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CE 403 Construction Methodology

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Presentation on theme: "CE 403 Construction Methodology"— Presentation transcript:

1 CE 403 Construction Methodology
Construction Productivity

2 Measures of Construction Performance
Construction performance involves all aspects of the construction process. It is a broad inclusive term that includes four elements: Safety Timeliness Quality Productivity Construction Methodology

3 WORK 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 year Incidence Rate = (# of cases or days per year x 200,000)/Total employee hours per year Can be computed for each category of cases or days. 3/31/2017

4 Construction Performance: Timeliness
Interpreted both as “on schedule” and “everything is on hand when needed” Construction Methodology

5 Construction Performance: Quality
Means that the facility and all its elements meet the specification requirements Owner’s Perspective: Test performances Craft (Field) Perspective: Rework Construction Methodology

6 CORRECTION: Field Productivity
Actual productivity determines whether or not the project will be completed within the cost budget and time schedule Labor Productivity = Production Output/Workhours Factor Productivity = Production Output/Total Cost Productivity Factor = BCWP/ACWP Direct Work Rates (i.e. tool time or wrench time) Construction Methodology

7 Factors Affecting Labor Productivity
Construction Methodology

8 Construction Methodology

9 Factors that have an adverse effect on productivity
Overtime and/or fatigue Errors and omissions in plans and specifications Multitude of change orders Design complexity Design completeness Stacking of trades Dilution of supervision Reassignment of manpower from task to task Material location Above ground level Above floor level Adverse temperature or weather Inadequate lighting Construction Methodology

10 CORRECTION: Field Productivity
Actual productivity determines whether or not the project will be completed within the cost budget and time schedule Labor Productivity = Production Output/Workhours Factor Productivity = Production Output/Total Cost Productivity Factor = BCWP/ACWP Direct Work Rates (i.e. tool time or wrench time) Construction Methodology

11 Construction Methodology

12 Construction Methodology

13 Construction Methodology

14 Construction Methodology

15 What causes change orders…at least in Highway Work.
Statistical Analysis of Change Order Data 610 Projects 246 New Construction 364 Maintenance Projects Projects Completed between 2005 and 2008 What causes change orders…at least in Highway Work. Reason Code Frequency Avg. CO Amt. ($) Avg. Percent Change in Original Contract Amt. Asphalt Lot Pay Adjustment 188 $7,699.93 0.79% Fuel & Asphalt Adjustment 218 $82,336.07 7.05% Contract Omission 243 $57,410.90 4.53% Utility Issue 60 $35,428.11 3.16% Contract Item Overrun 227 $104,857.53 6.73% Geotechnical Issue 71 $90,777.41 3.02% Owner Induced Enhancement 186 $88,297.13 7.80% Environmental Issue 20 $19,737.72 0.47% F-Value 4.025 13.024 P-Value 0.000 KYSPR

16 Construction Methodology

17 Construction Methodology

18 Factors that have an adverse effect on productivity
Overtime and/or fatigue Errors and omissions in plans and specifications Multitude of change orders Design complexity Design completeness Stacking of trades Dilution of supervision Reassignment of manpower from task to task Material location Above ground level Above floor level Adverse temperature or weather Inadequate lighting Construction Methodology

19 Factors that have an adverse effect on productivity
Regulations of various types High absenteeism High turnover Material shortages High accident rates Jurisdictional disputes Work rules and restrictive work practices Availability of skilled labor Attitude of the workforce Crew size and composition Timeliness of decisions Construction Methodology

20 Construction 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 Building Costs: $40,498,900 (1931 Dollars) $559,321,201 (2006 Dollars CPI Adjusted) Freedom Tower Proposed Costs: $1.6 to 2.1 Billion (2006 Dollars) Construction Methodology

21 Construction Methodology

22 Why 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 up Construction Methodology

23 Company 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 Training Company Certified Workers Worker Receiving Training Turnover Rate 6.51% 3.39% 0.63% Absenteeism Rate 7.28% 0.27% 2.51% Construction Methodology

24 Company B: Productivity Data
A declining performance factor indicates productivity improvement show F-value and R-square in the bottom right hand corner. Emphasis that productivity could be measured. Speaker: Paul Finally, 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 Workers R2=0.39 F value =6.478 P value = 0.029 TM Certified Plus is trademarked by NCCER Construction Methodology

25 Factors that have an adverse effect on productivity
Regulations of various types High absenteeism High turnover Material shortages High accident rates Jurisdictional disputes Work rules and restrictive work practices Availability of skilled labor Attitude of the workforce Crew size and composition Timeliness of decisions Construction Methodology

26 Factors that have an adverse effect on productivity
Impractical QA/QC tolerances Uncontrolled breaks Time of day and day of week Inadequate temporary facilities: parking, change rooms, restrooms, etc. Construction Methodology

27 Construction Methodology

28 Preconstruction concepts which promote productivity
Improve site access Early procurement of materials Identification of materials in known locations Pre-planned procedures Pre-assembled components Proper sequence of work Adequate construction equipment Obtain necessary small tools Secure licenses, permits and inspections Level manpower Construction Methodology

29 Engineering concepts which promote productivity
Timely information Simplified details Practical tolerances Avoid interferences Minimize changes Allow prefabrication Construction Methodology

30 Four Methods for Determining Cost and Time Allotments
Horseback, or “Ballpark,” Estimates Estimates by Qualified Experts Historical or Statistical Estimates Estimating by Computed, or Engineered, Standards Construction Methodology

