The Two-Pass Technique

In schedule management, one of the scheduling approaches to develop a project or program schedule is the Critical Path Method (CPM). This is one of the oldest and widely used scheduling methods. The CPM determines the shortest possible time the project can complete, along with the end date of the project.

The main way to determine the critical path is by using the forward pass and backward pass technique. This is also known as the two-pass technique. With this method, one can find out the early start (ES), late start (LS), early finish (EF), and late finish (LF) for every activity. This method also determines the total float (TF), which informs about the flexibility of schedule. This helps any management practitioner, because, with this technique, you can also determine the flexibility of individual tasks/activities and can assign, replace, and add resources based on the demand of the project or program. For example, a new resource can be put into an activity, which has high flexibility (i.e., a high total float (TF) value).

The advantage of using MS Project is that it auto-calculates everything for you: ES, LS, EF, LF, the critical path, and the TF. This is highly useful as schedules changes over the course of a project/program. It’s also possible that you may have constraints added, removed, or modified into the project, which will impact these values. The software re-calculates these values.

There are multiple ways to calculate the critical path and the values related to forward and backward pass techniques, but MS Project calculates them in a very specific way.

In my on-demand webinar, we explore:

  • How to conduct forward pass and backward pass calculations
  • How to determine the total float for the activities
  • The significances of total float, ES, EF, LS, and LF?
  • How Microsoft Project software address the two-pass technique
  • How Microsoft Project determines total float

Watch the session on-demand.


Share This Post
Avatar photo
Written by Satya Narayan Dash
Satya Narayan Dash is a management professional, coach, and author of multiple books. Under his guidance, over 2,000 professionals have successfully cracked PMP, ACP, RMP, and CAPM examinations – in fact, there are over 100 documented success stories written by these professionals. His course, PMP Live Lessons - Guaranteed Pass, has made many successful PMPs, and he’s recently launched RMP Live Lessons - Guaranteed Pass and ACP Live Lessons - Guaranteed Pass. His web presence is at, and he can be contacted via email at  

Leave a Reply