented ork crews.A situation,which will be labeled hephenomenon of vmyingcrew evel, ls the impositionof increasedearningon reducedworkcrews. This increasedearning derives rom incomplete rews hat are the result of worker no-shows.Therefore, he skills and workassignments f a worker no-showmust be assumed y one or more of the reducedcrewwho now have o performadditionaldutiesln addition to their own work assignments.Conversely, n added crew member o an exlstlngwork crew createsa disruption of an established roduction sequence foperationsand work flow; the new crew memberhas o be assimilatednto that production Uneoperation, ts related unctions,andthe sequences f operations.Qne or more of the existing rewexpend ime training he addedcrewmember, etracting rom plannedproductionefforts. Depending n the skill levelsof the established rewand the addedmember, his on-the-job raining could extendfor one or more workdays.Ihe impositionof additional earning equirementswhichalso mpacts roductionsequencing)or either a reduced r augmentedwork crew esults n: (1) a majordisruptionof an established ork low/sequence;2) an mpositionof increasedearningor asslmilatiOnof newworkers nto the work flow; (3) an overall reduction n crewwork efficiency nd productivl~, (4) lessunits of work produced;and lastly (5) lessunits of work in place mpactingprogress ercentagesttained or a given report period.

THE PHENOMENON OF VARVING CREW LEVELSThe labor productivity mpactof any reduced r augmented ork crew s what this author has abeled hephenoiaenon of vat@%cmv Zevek Ihere is an unknown corollary abor productivity mpactwhen there is a reducedwork crew due to a worker no-show,or when an existingwork crew s .augmented la the addition of a new worker.Ibis labor productivity mpact or the reducedwork crewhaving he worker no-showderives rom having one or more Of thisskilled and integratedwork crew having o learn and pet-form ot only their assigned ork item(s) and skill level(s),but also boSeassigned ork item(s) and skills previouslyperformedby the worker no-show. Theseadded earning esponsibiities nd additional

petioITMnw duties prevent the reducedwork crew rom meetingproductiongoals. Hence,productivity s diihed.Conversely,n augmentingan existingwork crewvia introduction of a new crew worker, not only is there a disruption of anestablished roductionsequence f operations ndwork flow, but also he newcrewmember as o be assimilatednto that production

line operation, ts related unctions,and the sequences f operations.Thus, one or more of the skilledand integratedwork crewwillhave o performon-the-job rainiig of this newworker n the functionsand tasks f this work crewand ts expected roductionoutput.c.2.1

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Jhe addedhMructional/trainingefforts expendedby one or more workerswithin the established ork crew detracts rom plannedWuction efforts. This reducedwork effort is reflectedn units of work produced.Again,productivity or this augmented work crewis diihed.

Ihe Specificabor productivitypenalty-add, xpressedn workhours, s in direct relationship o the amount of additional earningimposed pon either he reducedor augmented ork crew(s).The higher he craft skill levels o be earned, e, electrical,mechanical,millwright, nstrumentation,welding, etc, the higher is the numericalworkhour penaltyadd for a worker no-showor added crewmember o an established rew.

Cmverseiy, he lower the craft s!xih evels to be learned, e, labor, cement inisher, craft helper, apprentice, ebar, etc, the~her/k-ss is the numericalworkhour penalty-add or a worker no-showor addedworker to an established rew.

Over the pastdecade, he construction ndustry has discussed nd debated he followingareas:0 Can the majorityof activitiesassociated ith constructionprojectsbe equated o thoseof a production ine?0 If constructions productionoriented,what are the productivity mplications f a worker no-showon an established ork crew?Is there any corollary mpactwhen there is an addition to an established ork crew?0 What is the impacton worker learning rom reduced/augmentedork crews?0 What part in the production effort do generalcraft/craftsupervisoryevelsplay?The construction ndustry as a whole s in generalagreementwith someof the following:0 Many activitiesassociated ith constructionprojectsare analogouso that of a production ine.0 Ht s a logicalassumptionhat a worker no-&w from an established roduction ine operationwould imposeaddedor increasedhzarning n the remainingwork crewmembers.The samewould be true when here s an addition to an established ork crew.0 Craft supervision as been he basisof manystudieswith published iterature stresshrghe importanceof supervision or crewsthat are scattered r not concentrated.These ame tudies n general raft supervisors howed upervision f the individual craftsupervisor otbe of extreme mportance.

