An idiot's guide to Critical path method ( The algorithm which drives most of the scheduling and project management software)

1. Skills for delivering with certainty
Introducing
Critical Path Method

2. Agenda
• Recap.. 5 mins
• Dependencies
• Activity Box
• WBS with estimate
• Forward Pass
• Reverse Pass
• CPM and float

3. Can you tell when the project will get over

4. Dependency

5. Project value versus cost

6. Project value versus cost

7. Project value versus cost

8. Critical Path method

9. History
• CPM is a project modeling technique developed in the
late 1950s by Morgan R. Walker of DuPont and James
E. Kelley, Jr. of Remington Rand.[2]
• ”Critical path" coined by Booz Allen Hamilton and
the U.S. Navy.[4] during Manhattan Project.
• CPM used with all forms of projects, including
construction, aerospace and defense, software
development, research projects, product development,
engineering, and plant maintenance, among others.
Any project with interdependent activities can apply
this method of mathematical analysis.

10. Manhattan Test
The Manhattan Project was a research
and development project that produced
the first atomic bombs during World War
II. It was led by the United States with the
support of the United
Kingdom and Canada. From 1942 to 1946,
the project was under the direction
of Major General Leslie Groves of the U.S.
Army Corps of Engineers; physicist J.
Robert Oppenheimer was the director of
the Los Alamos National Laboratory that
designed the actual bombs

11. Project : Secure a plot

12. An activity Block
Early Start
Late FinishLate Start
Early Finish
Activity Name
Duration = 8 days
Float = ?

13. 3 kinds of dependencies and reasons:
Causal (logical)
It is impossible to edit a text before it is written
It is illogical to pour concrete before you dig the foundations
of a building
Resource constraints
It is logically possible to paint four walls in a room
simultaneously but there is only one painter
Discretionary (preferential)
I want to paint the living room before painting the dining
room, although I could do it the other way round, too

14. Some Definitions
Float : The amount durational flexibility in any activity without
affecting the overall duration of the project. Its computed as a
difference between Early Finish and Late Finish or Early start and
late start = EF-LF= ES-LS

15. Some Definitions
Drag : It is the maximum amount of time that one can shorten the
activity before it is no longer on the critical path or before its
duration becomes zero. Its computed by : Least float of a parallel
activity

16. Some Definitions
Lead : How much duration before end of predecessors can we
begin an activity
Lag : How much of gap we have after end of predecessor for us to
start the task

17. A typical solution

18. What’s Your Message?
CPM is the algo for
project mgt software