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(07) 5806 project control

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  • 1. CE 5806 Project & Site Control David Chua Kim Huat Associate Professor E2-04-08, tel: 65162195 email: cvedavidAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 2. Course Outline & Perspective  Development and Organisation of Projects (week 1) – Project phases; organisational concepts; contractual relationships  Project Planning (week 1-3) – Managerial philosophy and function of planning; network methods; resource levelling; linear scheduling;  Project Control (week 4) – Managerial philosophy and function of control; WBS; schedule and cost philosoph f nction control WBS sched le control; earned value  Advanced Methods (week 5-7) – Schedule compression; p p ; probabilistic methods; theory of constraints; lean ; y ; construction; critical chain; interface management  Productivity Improvement (week 8-9) – Factors affecting productivity; concept of work flows, capacity and bottlenecks  Site Control and Contract Management (week 10-12) – Documentation and quality management; contract management – variation and extension of time; construction safety and healthAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 3. Control of Project Cost and ScheduleKey Issues:1. Understand the key concepts in project control2. Learn the earned value approach to project control & its importance3. Know how to measure & track progress4. Use h4 U the WBS method to plan and organise project h d l d i jAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 4. Managerial Function of Control Critical to effective management is the supplying of information – Type of information – Amount of information Timeliness of control system – Reporting period & delay in the reporting information; gives dela gi es rise to time lag in control – Delay in reporting should be minimized to one or two weeks – Fast paced projects with many parties and contractual obligations must be more tightly monitored. – Amount of work progress may overwhelm scheduler. p g y – Too often costly (time, overheads). May become a nuisance. – Waiting too long to update may eliminate effectiveness of updating as a control tool – no time for corrective action – If delay, can supplement with rough and ready control systems Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 5. Managerial Function of Control Example of timeliness vs accuracy – Cost of materials can be reported at several stages and they affect the reliability of cost reports: When order is placed (commitment) Material delivered Material issued from stores Material actually used Invoice paid p If wait till invoice – long delay and useless for control purposes Commitment stage – inaccurate because may not be used or delivered but timely These are then corrected at later stagesAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 6. Managerial Function of Control Level of detail – Cost information for control if collected using cost codes existing in the company s accounting system; can be a problem company’s – Some activity based costing needed Project No Area Operation Distribution Cost 08BE02 03 096600 01 $4 000 $4,000 – Need to be balanced with the time to prepare; having approximately accurate information timely is more helpful pp y y p than accurate information 2 to 3 months after the event – Over controlled makes it cumbersome and expensive So h is S what i a good rule of thumb? d l f h b? – 20 – 80% rule Critical items in greater detail, otherwise in summary level Critical items: high proportion or high escalation Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 7. Managerial Function of Control Data vs information – 100 page report on procurement or 10 lines printout that 5 orders are likely to be late – Exception reporting, trouble spots and deviations Obj i vs subjective data and information Objective bj i d di f i – Should be as objective as possible – If subjective estimates could lead to 90% syndrome: Project appears to progress well until it is 90% complete j ll il i i l Actual progress then has to catch up Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 8. Example of CSI (Construction Specifications Institute) Format09600 Flooring09610 Floor Treatment Slip - Resistant Floor Treatment Static - Resistant Floor Treatment09620 Specialty Flooring Asphalt Plank Flooring Plastic Laminate Flooring Athletic Flooring Athl ti Fl i09630 Masonry Flooring Brick Flooring Marble Flooring Chemical - Resistant Brick Flooring Flagstone Flooring g g State Flooring g Granite Flooring Stone Flooring09640 Wood Flooring Cushioned Wood Flooring Assemblies Mastic Set Wood Flooring Assemblies Resilient Wood Flooring Assemblies Wood Athletic Flooring Wood Block Flooring Wood Composition Flooring Wood Parquet Flooring Wood Strip Flooring09650 Resilient Flooring09660 Static Control Flooring09670 Fluid-Applied Flooring09680 Carpet09690 Flooring Restoration Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 9. Approach to Control Variance Analysis Method What is the problem with this method? – Measures the difference between two factors, e.g.  