t s kking, unfortunately, s that no research asbeen diiected (at the time this technicalpaperwas prepared) o evaluate hecx&!meurroductivity mpactof varying crew evelsand fluctuatingsupervisoryevels,and:0 increasedearning mposedon the work crewsdue to fluctuations/variationsn crew evels.

distribution of the skill levels o be learnedover a period of time based n the assumed raft shill. correlationof crewworkhours ost due to undersupervision y the craft supervisor.

the additional mpactof crewworkhours ost due o undersupervision y the general raft supervisor f the various ndividual craft5qm-&or(s).

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PROJECIS SELECTED FOR EVALUATION OF VARYING CREW wBACKGROUND FOR THIS PAPER

This paperdiscussesrojectswherestudieswereaccomplishedstablishinghe numerical abor productivity mpact,expressednworkhours,of vatying crew evelsversusprojectswhereworker evelswereconstant;t is based n observations nd studiespreparedduring field assignmentsn the Middle East,Europe,and the United States. During theseassignments, specific orrelationbetweenprojects ith constantwork crew evels ersusprojectswhosework crewlevelsvaried, was noted as ollowsz

0 constantwork crew evelsversus luctuating crew evels: lhere wasa higher reliability in forecastingmonthly project progresspercentageao be accomplishedor a projectwith constantwork crew evelswhen compared o projectswith fluctuating crewlevels.0 Number of workers n a work crew (odd or even?): Basedon field counts, ailying of payroh ime sheets,imekeeper aii fieldchecks, he majority of the work crewsemployed n a projectwith constantworker evelswas ound to be composed f even-numberedworkers Conversely,he same nalysis ffected n projectswith varyingworker evelsdiilosed just the opposite-themajority of thesework crewswere composed f odd-numbered orkers.

LABOR PRODUCTIVITY BASIS FOR EVALUATION OF VARYING CREW I:EVALUATING THE NUMERICAL PRODUCTIVITY IMPACT

OF A PROJECT WITH VARYING CREW LEVELSThe followingcriteria were establishedo evaluate he numericalproductivity mpact or projectswith varyingcrew evelsstudiedand critiqued under this technicalpaper.

constant Crew Leve MjectlThere were no additions/delet~onsn established rews,and supervisoryevels emainedconstant; hesecriteria represent he

baseline used o evaluate he projectsanalyxd in this technicalpaper.Varying Crew Levels, Woricq r No-shows, and Additions to Existing Crew Level jeeta 2 and 3

When a worker wasa no-show, workhour penalty-add, arying rom 8 to 16workhoursper occurrence er projectworkday(s),was assessed. asedon the required craft skih,levelper the specificproject under evaluation, his assessmentould be increasedsubstantially nd subsequently preadover a period of time.When a worker was add&augmented to an existingwork crew,a workhour penalty-add, arying from 4 to 16 workhoursperoccurrence er project workday(s),was asses&l. Basedon the required craft skill level to be assimiWednto the established orkcrew, his assessmentould be increased ubstantially nd subsequently preadover a period of time.For workhour penalty-add(s)or other projects, evaluationswould be predicated n the required projectworker skill levels.

V* Craft Crew Supervisory Levela-+ro&ct 3Whencraft supervisor(s)evelswere dentifiedasbeingother han ug-time based n certifiedpayrolldata), he workhour penalty-add was basedon the number n the work crew imes he numberof hours that were unsupervised.

Vary@ Overdi General Craft Supervisory Leve~ject 3When the generalcraft supervisor(s)was dentifiedas beingother than full-time (based n certi8edpayroll data), he workhourpenalty-addwas basedon the number n the work crew imes he number of workhours hat craft supervisors ere unsupervised

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IIn order for the studiesbeiig presented o have somedegreeof reliability, the projectsselectedhad to have estabhsbed ndOpmting Specifk! project controlssystems. liheseestablished ro ject controlssystems ncOmfNL%Wd:0 a prOgRs measurementeporting systemwherequantitiesof work-in-placewere evaluated n a set time perk%0 an existing eporting system roviding number of daily generaland craft supervisors nd classification f workers;and0 a sekxtive reporting SJrstemdentiQing and tallying repetitive fogowon workhour operations. Learning curve-s would bebasedon t&se WfoUow-onork items.

