Skip to Main Content
Skip to Navigation
Project Management Orientation

Applying the Backward Pass 

The backward pass is used to calculate the LS and LF dates of all network activities.  These are the latest dates these events can take place without affecting the finish date of the project.
  
For this example, assume that the LF of the activity following Pour Concrete is 15.  To calculate the LS of Pour Concrete, take 15 and subtract 4, the duration of the activity, to get 11.
  
The LS of Pour Concrete is the LF for Mix Concrete.  To calculate the LS for Mix Concrete, subtract the duration from the LF: 11 - 6 = 5.  This means that Mix Concrete can start as late as day five without affecting the finish date of the project.
  
The LS calculation is LS = LF - duration.

Note that in the last activity of the project
the EF is the same as the LF.  Using that
LF, you can start the backward pass. 

Also note that the LS and LF numbers do
not equal the ES and EF on the bottom
path.

Example of Backward Pass
1: Getting Started
2: Define the Project Team
3: Team Management
4: Identify and Validate Requirements
5: Create Decomposition Structures
6: Risk Management
7: Project Estimates
8: Project Schedules
9: Change Management
10: Project Control and Execution
Defining the Project
11: Project Management Review
12: Project Closeout
13: Project Management Tool Suite
14: Self-Assessment and Final Exam
Fast Points
Concepts
Seven Keys
Case Study
WWPMM
Mentor
Check Point
Previous button
Next button
Print button
Help button
Glossary button
Exit course button