Critical Path Method (CPM) is basically a step-by-step Project Management technique that separates planning and scheduling...

1. Critical Path Method
&
Network Analysis
Soc 3210 : Project Designing and Management

2. Presentation Summary..
Critical Path Method
• Project Management
• Critical Path
• Critical Path Method (CPM)
• Origin of CPM
• Why CPM is Important
• Terms Related to CPM
• Procedure of CPM
• Example
• Advantages/Disadvantages
• Network Analysis
• Network
• Network Analysis
• Terms related to Network Analysis
• Activity-on-Arc (AOA) Network
• Concurrent Activities
• Dummy Activities
• Example
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3. What is Project Management??
 Project management is the
discipline of initiating, planning,
executing, controlling, and closing
the work of a team to achieve
specific goals and meet specific
success criteria.
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4. What is Critical Path??
• The sequence of project activities
which add up to the longest overall
duration.
• The critical path determines the
shortest time possible to complete
the project.
4

5. What is Critical Path Method??
• Critical Path Method (CPM) is basically a step-by-step Project
Management technique that separates planning and scheduling.
• It also clarifies the inter relationship of time and cost.
• CPM evaluates all the possible
alternative plans for project and
associates each plans with a
schedule.
• It is a mathematical based
algorithm for scheduling a set of
project activities.
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6. The origins of CPM
• The CPM was developed in the 1950s by Morgan R. Walker of
DuPont (Chemical Company) and James E. Kelley Jr. of Remington
Rand (Machines Manufacturer).
• It was first used in a missile-defense construction project.
• Since that time, the CPM has been adapted to other fields including
hardware and software product research and development.
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7. Where is it used??
And many more…
PROJECTS
Software Development
Construction
Aerospace & Defense
Research Projects
Product Development
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8. Why CPM is important??
• According to Dr. Larry Bennett (1978), the critical path method also
has three main benefits for project managers. They are…
Identifies the Most
Important Tasks
Helps to Reduce
Timelines
Compares Planned with
Actual
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9. Key Steps in the Critical Path Method...
• There are six key steps in the critical path method. They are..
Specify Each ActivityStep 1
Draw the Network DiagramStep 3
Establish Dependencies
(Activity Sequence)
Step 2
Update the Critical Path
Diagram to Show Progress Step 6
Identify the Critical Path Step 5
Estimate Activity Completion
Time
Step 4
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10. Key Steps in the Critical Path Method...
• Step 1 : Specify Each Activity
• The first step is to identify the main deliverables of a project. Then
you can start breaking down the high-level activities into smaller
chunks of work.
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11. Key Steps in the Critical Path Method...
• Step 2 : Establish Dependencies (Activity Sequence)
• Some activities will depend on the completion of others. Listing the
immediate predecessors of each activity will help you identify the
correct order.
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12. Key Steps in the Critical Path Method...
• Step 3 : Draw the Network Diagram
• Once you have identified the activities and their dependencies, you
can draw the critical path analysis chart (CPA), known as the
network diagram.
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13. Key Steps in the Critical Path Method...
• Step 4 : Estimate Activity Completion Time
• Using past experience or the knowledge of an experienced team
member, you must now estimate the time required to complete
each activity. If you are managing a smaller project, you will most
likely estimate time in days. If you are working with a complex
project, you may have to measure time in weeks.
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14. Key Steps in the Critical Path Method...
• Step 5 : Identify the Critical Path
• There are two ways you can now identify the critical path.
1. You can eyeball your network diagram and simply identify the longest path
throughout the network (in terms of longest duration in days).
2. You can also identify critical activities with the Forward Pass/Backward
Pass technique, identifying the earliest start and finish times, and the latest
start and finish times for each activity.
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15. Key Steps in the Critical Path Method...
• Step 6 : Update the Critical Path Diagram to Show Progress
• As the project progresses, you will learn the actual activity
completion times. The network diagram can then be updated to
include this information (rather than continuing to use
estimations).
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16. Terms Related to CPM
• Float(slack): It is the amount of time an activity can be delayed
without delaying the project.
• Crashing: Reducing a project’s duration is called crashing.
• Critical activity: Activity with zero float.
• Resource leveling: It is an iterative process of assigning crews to
activities in order to calculate their duration.
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17. Calculation of CPM
• Earliest Start Time (EST)
• Earliest Finish Time (EFT)
• Latest start time (LST)
• Latest Finish Time (LFT)
• The longest path of planned
activities to the end of the
project.
• The earliest and latest that each
activity can start and finish
without making the project
longer.
• We have to determine “critical”
activities.
• Crashing the critical path.
Need to find the following for each activity:
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18. Class Exercise..
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19. Example..
• Orange Square:
Calculated Value
• White Circle:
Duration
• Black hexagon:
Crashing Value
• Critical Path:
A-C-G-H
A C
STAR
T
G
B D E
H
7
3
6 3
F
3 3
2 3
2
2
7 13 16
3 6
5
9
1816137
0
1613
13
10
0
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20. Advantages of CPM
• Consistent framework for planning, scheduling, monitoring, and
controlling project.
• Helps proper communications between departments and
functions.
• Determines expected project completion date.
•Determines the dates on which tasks may be started or must be
started if the project is to stay in schedule.
•Shows which tasks must be coordinated to avoid resource or
timing conflicts.
•Shows which tasks may run in parallel to meet project
completion date.
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21. Disadvantages of CPM
• Reliability of CPM largely based on accurate estimates and
assumptions made.
• CPM does not guarantee the success of project.
• Resources may not actually be as flexible as management hope
when they come to address network float.
• Too many activities may the network diagram too complicated.
• Activities might themselves have to be broken down into mini
projects.
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22. Network Analysis