To set the stage or the studies o follow and to outline the conceptof learning, e, the productivity mpactof a worker no-showor a crew augmentation, be readersare requested o recall vivid Desert Storm video footagedepictingvarious production linesequencing perationsof a 155MM gun crew n action.hadem may red in their minds eye the various sequenceseadingup to the Bring of a 155 MM weapon. Each member(worker) of that crew had a specificassignment item of work) to accomplish he end result (production flow+fire a shelf(productivity). Eachmemberwasdependent pon the actionsof others training) o performat their spfxitic individual responsibility(skill level). The higher he coordinationof this team (craft earningcurve), he higher he production shells ired per mhutte),withperformance eing equated o number of shells alling on a target (quantitiesof work in place).Keepiagwith this same cenario, hould one or more members f the 155MM gun crewexperience casualty r injury (workerno-show), he composition f the trained and established rewwasdisrupted, mpactingboth the crewskills/make-up nd productionfIm, resulting n decreased roduction/outputas an endamsequence. Ibe military plan for this event,via extensive raining, was oinstructothers n the gun crew o assume dditionalduties. Thus, n the eventof a military operation,ndiidual combatcrewefficiencywasmahrtained o a known or predictableefficiency evel (shells alling on target), basedon assumednjury/casualtyevels.Some eadeps f this technicalpapermight not accept he exampleistedaboveequatinga craft earningcurveand he sequentialactionsof a 155MM DesertStormgun crew o production elatedsystems r functionsof a construction rew. Conversely,here are,undoubtedly,an equal number of readerswho can quite easilyequateconstructionactivities o combat operations! Interestinglyenough, he constructionndustry hasadopted ertainmilitary argon nto its daily operations, g,demobiition, mobilization, tagingareas, ogisticalsupport,etc.

The iWz&nc ~LT$E&, ith constantworker/crew evels,was a remote ocalewithin the Arabian Peninsula equiring a workerconstruction amp. Thus, the samecrew members nd skill mix were allocate&toa specificwork activity,which conthxreduntil thework wascompleted.

fnstahationof trays or stripper and contactor essels, ne each or a three-trainmodule.The stripper nternal tray requirementswere 11,290 quare eet (1037 V?); the contactoenternal tray requirementswere lO,725 quare eet (985 MI*).

Iproject ontrol requirements oe his analysis ere met. The installationcontractorassignedwo separate nd identSiableworkcrews one eachper stripper and contactoe).Various photographs f work activitieswere taken.

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Analysis Resultr3Installationof the stripperand contractor nternal rayswascompletedor the three-traincomplex.The tallied workhours or theinitial stripper and contactor esselsn train #l werecomparedo,the ollowan workhour efforts or the stripperand contactor esselslntralns#2and#3.This comparison evealed reductionof total workhours or the follow-onstripperand contactor esselsn trains #2 and #3 andrepresentsworker learning on repetitive operations.

Analyaia conclusionsA reduction in workhours on repetitive followon work effor ts derives rom the implementationof a learning curve by theinstallationwork crew(s). Learning curve mprovements xpressed s a percentageor eachstripper and contactor ollow-onvesselswereas follows:

SWper tlmtactor It was he conclusion f this work sampling ffort and hosestudieswhich ollowed seeTrain#l Base Other Data below) that projectshaving constantwork crew levels could confidentlyTrain#2 91.5 % 98.8 %

expect earningcurves o be demonstrated n repetitivework operations.Train #3 87.4 %* 81.1 %* Other Data*compared o workhours Wed for train#2 There were some70 other selectedwork samples equipment oundations,pipewayfoundations, ettingof vessels, rectionof stainless teel,erectionof pipe spools, in fanstructures, tc) on repetitiveoperations hat wereundertakenon this particular hree-train moduleconstructionproject. Thesework studysampleseconfirmed hat total workhours or follow-onoperationsn trains #2,and #3 were consistentlyess han the original nstallation. Seventy eparateearningcurveswere derived rom thesework samples.

