Presentation on theme: "CE 403 Construction Methodology"— Presentation transcript:
1CE 403 Construction Methodology Construction Productivity
2Measures of Construction Performance Construction performance involves all aspects of the construction process.It is a broad inclusive term that includes four elements:SafetyTimelinessQualityProductivityConstruction Methodology
3WORK INJURY AND ILLNESS RATES Incidence rates expressed as number of cases per year or days per 100 full-time employees or 200,000 employee hours per yearIncidence Rate = (# of cases or days per year x 200,000)/Total employee hours per yearCan be computed for each category of cases or days.3/31/2017
4Construction Performance: Timeliness Interpreted both as “on schedule” and “everything is on hand when needed”Construction Methodology
5Construction Performance: Quality Means that the facility and all its elements meet the specification requirementsOwner’s Perspective: Test performancesCraft (Field) Perspective: ReworkConstruction Methodology
6CORRECTION: Field Productivity Actual productivity determines whether or not the project will be completed within the cost budget and time scheduleLabor Productivity = Production Output/WorkhoursFactor Productivity = Production Output/Total CostProductivity Factor = BCWP/ACWPDirect Work Rates (i.e. tool time or wrench time)Construction Methodology
7Factors Affecting Labor Productivity Construction Methodology
9Factors that have an adverse effect on productivity Overtime and/or fatigueErrors and omissions in plans and specificationsMultitude of change ordersDesign complexityDesign completenessStacking of tradesDilution of supervisionReassignment of manpower from task to taskMaterial locationAbove ground levelAbove floor levelAdverse temperature or weatherInadequate lightingConstruction Methodology
10CORRECTION: Field Productivity Actual productivity determines whether or not the project will be completed within the cost budget and time scheduleLabor Productivity = Production Output/WorkhoursFactor Productivity = Production Output/Total CostProductivity Factor = BCWP/ACWPDirect Work Rates (i.e. tool time or wrench time)Construction Methodology
15What causes change orders…at least in Highway Work. Statistical Analysis of Change Order Data610 Projects246 New Construction364 Maintenance ProjectsProjects Completed between 2005 and 2008What causes change orders…at least in Highway Work.Reason CodeFrequencyAvg. CO Amt. ($)Avg. Percent Change in Original Contract Amt.Asphalt Lot Pay Adjustment188$7,699.930.79%Fuel & Asphalt Adjustment218$82,336.077.05%Contract Omission243$57,410.904.53%Utility Issue60$35,428.113.16%Contract Item Overrun227$104,857.536.73%Geotechnical Issue71$90,777.413.02%Owner Induced Enhancement186$88,297.137.80%Environmental Issue20$19,737.720.47%F-Value4.02513.024P-Value0.000KYSPR
18Factors that have an adverse effect on productivity Overtime and/or fatigueErrors and omissions in plans and specificationsMultitude of change ordersDesign complexityDesign completenessStacking of tradesDilution of supervisionReassignment of manpower from task to taskMaterial locationAbove ground levelAbove floor levelAdverse temperature or weatherInadequate lightingConstruction Methodology
19Factors that have an adverse effect on productivity Regulations of various typesHigh absenteeismHigh turnoverMaterial shortagesHigh accident ratesJurisdictional disputesWork rules and restrictive work practicesAvailability of skilled laborAttitude of the workforceCrew size and compositionTimeliness of decisionsConstruction Methodology
20Construction Inflation Freedom Tower has unusual torque design.Designers say the world's tallest building, Freedom Tower, will include a wind farm, solar panels and advanced, energy-efficient technology, and will become an icon of environmentally friendly architecture.Empire State BuildingCosts: $40,498,900 (1931 Dollars)$559,321,201 (2006 Dollars CPI Adjusted)Freedom TowerProposed Costs: $1.6 to 2.1 Billion (2006 Dollars)Construction Methodology
22Why Train? What are the Benefits? Data from winners and finalists of the Workforce Development Excellence Award (Houston Business Roundtable)OSHA Recordable Injuries down 67%, First Aids down 90%Productivity up 10 to 24%Rework down 50 to 70%Turnover down 32 to 43%Unexcused Absences down 59%Worker Morale and Company Loyalty is upConstruction Methodology
23Company A: Absenteeism and Turnover Data The study found that workers receiving training had a lower turnover and absenteeism rates than workers without training.Workers without TrainingCompany Certified WorkersWorker Receiving TrainingTurnover Rate6.51%3.39%0.63%Absenteeism Rate7.28%0.27%2.51%Construction Methodology
24Company B: Productivity Data A declining performance factor indicates productivity improvementshow F-value and R-square in the bottom right hand corner. Emphasis that productivity could be measured.Speaker: PaulFinally, RT-231 studied the experience of Company B that was engaged on a construction maintenance project in which the owner actively promoted both written and performance certifications of their craft workers in accordance with the NCCER certified plus designation. Over a 12-month time period, Company B measured the percentage of its craft workers that had achieved certified plus and the corresponding productivity performance factor that was experienced on the project. In this case, a declining performance factors indicates an improvement in productivity. Although this case involved a relatively limited sample size, the figure shows that as the percentage of certified plus craft workers increased, the project’s productivity performance factor improved as well.When examining this case, it was clear that the owner’s involvement in the craft training certainly helped make a difference. With that, it is my pleasure to introduce an owner’s representative from our team, Mr. Joby Frame of the Southern Company, who will present the business case for craft training on a typical industrial project.Company B Productivity Performance Factor vs. Percentage of Certified PlusTM Craft WorkersR2=0.39F value =6.478P value = 0.029TM Certified Plus is trademarked by NCCERConstruction Methodology
