1. CE 5806 Project & Site Control
David Chua Kim Huat
Associate Professor
E2-04-08, tel: 65162195 email: cvedavid
Assoc 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 health
Assoc Prof David Chua Dept of Civil Engrg, NUS
3. Control of Project Cost and Schedule
Key Issues:
1. Understand the key concepts in project control
2. Learn the earned value approach to project control & its
importance
3. Know how to measure & track progress
4. Use h
4 U the WBS method to plan and organise project
h d l d i j
Assoc 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 stages
Assoc 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) Format
09600 Flooring
09610 Floor Treatment Slip - Resistant Floor Treatment
Static - Resistant Floor Treatment
09620 Specialty Flooring Asphalt Plank Flooring Plastic Laminate Flooring
Athletic Flooring
Athl ti Fl i
09630 Masonry Flooring Brick Flooring Marble Flooring
Chemical - Resistant Brick Flooring
Flagstone Flooring
g g State Flooring
g
Granite Flooring Stone Flooring
09640 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 Flooring
09650 Resilient Flooring
09660 Static Control Flooring
09670 Fluid-Applied Flooring
09680 Carpet
09690 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 l
Assoc 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 date
A $60,000 $135,000 $66,000 $150,000 -$6,000 -$15,000
B $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 value
Example:
Activity budgeted cost cum. Budget actual cum. cost variance cum. variance
in period to date cost to date to date period to date
A $60,000 $135,000 $66,000 $150,000 -$6,000 -$15,000
B $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 Approach
Example:
Activity budgeted cost cum. Budget actual cum. cost variance cum. variance
p
in period to date cost to date to date p
period to date
A $60,000 $135,000 $66,000 $150,000 -$6,000 -$15,000
B $45,000 $90,000 $39,000 $99,000 $6,000 $9,000
Quantities: 540 units
Cost: $120/unit
Earned value= $64,800
Variance in cost = Earned value – Actual cost
= $64,800 - $66,000
= -$1,200
Meaning 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 favourable
Assoc 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 800
Assoc Prof David Chua Dept of Civil Engrg, NUS
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 k
Assoc Prof David Chua Dept of Civil Engrg, NUS
18. Schedule and Cost Variances
$270K
BCWS
900
ACWP
800
700 BCWS
600
Ahead
BCWS ($1000's)
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
$230K
Assoc 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 ($1000's)
500
400
Actual progress
300
B
200
100
0
0 20 40 60 80 100
Project Days
Assoc 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 way
Assoc 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
units
Assoc 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 hours
1.0 Site earth works 450
1.1 Site grading 200 m3 5,000 4,000 150
1.2 Compacted building 180 m3 10,000 7,500 150
fill
1.3 Fencing 70 m 800 610 60
Master Activities Weighted Value Man-hrs Actual man
(
(man-hours)) earned hours
1.0 Site earth works 450
1.1 Site grading 200 4000/5000 x 200 160 150
1.2 Compacted building fill 180 7500/10000 x 180 135 150
1.3 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
Building
Site 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
Station
Boiler 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 Bre
Assoc Prof David Chua Dept of Civil Engrg, NUS