PROJECT )RVALUATINGA PROJECTWITII PLUCTUATINGWORKER/CREW LRVRLSProjec t 2, with fluctuating crew evels,wassituated n the central United States.Subcontractorabor requirementswere o besecured rom the local unions (closedshop). There wasno requirement or a worker constructioncamp.

Repetitive Operation SelectedField erection of 46 steel storage anks of variousstorage apacities nd confIgurations nder terms of a subcontract.Basisof AnalysisProjectcontrol requirements or this analysiiwere met. In addition,a projectweather og listing rain showers nd days ost torain wasalso maintained y the constructionmanager.lb0 electronic preadsheetsereprepared.One, o calculatemonthly ncremental rogress ercentagesased n the construclionmanagersmonthlyevaluationon a tank-by-tank ercent omplete.The other spreadsheet asemployedo track dailyvariationswithinthe established rew composition. The productivity mpact of such crewvariationswas basedon the details established nder thesectionentitled Labor Productivity Basis or Evaluationof Varying Crew Levels.

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k3rmnpb lLa@mnueThe completed project ouerran theplannedSubcoatractorsorkhour budgetby33.6% as showa n figure 1). Figure 1 dam

KlOt diX.kJse learningcurve or the project,eg, here wasno reductionof workhours orfollow-onof in-place ankage onnages erreporting month.

The subcontractor% planned totalworkhoun omittedadditionalworkhours orratn shower remobiitioa, ltxt rain days,and holiday remobiitions when preparingthe site workhourS or the project. Theseomimioashad beea highlighted by the con-struction maaagefs review of thesubcoatractops roposedSiteworkhours.!Furtbermore,he subcontractorsman-agement taff ailed o seea linkagebetweenthe number of tanks to be erected for agivenmonth and the need or an eveunoun-bn of operatingengineetx nd craft supervi-~ors o support and supervise ank erection

Projected Work Howo Al 100% Canpletion

ASOWOJFMAMJJASOWDJFMAl Camplotion Work How Leveelo

0 s/c EwDGET W# HOURS 0. ACT1 TANK WOR#HDllRS A FCSTD ti lfRS/MXdTHv M FCSTD WHRS cNX3%

operations; ield studiesand observations ndertakenduring the tankageerectionphases oted erectioncrewswaiting for mater%,automaticwelding machines o be rained,and other delayS ecausehe ratio of craft supervi.sorSnd operatingengineer to erecttankage hroughout he projectwasnot an even number (See able 1).

M&s in work 6Report month Asupemn 5Operatingengineers 5Boiler makers 20Welders 12crewotals

EWios/tanksn worksupervisors@mating engineersRatio boiler makers/QEWelders/tanks

37

1.21.24.02.07.4

13 11 13 17 19 3Q 210 D 9 ibl 9 s .I6 6 6 6 6 7 64 5 6 9 13 19 1011 26 26 33 51 105 6715 15 19 37 49 92 3830 46 51 79 113 216 115VARIOU8 RATfQS A8 IxxED FOR THE OIv3R.ATfQNSSH0wPd

2.2 1.8 2.2 2.8 3.2 4.3 3.53.3 22 2.2 1.9 1.5 1.6 2.12.8 5.2 4.3 3.7 3.9 5.5 6.71.2 1.4 1.5 2.2 2.6 3.1 1.85.0 7.7 8.5 13.2 18.8 3Q.9 19.2

Site craft supervisoryevelswereeSsentia$ onstant rom project nception, he craft superwiSorsereprecluded orn adequatelysupervlsiig their geographically cattered ork for&q and thus were unable o keeperectioacrewS uppliedwith material(s) tat&plats, welding o&), repair of automaticweldiig machineS,tc, particularly n the tatter stags of the projectwhen Some 9:29 ankshad to be erectedunder a compressedime schedule.