25Factors that have an adverse effect on productivity Regulations of various typesHigh absenteeismHigh turnoverMaterial shortagesHigh accident ratesJurisdictional disputesWork rules and restrictive work practicesAvailability of skilled laborAttitude of the workforceCrew size and compositionTimeliness of decisionsConstruction Methodology
26Factors that have an adverse effect on productivity Impractical QA/QC tolerancesUncontrolled breaksTime of day and day of weekInadequate temporary facilities: parking, change rooms, restrooms, etc.Construction Methodology
28Preconstruction concepts which promote productivity Improve site accessEarly procurement of materialsIdentification of materials in known locationsPre-planned proceduresPre-assembled componentsProper sequence of workAdequate construction equipmentObtain necessary small toolsSecure licenses, permits and inspectionsLevel manpowerConstruction Methodology
30Four Methods for Determining Cost and Time Allotments Horseback, or “Ballpark,” EstimatesEstimates by Qualified ExpertsHistorical or Statistical EstimatesEstimating by Computed, or Engineered, StandardsConstruction Methodology
31Method 1: Horseback, or “Ballpark,” Estimates Draw on knowledge of similar projects done in the pastApply adjustments for such factors as inflation, relative costs between geographical areasConsidered approximateE.g. X dollars per lineal foot of floor areaConstruction Methodology
32Method 2: Estimates by Qualified Experts Relies on personal knowledge and skill of an expertRelies on the experience of an individual and their knowledge of the conditions under which the task will be doneCommon practice is to involve field personnel – Superintendents, foreman, lead-manConstruction Methodology
33Method 3: Historical or Statistical Estimates Relies on records of previous projects to determine cost and time required for appropriate:IndividualsCrewsMachinesOther conditionsFor those without in-house information, books and other publications give unit performance rates for more common construction operations – Eg. Means, Richardson Process Plant Estimating Standards, Dodge Unit Cost BooksConstruction Methodology
36Method 4: Estimating by Computed, or Engineered, Standards Computed standards utilized measured values of time required for trained individuals to carry out basic movementsPro: Can be very accurateCon: Very time consuming for the plannerConstruction Methodology
39Current Methods for Assessing Work-Face Productivity Work-face activities often get little attentionMost construction analyses involve examining project cost and schedule performance.A project’s success can be made or ruined at the workface.Two categories of workforce assessment methodsInformalFormalConstruction Methodology
40Current Methods for Assessing Work-Face Productivity Informal:All construction managers will tell you they can judge how well a work-face task is going by merely watching for a short period of time.However, they may not be asking themselves such questions as:“Are materials and tools available and suitable?”“Is the work procedure and its sequencing the most efficient?”“Have tasks been assigned among members of a crew that best uses available skills and keep all hands busy?”Construction Methodology
41Current Methods for Assessing Work-Face Productivity Formal:Most common assessment methods: slippages in schedule and cost overruns.Problems:Can be based on after-the-fact informationMay be inaccurate (not recorded accurately)Errors in codingFalsified to hide slippageConstruction Methodology
42Current Methods for Assessing Work-Face Productivity Other formal methods:Time studies using photographic or video methodsQuestionnaires and InterviewsEg. Foreman Delay SurveysWork SamplingConstruction Methodology
44Work SamplingConsists of observing and classifying a small percentage of a project’s labor activityInvolves making and analyzing the results of field observations to determine what individual workers are doing at specific instants in time.Most of the data is recorded in the following Categories:Productive WorkDirect WorkToolsMaterialsInformationNon-ProductivePersonalTravelWaitingConstruction Methodology
45Work Sampling Direct Work (25-65%): Activities directly involved in the actual process of putting together or adding to a unit being constructedIncludes necessary disassembly of a unit that must be modified and movements essential to the process where the work is being doneE.g. painting a wall, placing bricks, nailing boards to a wall, hauling material from an excavation, threading pipe, mixing mortar, cutting boards before nailing.Construction Methodology
46Work Sampling Support Work: Preparatory Work or Instructions Receiving instructionsReceiving drawingsUsing telephones or radios for work related reasonsDiscussing material, tool, or equipment needsTools and EquipmentLocating a tool in a gangbox and transporting it to the task areasObtaining and transporting slides, shackles or similar tools equipmentPutting on and adjusting personal protection equipment (PPE)Material HandlingSupporting crafts transporting bulk materials (Operators and Teamsters are Direct Work)Construction Methodology
47Work SamplingDelays:Doing something that is in no way necessary to complete the job.WaitingTravel (empty handed (toolbelts), walking to and from work areas)Personal (rest periods outside break times, adjusting personal clothing, rest room or water breaks outside break time).Construction Methodology
48Activity Categories Steve Tools and EquipmentMaterial HandlingTravelDirect WorkPersonal TimePreparatory WorkWaitingSteveTo make you more familiar with the activity analysis, let’s review some typical categories that our team used during last year’s field trials.Direct Work is the category.Examples include electricians wiring in an electrical outlet
49Activity Categories Steve Tools and EquipmentMaterial HandlingTravelDirect WorkPersonal TimePreparatory WorkWaitingStevePreparatory Work also includes discussions to explain or plan the task at the work location. These discussions can take place between craft workers or between supervisors and craft workers.
