Project Control: Developing the As-Planned S-Curves

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					Project Control: Developing
the As-Planned S-Curves
Part #2
March 3, 2012
Hide/Unhide Exercises
Purpose
 Illustrate how to develop a set of As-
 Planned 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 S-
  Curves 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:
  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. Wearing Course construction – shoot and chip
  5. Demobilization – Clean up, equipment, office,
     etc.
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                     Days      $$/Day
   1 Mobilization           1         1,000
   2 Sub Base               10        3,500
   3 Base                   11       51,000
   4 Pave                   4        25,000
   5 Demobilization         2         1,000
Assume:
  All labor, material and equipment cost estimates are
  available from the estimating process.
  Maximum Task overlap with a 1-day minimum delay on
  an early start schedule.
Assumed Estimating Process
 The entire project is broken into Work Packages (work
 breakdown structure): build base, shoot and chip, etc.
 Estimated unit quantities for each work package are calculated
 from the plans and specifications at an appropriate level of
 detail.
 The corresponding unit prices and productivity rates are
 obtained from historical data – We will use the R. S. Means
 manual in this class.
 Work Package (or Task or Activity) durations and costs are
 derived from the historical data as applied to the estimates.
 These data serve as inputs to the scheduling process which
 result in Bar-Charts similar to the one on the next slide.
Class Exercise 2.2
 As individuals describe the crew
 (equipment and personnel) configuration
 necessary to construct the base course.
 As Pairs agree upon the configuration.
 As a Team, estimate the hourly cost rate.
   Example Gantt Chart with
   Related S-Curve % Data
     Task          Days    $$/Day      ES           1        2       3        4        5        6        7        8        9       10 11 12 13 14 15 16 17
      M              1    $ 1,000       1           M
      S             10    $ 4,000       2                   S       S        S        S        S        S        S        S        S        S
      B             11    $ 50,000      3                           B        B        B        B        B        B        B        B        B        B        B
      S              4    $ 25,000     12                                                                                                            S        S        S        S
      D              2    $ 1,000      16                                                                                                                                                D       D




                                                                                                                                                                                                         693,000
                                                                    54,000
                                                                             54,000
                                                                                      54,000
                                                                                               54,000
                                                                                                        54,000
                                                                                                                 54,000
                                                                                                                          54,000
                                                                                                                                   54,000
                                                                                                                                            54,000
                                                                                                                                                     75,000
                                                                                                                                                              75,000
                                                                                                                                                                       25,000
                                                                                                                                                                                25,000
                                     Cost in $$'s
                                                    1,000
                                                            4,000




                                                                                                                                                                                         1,000
                                                                                                                                                                                                 1,000
                                     Cumulative
      Daily Cost




                                                                                                                                                                                100%

                                                                                                                                                                                         100%

                                                                                                                                                                                                 100%
                                                                                                                                                                                                         100%
                                                                             16%

                                                                                      24%

                                                                                               32%

                                                                                                        40%

                                                                                                                 47%

                                                                                                                          55%

                                                                                                                                   63%

                                                                                                                                            71%

                                                                                                                                                     82%

                                                                                                                                                              92%

                                                                                                                                                                       96%
                                                    0%

                                                            1%

                                                                    9%
                                     e Work Units
                                     Cummulativ
      Daily Work




                                                                                                                                                                                                         28
                                                    1
                                                            1
                                                                    2
                                                                             2
                                                                                      2
                                                                                               2
                                                                                                        2
                                                                                                                 2
                                                                                                                          2
                                                                                                                                   2
                                                                                                                                            2
                                                                                                                                                     2
                                                                                                                                                              2
                                                                                                                                                                       1
                                                                                                                                                                                1
                                                                                                                                                                                         1
                                                                                                                                                                                                 1
                                                                                                                                                                                                 100%
                                                                                                                                                                                                         100%
                                                                    14%

                                                                             21%

                                                                                      29%

                                                                                               36%

                                                                                                        43%

                                                                                                                 50%

                                                                                                                          57%

                                                                                                                                   64%

                                                                                                                                            71%

                                                                                                                                                     79%

                                                                                                                                                              86%

                                                                                                                                                                       89%

                                                                                                                                                                                93%

                                                                                                                                                                                         96%
                                                    4%

                                                            7%




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                Day   Cost % Work %

this Imply?                   1
                              2
                                     0%
                                     1%
                                            4%
                                            7%
                              3      9%    14%
The relationship between      4     16%    21%
time and cost and time        5
                              6
                                    24%
                                    32%
                                           29%
                                           36%
and work.                     7     40%    43%
                              8     47%    50%
                              9     55%    57%
For example, at the end of   10     63%    64%
day 8 you plan to have       11
                             12
                                    71%
                                    82%
                                           71%
                                           79%
completed 50% of the         13     92%    86%
Work and to have spent       14     96%    89%
                             15     100%   93%
47% of the Budget.           16     100%   96%
                             17     100%   100%
  Corresponding As-Planned S-
  Curves
                                                     As Planned S-Curves
                                   100%                                                    200%
Note: The                          90%                                                     180%
relationship                       80%                                                     160%

between the
                Cummulative Cost
                                   70%                                                     140%




                                                                                                  Cumulative Work
scales. There                      60%                                                     120%

is a reason –                      50%                                                     100%

to make                            40%                                                     80%


room for the
                                   30%                                                     60%

                                   20%                                                     40%
As-Built                           10%                                                     20%
 S-Curves                           0%                                                     0%
                                          0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
                                                        Schedule in Days
Exercise #2.4             Day
                           1
                                Cost % Work %
                                  0%     4%
                           2      1%     7%
                           3      9%    14%
                           4     16%    21%
  Individually, using      5     24%    29%
  engineering paper,       6     32%    36%
  plot the S-Curves for    7     40%    43%
                           8     47%    50%
  these data, label the    9     55%    57%
  axes, the curves, and   10     63%    64%
  the plot.               11     71%    71%
                          12     82%    79%
  Turn in your work       13     92%    86%
  before you leave.       14     96%    89%
                          15     100%   93%
                          16     100%   96%
                          17     100%   100%
Module Assessment Question
  If you had to ask a question about this
  topic, what would it be?

				
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