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TANKAGE WORK HOURSTUDYLEARNING CURVE the progressmeasurement ase when thetankage ubcontractor reparedhis progressmeasurement aseline. These mobiition

effortswere, herefore,not considered henthe constructionmanager tatused he tank-agework.A theoretical tankage workhour study,taking into consideration even-numbered/ I ratios for operating engineers ersus anksunderconstruction monthly)withsupporting100 - boilermakerrades,weldersandealistic raftsupervisor(s) ratios, was prepared. The

so- study resultsof this theoretical eveledworkcrew were graphed see igure 2) and com-0 I I I I I I I I I

A S 0 N DJ F M A M J J A,S 0 N 0 J F Mpared o figure 1. Had this theoreticalwork

Time Frame Aa Noted crew plan, basedon even-numberedwork0 S/C BUDGET WK HOURS 0 ACTL TANK WDRKHDURS A FCSTO WK HRS/MDNTH crews, een ollowed,a learningcurvewould

v EV FCSTO WHRS 0100% have been engendered y the vurious ereution crews nd he penalty-add orkhours orFigureBox the varying crew levels would have beenreducedconsiderably.

Workhoursexpended o mobilize ankagematerials (base plates, exterior rings, androof structures, tc) had not been ncluded n

Additional labor productivityconsequenceaereanalyzed.They wereschedule ompression f tanks, ain showerdelays, olidayremobiition, and rain day remobilizations.Theseare not a portion of this varyingcrew evel abor productivitystudyand are, here-fore, excluded.Almlydsconelusions

Rased n the evaluationcriteria established nd a day-by-day nalysiiof the work crews, he following abor productivity mpactpercentagesor varying crew evelswere calculated:Rain day remobilization excludedHoliday remobilization excludedRain showerdelays excluded 1Adds/deleteso work crews 14.13% ,Supervisory hanges 7.50%Schedule ompression f tanks CXChdedThe lineal feet of automaticand manualweldingper tank, including the weight of the depositedweld metal,was not madea

considerationn the progressmeasurement ase or each ank erected. This prevented more realisticevaluationof actualwork inplace or each ndividual tank and introduceda major biason the plus sidewhen calctuating ercentage f work completed.

PROJECT+EVALUATINGA PROJECTWITH PL.UCTUATING UPERYISORY ND WORKER/CREW EVELS,Project 3, with fluctuating craft supetvisotyand worker crew evels,was ocated n the central United States.The labor productivityanalysisor Project3 is unique n that it involveda specialty ubcontractor orkingwithin the battery imitsof an ongoingoperatingplant. This particular subcontractor ad bid on, and received, ontracts or the performance f his specialtysubcontracts kills on three ongoingprojects or the sameowner,all to be accomplished t the same ite. All three projectswere at

least partially under concurrentconstruction n variousgeographicalocationswithin the sameoperatingplant. Subcontractoraborrequirementswere to be secured rom the local unions (closed hop). There wasno requirement or a worker ConstructiOnamp.0.

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No repetitiveoperationswere selected.Aualysii performedafter work on contractedwork scopehad been completed.

Evaluationof a majorsubcontractors ii for lossof labor productivitywasmade. Project ontrol requirementsor this ax.@%&measurement ystemwas basedon a scheduleof dollar values (set up in the biddingand utilized for progress aymentso the subcoatractor.. he schedule f valuesdocumentdid not provide quantitiesofe installed or many ine items,aad thus, did not equatepercentages f work in place.Pvo electronic preadsheets ere prepared. One calculatedmonthly ncremental rogress ercentages asedon the enginc&sestimate nd workhours or the contractedwork scope. The second preadsheet asutilized to track daii variationswithincomposition, sing he data providedby the subcontractor ertifiedpayroU ecords. The productivity mpact fvariationswasbased n the detailsestablished nder the sections ntitled abor productivitybasii for evaluationof .varyingand he phenomenon f varyingcrew evels. Actual workhoursexpended ereextracted rom certifiedpayroU ocuments.The certitied payrolldata enabled detailedevaluationof the work crew(s)and supervisoryevelson a day-by-day asii. For the