31 Method 1: Horseback, or “Ballpark,” Estimates
Draw on knowledge of similar projects done in the past Apply adjustments for such factors as inflation, relative costs between geographical areas Considered approximate E.g. X dollars per lineal foot of floor area Construction Methodology

32 Method 2: Estimates by Qualified Experts
Relies on personal knowledge and skill of an expert Relies on the experience of an individual and their knowledge of the conditions under which the task will be done Common practice is to involve field personnel – Superintendents, foreman, lead-man Construction Methodology

33 Method 3: Historical or Statistical Estimates
Relies on records of previous projects to determine cost and time required for appropriate: Individuals Crews Machines Other conditions For 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 Books Construction Methodology

34 Construction Methodology

35 Construction Methodology

36 Method 4: Estimating by Computed, or Engineered, Standards
Computed standards utilized measured values of time required for trained individuals to carry out basic movements Pro: Can be very accurate Con: Very time consuming for the planner Construction Methodology

37 Construction Methodology

38 Construction Methodology

39 Current Methods for Assessing Work-Face Productivity
Work-face activities often get little attention Most 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 methods Informal Formal Construction Methodology

40 Current 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

41 Current 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 information May be inaccurate (not recorded accurately) Errors in coding Falsified to hide slippage Construction Methodology

42 Current Methods for Assessing Work-Face Productivity
Other formal methods: Time studies using photographic or video methods Questionnaires and Interviews Eg. Foreman Delay Surveys Work Sampling Construction Methodology

43 Construction Methodology

44 Work Sampling Consists of observing and classifying a small percentage of a project’s labor activity Involves 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 Work Direct Work Tools Materials Information Non-Productive Personal Travel Waiting Construction Methodology

45 Work Sampling Direct Work (25-65%):
Activities directly involved in the actual process of putting together or adding to a unit being constructed Includes necessary disassembly of a unit that must be modified and movements essential to the process where the work is being done E.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

46 Work Sampling Support Work: Preparatory Work or Instructions
Receiving instructions Receiving drawings Using telephones or radios for work related reasons Discussing material, tool, or equipment needs Tools and Equipment Locating a tool in a gangbox and transporting it to the task areas Obtaining and transporting slides, shackles or similar tools equipment Putting on and adjusting personal protection equipment (PPE) Material Handling Supporting crafts transporting bulk materials (Operators and Teamsters are Direct Work) Construction Methodology

47 Work Sampling Delays: Doing something that is in no way necessary to complete the job. Waiting Travel (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

48 Activity Categories Steve
Tools and Equipment Material Handling Travel Direct Work Personal Time Preparatory Work Waiting Steve To 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

49 Activity Categories Steve
Tools and Equipment Material Handling Travel Direct Work Personal Time Preparatory Work Waiting Steve Preparatory 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.

50 Activity Categories Steve
Tools and Equipment Material Handling Travel Direct Work Personal Time Preparatory Work Waiting Steve Another category is Tools and Equipment. This is an example of a craft person operating a man lift.

51 Activity Categories Steve Material Handling is the next category.
Tools and Equipment Material Handling Travel Direct Work Personal Time Preparatory Work Waiting Steve Material 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.

52 Activity Categories Steve The next category is Waiting .
Direct Work Preparatory Work Tools and Equipment Material Handling Waiting Travel Personal Time Steve The next category is Waiting . Examples include waiting to gain access to work area or for another craft to finish work.

53 Activity Categories Steve Travel is the next category.
Tools and Equipment Material Handling Travel Direct Work Personal Time Preparatory Work Waiting Steve Travel is the next category. Travel includes craft walking with their normal small tools, like a carpenter with his tool belt.

54 Activity Categories Steve Finally, the last category is Personal.
Tools and Equipment Material Handling Travel Direct Work Personal Time Preparatory Work Waiting Steve Finally, the last category is Personal. I am now going to turn it over to Shannon Hopkins from Tennessee Eastman.

55 Work Sampling The rating should be taken at the first instant of observation. Don’t anticipate a person’s action Counts 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 observations Basic characteristics of the work situation must remain the same. Construction Methodology

56 Construction Methodology

57 Construction Methodology

58 Construction Methodology

59 Work Sampling 100% Direct Work Want to maximize
Support Delay Want to maximize Total Construction Time 0% 25% 50% 100% Break down into subcategories for class project. Construction Methodology

60 Case Study Idaho Falls Nuclear Decommissioning Project.
Treating nuclear, sodium-bearing waste from a liquid to a solid state using a steam reforming process Primary Trades: Piping, Concrete, and Instrumentation Initial Budget: $84M Final Budget: $176M Construction Methodology

61 Construction Methodology

62 Construction Methodology

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64 Construction Methodology

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67 Construction Methodology

68 Project Activity Category Wood River Project A Project B Project C
Project Activity Category Wood River Project A Project B Project C Project D Project E Average Idaho Falls Direct Work 31% 28% 42% 30% 27% 20%  Prep Work 13% 16% 8% 11% 12%  18% Tools/Equip 7% 19%  9% Mat'l Hand 4% 2% 5% 9%  3% Waiting 15% 20% 14%  19% Travel 24% 23% 17% 18%  22% Personal 6% Construction Methodology

69 Work Sampling Example: Edmonton Project
Construction Methodology

70 Work Sampling Limitations
Work Sampling provides a measure of worker efficiency Worker efficiency can only be considered an indirect measure of productivity. Reviewed with great suspicion by craftsmen and foremen Construction Methodology

71 Construction Methodology

72 Construction Methodology

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74 Construction Methodology

75 Percent 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

76 Source: 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


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