23. What is Network??
Any system of interconnected linear features..
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24. What is Network Analysis??
• Network Analysis is a technique for planning and controlling large
projects, such as construction work, Research & Development
projects, computerization of systems etc.
• Its primary aim is to program and monitor the progress of a project
so that the project is completed in the minimum time. In doing this,
it pinpoints the parts of the project which are “crucial”.
• It can also be used in allocating resources such as labor and
equipment and thus helps to make the total cost of a project
minimum.
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25. Network Analysis Methods
• Network Analysis methods is a group of special analytical
methods that are used in cases where it is necessary to analyze and
optimize a network of interconnected and related elements that
have some connection between one another.
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26. Basic Network Analysis Methods
• CPM (Critical Path Method)
• CCM (Critical Chain Method)
• PERT Method (Program Evaluation and Review Technique)
• GERT Method (Graphical Evaluation and Review Technique)
• MPM Method (Metra Potential Method)
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27. Terms related to Network Analysis
• WBS: Break down the project into constituent activities such that each
activity is clearly identifiable and manageable
• Activity: This is a physically identifiable part of the project that consumes
time and resources. It is represented by an arrow (in AOA diagrams)
• Events (node): These are the beginning or end points of an activity. Event
is a point in time and does not consume any time or resource and is
represented by a circle.
• Path: This is a continuous chain of activities from the beginning to the
end of the project.
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28. Terms related to Network Analysis
Activity-on-Arc (AOA) Network
• A branch reflects an activity of a project.
• A node represents the beginning and end of activities, referred to
as events.
• Branches in the network indicate precedence relationships.
• When an activity is completed at a node, it has been realized.
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29. Terms related to Network Analysis
Concurrent Activities
• Activities can occur at the same time (concurrently).
• Network aids in planning and scheduling.
• Time duration of activities shown on branches.
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30. Terms related to Network Analysis
Dummy Activities
• A dummy activity shows a precedence relationship but reflects no
passage of time.
• Two or more activities cannot share the same start and end nodes.
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31. Example..
• Draw the AON network for this project.
• What is the Critical Path and Project Duration?
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32. Solution..
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33. Thanks for patient hearing.
Any Questions??