Part_2 as Planned S Curves

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Project Control: Developingthe As-Planned S-Curves

Part #2November 28, 2010

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Purpose

Illustrate how to develop a set of As-Planned S-Curves from schedulinginformation and estimates developedsometime before actual constructionoperations begin.

Review the conceptual design estimatingprocess to the extent necessary to set thecontext.



Learning Objectives

Be able to construct an as-planned scheduleof work and cost versus elapsed time from a

typical (but simplified) construction project Gantt Chart.

Be able to plot and identify the as Planned S-Curves best representing these schedules.



W ho Develops the As PlannedGantt Chart? And W hen?

It depends upon what part of the process isin question.

W e are going to assume that the Gantt Chart is developed by the Contractor to planconstruction operations.W e are going to assume that the scheduledata are generated sometime before theonset of actual field operations.



Example Construction Project

The project is to reconstruct 2-miles of parkaccess road conforming to Texas FM-Road

standards. This involves the following tasks:1. 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. W earing Course construction shoot and chip5. Demobilization Clean up, equipment, office,

etc.



Class Discussion Exercise #2.1on Construction Methods.

Ask Selected Individuals or Pairs to answer thefollowing:

W hat is Base Material and what is its purposein the design of the road?How is the Base built?W hat is shoot and chip?W hat is Pea Gravel?W hat is the design profile of a FM Road?



Project Task Duration andCost Data

Assume: All labor, material and equipment cost estimates areavailable from the estimating process.Maximum Task overlap with a 1-day minimum delay onan early start schedule.

Days $$/Day1 Mobilization 1 1,0002 Sub Base 10 3,5003 Base 11 51,0004 Pave 4 25,0005 Demobilization 2 1,000

Task



Assumed Estimating Process

The entire project is broken into W ork Packages (workbreakdown 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 areobtained from historical data W e will use the R. S. Meansmanual in this class.

W ork Package (or Task or Activity) durations and costs arederived from the historical data as applied to the estimates.These data serve as inputs to the scheduling process whichresult in Bar-Charts similar to the one on the next slide.



Class Exercise 2.2

As individuals describe the crew(equipment and personnel) configurationnecessary to construct the base course.

As Pairs agree upon the configuration. As a Team, estimate the hourly cost rate.



Example Gantt Chart withRelated S-Curve % Data

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.

Task Days $$/Day ES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17M 1 1,000$ 1 MS 10 4,000$ 2 S S S S S S S S S SB 11 50,000$ 3 B B B B B B B B B B BS 4 25,000$ 12 S S S SD 2 1,000$ 16 D D

1 , 0 0 0

4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

5 4 , 0 0 0

7 5 , 0 0 0

7 5 , 0 0 0

2 5 , 0 0 0

2 5 , 0 0 0

1 , 0 0 0

1 , 0 0 0

6 9 3 , 0 0 0

0 % 1 % 9 % 1 6 %

2 4 % 3 2 %

4 0 % 4 7 %

5 5 % 6 3 %

7 1 % 8 2 %

9 2 % 9 6 %

1 0 0 %

1 0 0 %

1 0 0 %

1 0 0 %

1 1 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 2 8

4 % 7 % 1 4 %

2 1 % 2 9 %

3 6 % 4 3 %

5 0 % 5 7 %

6 4 % 7 1 %

7 9 % 8 6 %

8 9 % 9 3 %

9 6 % 1 0 0 %

1 0 0 %

D a i l y

C o s t

D a i l y

W o r k

C u m u

l a t i v e

C o s t

i n $ $ ' s

C u m m u l a t i v

e W o r k U n i t s



Class Exercise #2.3

As Individuals, compute the number of cubic yards of base material required tobuild 2-miles of FM Road base, 24-feet wide, and 1-foot thick?

As Pairs, compare answers and then

compute the linear feet of dailyprogress, if you can build 2,700 sq-ydsof base per day?



W hat Does allthis Imply?The relationship betweentime and cost and timeand work.

For example, at the end of day 8 you plan to have

completed 50% of theW ork and to have spent 47% of the Budget.

Day Cost % Work %1 0% 4%

2 1% 7%3 9% 14%4 16% 21%5 24% 29%6 32% 36%7 40% 43%8 47% 50%9 55% 57%

10 63% 64%11 71% 71%12 82% 79%

13 92% 86%14 96% 89%15 100% 93%16 100% 96%17 100% 100%



Corresponding As-Planned S-Curves

As P a ed - es

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18ched e a s

a t i v e

s t

0%

20%

40%

60%

80%

100%

120%

140%

160%

180%

200%

u m u l a t i v e

k

Note: Therelationship

between thescales. Thereis a reason to make

room for the As-Built S-Curves



Exercise #2.4

Individually, usingengineering paper,

plot the S-Curves forthese data, label theaxes, the curves, andthe plot.

Turn in your workbefore you leave.

Day Cost % W o r %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %

% %



Module Assessment Question

If you had to ask a question about thistopic, what would it be?

Part_2 as Planned S Curves

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