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Project Control: Developing
the As-Planned S-Curves
Part #2
July 5, 2017
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Purpose
Illustrate how to develop a set of AsPlanned S-Curves from scheduling
information and estimates developed
sometime before actual construction
operations begin.
Review the conceptual design estimating
process to the extent necessary to set the
context.
Learning Objectives
Be able to construct an as-planned schedule
of work and cost versus elapsed time from a
typical (but simplified) construction project
Gantt Chart.
Be able to plot and identify the as Planned SCurves best representing these schedules.
Who Develops the As Planned
Gantt Chart? And When?
It depends upon what part of the process is
in question.
We are going to assume that the Gantt Chart
is developed by the Contractor to plan
construction operations.
We are going to assume that the schedule
data are generated sometime before the
onset of actual field operations.
Example Construction Project
The project is to reconstruct 2-miles of park
access road conforming to Texas FM-Road
standards. This involves the following tasks:
Mobilization – Equipment, office set up, etc.
2. Sub-base preparation – hauling, grading and
compaction, redo of some culverts, etc.
3. Base course construction – hauling, grading and
compaction.
4. Wearing Course construction – shoot and chip
5. Demobilization – Clean up, equipment, office,
etc.
1.
Class Discussion Exercise #2.1
on Construction Methods.
Ask Selected Individuals or Pairs to answer the
following:
What is Base Material and what is its purpose
in the design of the road?
How is the Base built?
What is “shoot and chip?”
What is Pea Gravel?
What is the design profile of a FM Road?
Project Task Duration and Cost
Data
Task
1 Mobilization
2 Sub Base
3 Base
4 Pave
5 Demobilization
Days
1
10
11
4
2
$$/Day
1,000
3,500
51,000
25,000
1,000
Assume:
All labor, material and equipment cost estimates are
available from the estimating process.
Maximum Task overlap with a 1-day minimum delay on
an early start schedule.
Assumed Estimating Process
The entire project is broken into Work Packages (work
breakdown structure): build base, shoot and chip, etc.
Estimated unit quantities for each work package are calculated
from the plans and specifications at an appropriate level of
detail.
The corresponding unit prices and productivity rates are
obtained from historical data – We will use the R. S. Means
manual in this class.
Work Package (or Task or Activity) durations and costs are
derived from the historical data as applied to the estimates.
These data serve as inputs to the scheduling process which
result in Bar-Charts similar to the one on the next slide.
Class Exercise 2.2
As individuals describe the crew
(equipment and personnel) configuration
necessary to construct the base course.
As Pairs agree upon the configuration.
As a Team, estimate the hourly cost rate.
Example Gantt Chart with
Related S-Curve % Data
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17
S
S
B
S
B
S
B
S
B
S
B
S
B
S
B
S
B
B
S
B
S
S
S
100%
100%
100%
100%
1
1
1
28
93%
96%
100%
100%
1,000
96%
1
89%
25,000
92%
2
86%
25,000
82%
2
79%
75,000
71%
2
71%
75,000
63%
2
64%
54,000
55%
2
57%
54,000
47%
2
50%
54,000
40%
2
43%
54,000
32%
2
36%
54,000
24%
2
29%
54,000
16%
2
21%
54,000
9%
2
14%
54,000
1%
1
7%
54,000
0%
4,000
D
1
1,000
D
693,000
S
B
1,000
1
M
4%
Cumulative
Cost in $$'s
ES
1
2
3
12
16
Cummulativ
e Work Units
$$/Day
$ 1,000
$ 4,000
$ 50,000
$ 25,000
$ 1,000
Daily Cost
Days
1
10
11
4
2
Daily Work
Task
M
S
B
S
D
Simplifying assumptions: All work is equally weighted where 1 day equals 1 unit of
work. Daily work accomplished is NOT a function of daily cost.
Class Exercise #2.3
As Individuals, compute the number of
cubic yards of base material required to
build 2-miles of FM Road base, 24-feet
wide, and 1-foot thick?
As Pairs, compare answers and then
compute the linear feet of daily
progress, if you can build 2,700 sq-yds
of base per day?
What Does all
this Imply?
The relationship between
time and cost and time
and work.
For example, at the end of
day 8 you plan to have
completed 50% of the
Work and to have spent
47% of the Budget.
Day
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Cost % Work %
0%
4%
1%
7%
9%
14%
16%
21%
24%
29%
32%
36%
40%
43%
47%
50%
55%
57%
63%
64%
71%
71%
82%
79%
92%
86%
96%
89%
100%
93%
100%
96%
100%
100%
Corresponding As-Planned SCurves
100%
200%
90%
180%
80%
160%
70%
140%
60%
120%
50%
100%
40%
80%
30%
60%
20%
40%
10%
20%
0%
0%
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Schedule in Days
Cumulative Work
Note: The
relationship
between the
scales. There
is a reason –
to make
room for the
As-Built
S-Curves
Cummulative Cost
As Planned S-Curves
Exercise #2.4
Individually, using
engineering paper,
plot the S-Curves for
these data, label the
axes, the curves, and
the plot.
Turn in your work
before you leave.
Day
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Cost % Work %
0%
4%
1%
7%
9%
14%
16%
21%
24%
29%
32%
36%
40%
43%
47%
50%
55%
57%
63%
64%
71%
71%
82%
79%
92%
86%
96%
89%
100%
93%
100%
96%
100%
100%
Module Assessment Question
If you had to ask a question about this
topic, what would it be?