Unit 2
Time Management
Prepared by: Prof. Seemaah Keddar
Time Management
Activity Definition
Tools and Techniques for Activity
Definition
Outputs from Activity Definition
Activity Sequencing
Activity Sequencing
Inputs to Activity sequencing
Inputs to Activity sequencing
Tools and Techniques for Activity sequencing
Tools and Techniques for Activity sequencing
Tools and Techniques for Activity sequencing
Tools and Techniques for Activity sequencing
Output from Activity sequencing
Activity Duration Estimation
Inputs to Activity Duration Estimation
Tools and Techniques for Activity Duration
Estimation
Tools and Techniques for Activity Duration
Estimation
Tools and Techniques for Activity Duration
Estimation
Schedule Development
Inputs to Schedule Development
Inputs to Schedule Development
Inputs to Schedule Development
Tools & Techniques for Schedule Development
Critical path method (CPM)
• It is Network analysis technique used in complex project plans
with a large number of activities. CPM diagrams (1) all
activities, (2) time required for their completion, (3) and how
each activity is related to the previous and next activity. A
sequence of activities is called a 'path,' and the longest-path
in the diagram is the critical path. It is 'critical' because all
activities on it must be completed in the designated time,
otherwise the whole project will be delayed.
CPM
Example:
Activity Description Required Predecessor Duration A Product
design (None) 5 months B Market research (None) 1 C
Production analysis A 2 D Product model A 3 E Sales brochure A
2 F Cost analysis C 3 G Product testing D 4 H Sales training B, E 2
I Pricing H 1 J Project report F, G, I 1 .
Example 1 Step 2: Draw the diagram
• Draw by hand a network diagram of the project that shows
which activities follow which other ones. This can be tricky. The
analysis method we'll be using requires an "activity-on-arc"
(AOA) diagram. An AOA diagram has numbered "nodes" that
represent stages of project completion. You make up the nodes'
numbers as you construct the diagram. You connect the nodes
with arrows or "arcs" that represent the activities that are listed
in the above table.
CPM
Some conventions about how to draw these diagrams:
• All activities with no predecessor come off of node 1.
• All activities with no successor point to the last node, which has to
have highest node number.
Graphical Evaluation and Review Technique (GERT)
• There is one additional mathematical analysis method that is rarely
used today because it has been proven to be less accurate than
PERT and CPM. This method is the graphical evaluation and review
technique (GERT).
• GERT allows for probabilistic treatment of both network logic and
activity duration estimates.
• GERT is mainly used on project activities that are only performed in
part, as well as those activities that may be performed more than
once (loop). The above graphic illustrates a GERT diagram with a
simple loop.
• For example, on a high-rise development project, the electrical
outlets for each floor may be installed as each floor is completed
instead of waiting for the completion of the entire building. Since
this activity will be performed more than once, using GERT will
enable you to calculate the entire duration of this activity.
PERT chart (Program Evaluation Review Technique)
• There is one additional mathematical analysis method that is rarely
used today because it has been proven to be less accurate than
PERT and CPM. This method is the graphical evaluation and review
technique (GERT).
• GERT allows for probabilistic treatment of both network logic and
activity duration estimates.
• GERT is mainly used on project activities that are only performed in
part, as well as those activities that may be performed more than
once (loop). The above graphic illustrates a GERT diagram with a
simple loop.
• For example, on a high-rise development project, the electrical
outlets for each floor may be installed as each floor is completed
instead of waiting for the completion of the entire building. Since
this activity will be performed more than once, using GERT will
enable you to calculate the entire duration of this activity.
PERT Example
• The Program Evaluation and Review Technique (PERT) is a project
scheduling technique to analyze and represent the tasks involved in
completing a given project. It incorporates activity duration variability
and relies on similar concepts as the critical path method.
Table 1: An example project for PERT calculations
Task
Predecessors
a
m
b
A
none
2
5
8
B
A
1
2
9
C
A
0.25
0.5
3.75
D
B
1
1
7
E
B and C
1
2
9
F
D and E
1
3
11
PERT Example
Activity Duration Estimates
• Activity durations are based on estimates made by human beings
and are therefore error-prone. In PERT, the technique requires
three duration estimates for each individual activity, as follows:
• Optimistic time estimate (a): This is the shortest possible time in
which the activity can be completed, and assumes that everything
has to go perfect
• Realistic time estimate (m): This is the most likely time in which the
activity can be completed under normal circumstances
• Pessimistic time estimate (b): This is the longest possible time the
activity might require, and assumes a worst-case scenario
PERT Example
The project network and the (average) critical path
Tools & Techniques for Schedule Development
Tools & Techniques for Schedule Development
Tools & Techniques for Schedule Development
4. In project management, resource leveling is a technique in which
start and finish dates are adjusted based on resource constraints
with the goal of balancing demand for resources with the available
supply.
Tools & Techniques for Schedule Development
Tools & Techniques for Schedule Development
Outputs from Schedule Development
Outputs from Schedule Development
Outputs from Schedule Development
Outputs from Schedule Development
Schedule Control
Schedule Control
Tools and Techniques for Schedule Control
Outputs from Schedule Control