CIVL202
Construction
Engineering I
Tutorial 8
T1
Mon
T2
Wed
11:00 – 11:50
09:00 – 09:50
Tutorial Outline
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Developing WBS
Cost control
Bar chart
Scheduling network
Developing WBS
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The definition of WBS is “ the progressive
hierarchical break-down of the project into
smaller pieces to the lowest practical level to
which cost is applied”.
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The aim of WBS is extremely useful in
developing both cost and time (schedule) plans
to monitoring and controlling a project.
We can think about that Why was Construction
Project Management developed?
Developing WBS
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In establishing the WBS, the following
guidelines need to be considered:
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Be clearly separated from other work packages.
Each work package must have unique starting and
ending dates.
Each work package should have its own unique budget.
Work packages should be small enough that precise
measurement of work progress is possible.
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Maybe these points can be comprehended in Construction
Project completely.
Determining Sequence of
Work packages
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Activity is the work elements which appear in the
schedule in their expected sequence or logical order.
The criteria of arranging the work packages sequence for
time control:
Location
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After completing the structure frame of the first floor of a
building before beginning the second. This is a physical
constraints.
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Material
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The building structure isn’t erected until the foundation of a
building have reached sufficient strength. This is a physical
constraints.
Determining Sequence of
Work packages
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Method of construction technology
This is a technology constraint. Different technologies have
different sequences.
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Required resources
If the Required resources can’t be gotten, the sequence
must be changed.
Cost Control Related to
WBS
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Procedure of cost control:
Develop bid estimate.
If bid is accepted, develop contract budget based on
major work items.
Measure actual cost on project.
Compare actual costs with control budget.
Take corrective actions ( measurement of reducing
cost).
If can’t complete the project, could revise contract
budget.
Cost Control Related to
WBS
Code of account is a template or
guide in defining and cataloging the
cost centers within a project.
 Cost coding system utilize a
numerical or alpha-numerical
labeling which is a multi-level or
hierarchical in nature, just to be
consistent with WBS.
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Cost Control Related to
WBS
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A typical cost type might define:
(1) the project designator
(2)area of work
(3)work discipline( e.g. civil, mechanical,
electrical, etc.)
(4) the trade specialty required.
A cost coding system need to be handled by
computer easily.
Attention
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The WBS provides a rigorous way to
quantify, define, measure, and control the
work packages of a given scope of work.
Other plans can be developed based on the
WBS.
Procurement plan
Safety plan
Quality plan
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Bar Chart
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Bar chart : the representation of a project
work item/activity as a time scaled bar
whose length represents the planned
duration of the activity.
Length of the bar has two meanings:
Its physical length represents the planned duration of the
work activity.
 The bar provides a proportionally scaled baseline to plot
at successive intervals the correct percentage complete.
By using different shading patters, bar chart can indicate
monthly progress toward physical completion of work
activities.
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Bar Chart
A bar-net is a updated bar chart.
 MS-Project-XP; P3; and so on can
draw the bar-net.
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Scheduling Network
In order to develop a schedule, the
logical sequences that relates various
activity to on another must be
developed.
 Logical modeling rationales:
 Adjacency of contact modeling
 Physical structure order modeling
 Physical construction order modeling
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Scheduling Network
A scheduling network of nodes and
links
 The node may represent events in
time or an activity depending on the
Activity name
notation.
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A
10
The duration tim
A, Node to present and event
B, Node to represent an activity
Scheduling Network
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Activity on node means that a network of
activities is shown in which nodes represent
the activities and arrows represent the
sequences or relationship of the activity to
one another.
Activity on Arrow means that a network of
activities is shown in which nodes represent
events in time and arrows represent
activities.
Scheduling Network
Dummy Activity
 1,Maintain logic sequence
 2,Maintain specific activity
 3,Zero duration.
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