work scopeunder investigation, he certifiedpayroll data disclosed ssigned orkers, craft supervisors, ad geaeralcraftevelswere not working on a full-time basii.Correspondencerom the constructionmanagers taff to the owner documented hat the subcontractorswork crews andupervisory taff craft and general upervisoryevels)werebeingshiftedor rotated rom contract o contract. Ibis rotation,f work crewsand supetvisory taff,was, n manycases, ocumentedo occur on a daii basii. Shiftiig work crewsandwere he subjectof correspondenceirected o the subcontractors anagement nd noted n minutesof meetings.The spreadsheetatawere plotted asa relationship o the optimalworkhours hat could havebeenexpended n contractedworkdaily basishad the original work crewsaad supervision ssigned orked ull-time on a singleproject,versus he actual hours thater the certified payroll data.To better evaluate he graphicdata generated,10 randomlyselectedmonths rom the overall timeframeof 30 months weremonth selected, day-by-day orkhour analysiswasundertaken, o the level of detail which listed the individualmemberby nameand classification, nd the total hours worked by the individual on that particular day.

Based n the evaluated ertitiedpayroU orkerdatabase nd he criteria istedunder the sections ntitled abor productivitybasisof vatying crew evelsand the phenomenon f varyingcrew evels, he workhour abor productivity penalty-add ue tocrew evelsand craft supervisionwascalculated o be 31%.This 31% loss of labor productivity was evaluated o be a direct consequence f a business ecisionby the subcontractorso shift, dilute, and rotate work crewsand supportingsupervisory taff from contract o contract

This studywasutilized during negotiations valuating he subcontractorslaim or lossof labor productivityand becamehe basis

The literature searchundertakenat the time this paperwas prepared ndicates hat the construction ndustry and supportingia tudies ecognize he importanceof supervisory taff (eg, generaland craft supervisors) nd a relationship o the overallthe constructionwork crews, nd mportance f the craft supervisor is-a-visndividual crewproductivity. There wereand titles eelative o the aforementioned.

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Ibis same iterature search, owever, upported he contentionof many n the construction ndustry hat neither he constructionindustry nor academia asyet to direct any research tudies, nd hence,publishedarticles, o the areaof productivity repercussionsfrom varying crew evels,eg, reducedwork crewscomposed f worker no-shows r augmeatedwork crews.However,a literature search n the areaof learningcurvesdid showvariousstudieshad beenperformeddemonstrating xpected

consequences hen production ine crewswere either increased r decreased.1)CONCLUSIONS

Constructions productionoriented,with both progress ad performance quatedon total quantitiesof work n place.Therefore,any disruption to an established ork flow or productionsequence ill result in a decreasen labor productivity/crew fficiency.Varying crew evels,eg, any work crewcreatedasa result of a worker no-showor one that hasbeenaugmented ia introductionof a new or addedworker, have the following abor productivityconsequences:

l disruption of an established roduction work flow/ sequence.0 impositionof learning requirements or either the reducedor augmentedwork crews.0 reducedoverall crew efficiencyand productivity.0 lessunits of work produced n a given time period.0 lesspercentage f progress ccomplishedor a given report period.

Varying levelsof ,general raft supervision nd/orcraft supervisors ill exacerbate ll of the labor productivityareasenumeratedabove.This paper has diissed projectswhere studieswere accomplished n the labor prcductivity effectsof varying crew evelsandoutlined he method/concept mployed or these tudies.Utilizing the concepts f this paper,augmented ith on-site tudies erformedon a project,a definitive/evaluative umericalworkhour productivitypenalty-add an be established.Wherepossible, nstruction managementhouldstresshe creationof even-numbered,onstantwork crewsevels.This will allowlearning curves or repetitive constructionoperations; dd-numbered, aryingwork crewswill not readii exhibit learningcurves.Wherepossible, eneral ontractorand subcontractormanagementtaffshould nvestigate arious ncentiveprograms or a givenproject by which labor turnover (worker no-shows)will be reduced o zero.

REFERENCE&1. Smith,J. 1989. earuing Curve or Cost ~.ontrol. nstitute of JndustrialEngineers. orcross,Georgia: ndustrial Engineering ndManagementPress.

Donald J. Cass,CCECassand Associates321 S. Hobart Bhrd. #207Lus Angeles,CA 90020