Historic backward looking between actual and planned – Examples:  Not effectively used to p y portray y Planned vs actual start performance Planned vs actual finish Duration, Duration milestones Budgeted vs actual cost Manhours, unit cost, % complete Measured value vs actual cost M d l lAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 10. Approach to Control Key questions that must be – Is the rate of work accelerating or answered: decelerating as it should? – What happened in the past? Rate of build up of work – cost and Are we on schedule? progress If variation, where, why, who? S-charts What effect and what can be done? Is work within budget? Etc Thus, need to be forward looking, predicting, surfacing – What is going to happen in the trends and sensitive enough future? f to pick up adverse Are we going to be on schedule, performance as soon as it budget? occurs so that something can Important to be aware of trends in y be done to rectify it early stage to influence outcome What is final cost and completion date? Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 11. Approach to Control Data not effectively used to give integrated control Planned vs actual does not really tell PM whether more or less than budgeted have been expended. Why??Example:Activity budgeted cost cum. Budget actual cum. cost variance cum. variance in period p to date cost to date to date p period to dateA $60,000 $135,000 $66,000 $150,000 -$6,000 -$15,000B $45,000 $90,000 $39,000 $99,000 $6,000 $9,000 Does not show whether expenditure results in planned work completed Simply – variance in cost could be cost related or schedule related Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 12. Approach to Control $60,000 for A may represent the 500 units of excavation $66,000 is the actual cost of quantity not specified Say it is for 540 units and the estimated excavation cost is $120/unit Work completed is worth $64,800, thus +ve variance of $1,200 $64,800 is the earned valueExample:Activity budgeted cost cum. Budget actual cum. cost variance cum. variance in period to date cost to date to date period to dateA $60,000 $135,000 $66,000 $150,000 -$6,000 -$15,000B $45,000 $90,000 $39,000 $99,000 $6,000 $9,000 Three sets of data available that needs to be integrated to give effective control 1. Planned 2. 2 Actual 3. Value earned (“earned value”) Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 13. Earned Value ApproachExample:Activity budgeted cost cum. Budget actual cum. cost variance cum. variance p in period to date cost to date to date p period to dateA $60,000 $135,000 $66,000 $150,000 -$6,000 -$15,000B $45,000 $90,000 $39,000 $99,000 $6,000 $9,000 Quantities: 540 units Cost: $120/unit Earned value= $64,800Variance in cost = Earned value – Actual cost = $64,800 - $66,000 = -$1,200Meaning the concrete put in cost $1,200 more than it should Variance in schedule = Earned value – budget cost How much is planned? = $64,800 - $60,000 How much is done? = $4 800 $4,800 How much ahead? Meaning $4,400 more work was completed than planned Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 14. Key Cost Measures  ACWP: actual cost of work performed – amount reported as actually expended in completing work performed  BCWP: budgeted cost of work performed – budgeted amount of cost for work completed – “earned value of work performed”  BCWS: budgeted cost of work scheduled – budgeted amount of cost for the work scheduled to be p g performed  Variance Measures Alternatively – Cost variance = BCWP - ACWP va a ce CW CW C CPI = BCWP/ACWP CW / CW – Performance variance = BCWP - BCWS SPI = BCWP/BCWS  0 is favourable  1 is favourableAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 15. Earned Value Approach Usual to use labour hours for weighted value g for performance measurement Project A example Master Activities Estimated Scheduled Scheduled Estimated Man hours Man-hours Start Finish Cost (end of day) (end of day) ($1000) Site earth works 450 0 20 40 Structural works 1,000 10 40 90 Mechanical i i M h i l piping 1,500 1 500 20 70 350 Control systems 750 40 80 140 Reactor Towers 400 50 80 120 Systems Check y 300 80 95 60 Total 800Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 16. Accumulative BCWS Assumed equally distributed 1000s 0 10 20 30 40 50 60 70 80 90 95sumsite earth kworks 0 20 40 0 20 20 40structuralworks 10 40 90 0 30 30 30 90mechanicalpiping 20 70 350 0 70 70 70 70 70 350controlsystems 40 80 140 0 35 35 35 35 140reactor towers 50 80 120 0 40 40 40 120systems check 80 95 60 0 40 20 60 BCWS 0 20 50 100 100 105 145 145 75 40 20 800 accum. 0 20 70 170 270 375 520 665 740 780 800 BCWS 900 800 700 600 BCWS ($1000s) 500 400 300 200 100 0 0 20 40 60 80 100 Project Days
