PERT Diagram & Gantt Chart
PERT- Program Evaluation and Review Technique.
PERT has been in usage since the 1950s and PERT
diagrams are popular project management tools
and it also most popular in the fields of business
management and quality control. PERT was -
developed primarily to simplify the planning and
scheduling of large and complex projects. It was
developed for the U.S. Navy Special Projects
Office in 1957 to support the U.S. Navy's Polaris
nuclear submarine project.
PERT diagrams show precedence, activities
that mustbe completed before the next activities
may be started.
Used to calculate the critical path or the longest
path through the activities.
This is the shortest time to complete the project.
PERT Diagram Example:
Activity Time(day) Require Predecessor
A 4 None
B 3 None
C 2 A
D 1 A
E 1 B
F 2 B
G 3 C
H 2 D, E
I 2 F
J 2 G
We have four (4) way to find critical path.
1. A+C+G+J = 11
2. A+D+H = 7
3. B+E+H = 6
4. B+F+I = 7
So critical path is, A+C+G+J = 11
And time of complete the project is 11 days.
Free slack is = Value of start point of critical path –
value of start point of others non critical path.
A – B
= 4 – 3 = 1
PERT Diagram Advantages:
1. Easy identification of the order of precedence.
2. Easy identification of the critical path and thus
3. Easy determination of slack time.
Gantt Chart :
Gantt chart a chart in which a series of horizontal lines
shows the amount of work done or production
completed in certain periods of time in relation to the
amount planned for those periods.
It is easy to construct and use.
Shows activities over a period of time
Fig : Gantt chart of given PERT diagram .
1 2 3 4 5 6 7 8 9 10 11