MANAGING PROJECTS

Managing Projects

Managing Projects

Task 1

The network diagram

Activity

Duration

Start Date

End Date

Proceedings

A

4 days

Wed 03/7/11

Mon 03/12/11

 

B

4 days

Tue 03/13/11

Fri 03/16/11

1

C

1 day

Tue 03/13/11

Tue 03/13/11

1

D

1 day

Tue 03/13/11

Tue 03/13/11

1

E

1 day

Tue 03/13/11

Tue 03/13/11

1

F

5 days

Mon 03/19/11

Fri 03/23/11

2,3,4,5

G

6 days

Mon 03/26/11

Mon 11/2/11

6

H

2 days

Mon 03/26/11

Tue 03/27/11

6

I

2 days

Mon 03/26/11

Tue 03/27/11

6

J

7 days

Tue 04/3/11

Wed 04/11/11

7,8,9

K

6 days

Thu 04/12/11

Thu 04/19/11

10

L

3 days

Thu 04/12/11

Mon 04/16/11

10

M

2 days

Thu 04/12/11

Fri 04/13/11

10

N

8 days

Fri 04/20/11

Tue 05/1/11

11,12,13

O

10 days

Wed 04/2/11

Tue 05/15/11

14

P

2 days

Wed 04/2/11

Thu 05/3/11

14

Q

10 days

Wed 04/16/11

Tue 05/29/11

15,16

R

10 days

Wed 04/30/11

Tue 05/12/11

17

Timing of Activities and Total Float Calculation

D = Duration

ES = Earliest Start Earliest finish time of preceding event

EF =Earliest Finish EF = ES + D

LS =Latest Start LS = LF - D

LF =Latest Finish LF = LS + D = Latest start time of following event

TF=Total Float TF = LF - EF = LS - ES

FF =Free Float FF = ES (following activity) - EF (this activity)

TF =Time activities' start or finish can be delayed without delaying project completion.

FF =Time single activity's finish can be delayed without delaying the ES for a following activity.

Project Duration and the Critical Path

Steps in CPM Project Planning

1. Specify the individual activities.

2. Determine the sequence of those activities.

3. Draw a network diagram.

4. Estimate the completion time for each activity.

5. Identify the critical path (longest path through the network)

6. Update the CPM diagram as the project progresses.

Specify the Individual Activities

From the work breakdown structure, a listing can be made of all the activities in the project. This listing can be used as the basis for adding sequence and duration information in later steps.

Determine the Sequence of the Activities

Some activities are dependent on the completion of others. A listing of the immediate predecessors of each activity is useful for constructing the CPM network diagram.

Draw the Network Diagram

Once the activities and their sequencing have been defined, the CPM diagram can be drawn. CPM originally was developed as an activity on node (AON) network, but some project planners prefer to specify the activities on the arcs.

Estimate Activity Completion Time

The time required to complete each activity can be estimated using past experience or the estimates of knowledgeable persons. CPM is a deterministic model that does not take into account variation in the completion time, so only one number is used for an activity's time estimate.

Identify the Critical Path

The critical path is the longest-duration path through the network. The significance of the critical path is that the activities that lie on it cannot be delayed without delaying the project. Because of its impact on the entire project, critical path analysis is an important aspect of project planning.

The critical path can be identified by determining the following four parameters for each activity:

ES - earliest start time: the earliest time at which the activity can start given that its precedent activities must be completed first.

EF - earliest finish time, equal to the earliest start time for the activity plus the time required completing the activity.

LF - latest finish time: the latest time at which the activity can be completed without delaying the project.

LS - latest start time, equal to the latest finish time minus the time ...