  • 17. At end of day 40 Master Activities % complete Actual Cost ($1000) Site earth works 100 45 Structural works 85 110 Mechanical piping 20 65 Control systems 5 10 Reactor towers - - Systems Check - - Determine progress of project in terms of cost and schedule. ACWP = $230 k BCWP = 100% x 40k 40 k 85% x 90k 76.5 k 20% x 350k 70 k 5% x 140k 7 k total $193.5 kAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 18. Schedule and Cost Variances $270K BCWS 900 ACWP 800 700 BCWS 600 Ahead BCWS ($1000s) BCWP 500 400 300 B 200 Behind 100 0 0 20 40 60 80 100 8 days Project Days behind $193.5K $193 5K $ 30 $230KAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 19. Actual progress compared with ES and LS curves BCWS 900 800 Projected 700 ES LS completion p 600 BCWS ($1000s) 500 400 Actual progress 300 B 200 100 0 0 20 40 60 80 100 Project DaysAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 20. Measurement of Work Completed  Units completed Applicable to tasks that are repetitive and require uniform effort Number of precast beams to install for floor = 120 Number of beams installed = 75 % complete = 75/120*100% = 62.5%  Start/Finish Applicable to activities of uncertain duration with no well-defined intermediate milestones. Start activities are given a percent complete say 20 30% f l 20-30% for long activities ti iti  Supervisor Opinion Informed judgement concerning completion status j g g p Dewatering, constructing temporary facilities, landscaping are usually judged this wayAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 21. Incremental milestone approach: Applicable to activities which have multiple units of work with several sequential tasks e.g. form, reinforce & pour concrete footings Foundation: Example: 150 footings Excavation 5% Excavation – 20 footings: 20*5% =1 Formwork50% Formwork – 10 footings: 10*55% = 5.5 55 Rebar/embeds 20% Rebar/embeds – 8 footings: 8*75% =6 Pour & finish 10% Pour & finish – 30 footings: 30*85% = 25.5 Strip & finish 10% Strip & finish – 20 footings: 20*95% = 19 Backfill 5% Backfill – 10 footings: = 10 Total: 67 footings out of 150 = 67/150*100% = 44.7%Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 22. Measurement of Work Completed  Cost ratio Applicable to tasks that are continuous and where costs bear a strong relationship to total effort required actual cost or work hours to date % complete  forecast to completion f t l ti  Weighted or Progress correlated to weight of material or some other units. equivalent i l t unitsAssoc Prof David Chua Dept of Civil Engrg, NUS
  • 23. Project A example Master Activities Weighted Value Unit Quantity at Quantity Actual (man-hours) completion completed man hours1.0 Site earth works 4501.1 Site grading 200 m3 5,000 4,000 1501.2 Compacted building 180 m3 10,000 7,500 150fill1.3 Fencing 70 m 800 610 60 Master Activities Weighted Value Man-hrs Actual man ( (man-hours)) earned hours1.0 Site earth works 4501.1 Site grading 200 4000/5000 x 200 160 1501.2 Compacted building fill 180 7500/10000 x 180 135 1501.3 Fencingg 70 610/800 x 70 53.4 60 Total 348.4 360 Percent complete = 348.4/450 = 77.4% Productivity = 348.4/360 = 96.8% Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 24. Network- Network-based Control System Requires a well-defined work  Work breakdown structure - plan, plan budget and schedule smallest unit is the work package – provides the benchmarks for – work defined in sufficient detail control to be be measured, budgeted, Must be developed with inputs scheduled and controlled from people performing the work – several WPs in one activity or single WP comprising several Must be communicated to all activities participants  Difference between network To be effective, must be simple to approach and cost accounting administer and easily understood approach by all participants  Efficiency of system – decide on level of detail, quantity of information, frequency of collection ll i Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 25. Work Breakdown Structure BuildingSite work Foundations Structure Curtain wall Finishes Electrical Survey Excavation Piles Pile caps Ground beams Test piles Area 1 Area 2 Drive piles Inspect Clean Rebar Pour concrete WBS used in planning stage to identify tasks and subtasks Assign responsibilities, achieve management control No fixed rule for level of detail and breakdown structure Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 26. WBS Hierarchy Power S StationBoiler house Turbine house Coal handling Water cooling plant plant Cooling Condenser Turbine blocks Retaining walls water pipes foundations Foundations Columns Machine platform Rebar Prepare Formwork Erect formwork Assoc Prof David Chua Dept of Civil Engrg, NUS
  • 27. WBS with organisation structure Oranizational structure ucture eakdown Stru Work BreAssoc Prof David Chua Dept of Civil Engrg, NUS