3. Contents
INTRODUCTION
DEFINITIONS OF PROJECT AND PROJECT MANAGEMENT
NETWORK PLANNING METHODS
WHAT IS NETWORK
CONSTRUCTION OF NETWORK
CPM
PERT
CPM VS PERT
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4. INTRODUCTION
To perform any job optimally we should have some planning
Generally planning and performing job is called project.
The project requires some techniques to done the project
Those are CPM and PERT
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5. Definitions
Project:
project is a group or combination of activities that must be executed in a certain
fixed order before entire task is completed.
The projects are non-repetitive large tasks
Project management:
Project management is a scientific way of planning, implementing, monitoring &
controlling the various aspects of a project such as time, money, materials,
manpower & other resources.
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6. Real time example for a project
Project: Getting ready to attend the college
Wake up in the Morning
Brush your teeth
Take bath
Wear formal dress
Take break fast
Walk to the college
These are the basic activities we need to complete for accomplishment of project.
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7. Network Planning methods
Methods used for network planning are:
CPM
PERT
Managing a project with network planning methods involves four steps:
Describing the project.
Diagramming the Network.
Estimating time of completion.
Monitoring project progress.
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8. Network Diagram
Network:
Network is a graphical representation of a project operations and it is
composed of several activities and events which are inter-related.
Network consists of:
Event
Activity
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9. Basic Building blocks of Network
Activity:
Activity is a recognizable part of the project which consume time and resources for its
completion.
In network diagram “ARROW” represents activity
Critical activity
Dummy activity
Event:
An event represents the accomplishment of some task. In a network diagram,
beginning and ending of an activity represented by an event.
In network diagram “NODE” represents event.
Merge event
Burst event
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10. Construction of a Network
Rules for drawing network diagram
1. Each activity is represented by one and only one arrow in the network
2. No two activities can be identified by the same end events
3. Before an activity can begin, it preceding activities must be completed.
4. Arrows indicate logical precedence.
5. Flow of the diagram is from left to right
6. Arrows should not intersect.
7. Dangling should be avoided.
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12. CPM
CPM means “critical path method”.
It is a network technique used to evaluate the project.
If the activity times are deterministic then critical path method can be used as a
systematic method.
CPM evaluates project by determining critical path in the network.
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13. Critical Path
Critical path is the longest path in the network from the starting event to ending
event
Critical path defines minimum time required to complete the project
In network diagram critical path is represented with double arrows
Critical path consist:
Critical event: The events with zero slack
Critical activity: The activities with zero total float
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14. Network of CPM
Earliest Activity start time(EST)
The earliest start time that an activity can be started
Earliest Activity finish time(EFT)
EFT= EST + Duration
Latest Activity finish time(LFT)
Latest Activity start time(LST)
LST= LFT-duration
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15. Types of Float
Total float
(TF)ij = (Lj – Tij)- Ei
Free float
(Ff)Ij =Total float – ( Lj- Ej)
Independent float
(If)ij = Free float- Tail event slack
Tiji j
Ei Ej
Li Lj
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16. Draw network diagram and analyzing CPM
Activity Immediate
predecessor
Duration
(months)
A -------------- 2
B -------------- 5
C -------------- 4
D B 5
E A 7
F A 3
G B 3
H C,D 6
I C,D 2
J E 5
K F,G,H 4
L F,G,H 3
M I 12
N J,K 8
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17. PERT
PERT means project (or) programme Evaluation & Review Technique.
When activity times are probabilistic, PERT is an effective tool for evaluate
project.
PERT is associated with 3 time estimates
Optimistic Time ( to)
Pessimistic Time ( tP)
Most likely Time ( tm)
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18. Activity Times in PERT
Optimistic Time: ( To)
It is the minimum time that is required to complete an activity when every
resource is available
Most likely Time: (Tm)
This is the time required for the completion of activity under normal conditions.
Pessimistic Time: (Tp)
The most time that is required to complete activity when every resource is not
available
Note: In PERT β – distribution is used to represent these three time estimates
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19. Formulae used for evaluation of PERT
Time estimate (Te)=
𝑇𝑜+𝑇𝑝+4𝑇𝑚
6
Standard deviation ( )= 𝑇𝑝 −𝑇𝑂
6
Variance =
𝑇𝑝−𝑇𝑜 2
36
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20. CPM VS PERT
CPM PERT
It is activity oriented It is event oriented
It is associated with deterministic activities It is associated with probabilistic activities
It is based upon single time to complete
an activity
It is based upon 3 time estimate to
complete an activity
It is used mainly for construction project It is used mainly for research and
development project
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