web analytics
Skip to content
Critical Path vs Critical Chain

Critical Path vs Critical Chain

If you enjoyed reading this post, check out all of our post on PMP Concepts Learning Series.


Designed to help those that are preparing to take the PMP or CAPM Certification Exam, each post within this series presents a comparison of common concepts that appear on the PMP and CAPM exams.

Critical Path vs Critical Chain

Critical path and critical chain are both methods of project scheduling.

Critical Path

The critical path method calculates the early start and finish dates and late start and finish dates for all schedule activities.

The critical path method involves performing a forward pass analysis and a backward pass analysis through the project schedule network paths. The forward pass determines the early start (ES) and early finish (EF) dates (ES + duration (DU) = EF). The backward pass determines the late start (LS) and late finish (LF): (LF – DU = LS).

The critical path is the longest path through the schedule with either zero or negative total float.

Critical activities are those schedule activities on the critical path. Near-critical activities are those schedule activities with very little total float.

Critical Chain

The critical chain method is a technique that modifies the project schedule to account for limited resources by adding duration buffers that are non-work schedule activities to maintain focus on the planned activity durations.

Critical chain is completed after determining critical path by entering resource availability and the resulting schedule produces a resource-constrained critical path, which is usually altered from the original. Critical chain focuses on managing remaining buffer durations against the remaining durations of task chains.


The critical path method (CPM) is a popular approach to project scheduling that considers the amount of float on project activities. Critical chain takes CPM a step further by adding time buffers to account for limited resources.

See all posts in our PMP Concepts Learning Series


  1. Ilanit Meckley on July 3, 2017 at 12:25 pm

    best explanation i’ve heard on the critical chain method yet!

    • Don Hyde on October 4, 2017 at 7:28 am

      I agree. Others attempt to simplify the explanation but this helped me understand at least for test taking purposes!!

  2. Shekhar Kulkarni on August 9, 2018 at 11:14 am

    Great Explanation!! PMBOK does not explain it quite this clearly.

Leave a Comment

PM Learning Solutions

  2550 W Union Hills Dr

Suite 350-302

Phoenix, AZ 85027

  (888) 871-PMLS (7657)

  Mon - Fri | 9:00 - 5:00 MST