Slack

The difference between the latest and earliest times of any event is called 'slack'. Since each activity has two events, a beginning event and an end event, it follows that there are two slacks for each activity. Thus the slack of the beginning event can be expressed as TLB - TEg and called beginning slack and the slack of the end event, appropriately called end slack, is TLe - TEe. The concept of slack is useful when discussing the various types of float, since it simplifies the definitions.

Table 21.1

Title

Activity

Duration, D

Latest time end event

Earliest time end event

Earliest time beginning event

Duration, D

Latest time end event

Earliest time end event

Earliest time beginning event

A

1-2

3

3

3

0

0

0

B

2-3

5

8

8

3

0

0

DUMMY

2-5

0

11

3

3

8

0

C

3-4

2

10

10

8

0

0

E

3-6

3

13

11

8

2

0

F

4-7

4

14

14

10

0

0

D

5-6

2

13

11

3

8

6

G

6-7

1

14

14

11

2

2

Column a: activities by the activity titles.

Column b: activities by the event numbers.

Column c: activity durations, D.

Column d: latest time of the activities' end event, TLe .

Column e: earliest time of the activities' end event, TEe .

Column f: earliest time of the activities' beginning event, TE^.

Column g: total float of the activity.

Column h: free float of the activity.

Column a: activities by the activity titles.

Column b: activities by the event numbers.

Column c: activity durations, D.

Column d: latest time of the activities' end event, TLe .

Column e: earliest time of the activities' end event, TEe .

Column f: earliest time of the activities' beginning event, TE^.

Column g: total float of the activity.

Column h: free float of the activity.

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

Get My Free Ebook


Post a comment