50Activity Categories Steve Tools and EquipmentMaterial HandlingTravelDirect WorkPersonal TimePreparatory WorkWaitingSteveAnother category is Tools and Equipment. This is an example of a craft person operating a man lift.
51Activity Categories Steve Material Handling is the next category. Tools and EquipmentMaterial HandlingTravelDirect WorkPersonal TimePreparatory WorkWaitingSteveMaterial Handling is the next category.The difference between equipment and material is material goes into what we’re building and we use equipment to build it.Here we have a craft worker a couple of structural steel pieces.
52Activity Categories Steve The next category is Waiting . Direct WorkPreparatory WorkTools and EquipmentMaterial HandlingWaitingTravelPersonal TimeSteveThe next category is Waiting .Examples include waiting to gain access to work area or for another craft to finish work.
53Activity Categories Steve Travel is the next category. Tools and EquipmentMaterial HandlingTravelDirect WorkPersonal TimePreparatory WorkWaitingSteveTravel is the next category.Travel includes craft walking with their normal small tools, like a carpenter with his tool belt.
54Activity Categories Steve Finally, the last category is Personal. Tools and EquipmentMaterial HandlingTravelDirect WorkPersonal TimePreparatory WorkWaitingSteveFinally, the last category is Personal.I am now going to turn it over to Shannon Hopkins from Tennessee Eastman.
55Work SamplingThe rating should be taken at the first instant of observation. Don’t anticipate a person’s actionCounts should not begin until at least ½ hour after start time and ½ hour before quitting or lunch time.Must be an equal likelihood of observing every worker.Sample shall contain no less than 384 observationsBasic characteristics of the work situation must remain the same.Construction Methodology
59Work Sampling 100% Direct Work Want to maximize SupportDelayWant to maximizeTotal Construction Time0%25%50%100%Break down into subcategories for class project.Construction Methodology
60Case Study Idaho Falls Nuclear Decommissioning Project. Treating nuclear, sodium-bearing waste from a liquid to a solid state using a steam reforming processPrimary Trades: Piping, Concrete, and InstrumentationInitial Budget: $84MFinal Budget: $176MConstruction Methodology
68 Project Activity Category Wood River Project A Project B Project C ProjectActivity CategoryWood RiverProject AProject BProject CProject DProject EAverageIdaho FallsDirect Work31%28%42%30%27%20% Prep Work13%16%8%11%12% 18%Tools/Equip7%19% 9%Mat'l Hand4%2%5%9% 3%Waiting15%20%14% 19%Travel24%23%17%18% 22%Personal6%Construction Methodology
69Work Sampling Example: Edmonton Project Construction Methodology
70Work Sampling Limitations Work Sampling provides a measure of worker efficiencyWorker efficiency can only be considered an indirect measure of productivity.Reviewed with great suspicion by craftsmen and foremenConstruction Methodology
75Percent Direct Work by Crafts* Pipefitters/Welders 28%Boilermakers 27%Electrical Workers 28%Laborers %Carpenters 42%Insulators %Operating Engineers 39%Ironworkers 31%Millwrights %* “Productivity in Power Plant Construction,” Marjatta Strandell, 1976 AACE Transactions, pp
76Source: Oglesby, C. , Parker, H. , and Howell, P Source: Oglesby, C., Parker, H., and Howell, P. (1989) Productivity Improvement in Construction. McGraw-Hill, New York, New York.Construction Methodology