Critical Path Analysis: Techniques for Project Scheduling

  • from

Image of a maze depicting a projects critical path.

What's on your critical path? Important tasks? Sure. Really important tasks? Of course. But is that all there is to it?  After all, every project task is important in some sense.  Within any project, the critical path is more than just a series of important tasks - it's a means for scheduling and management that relies on connections and consequences as a basis for planning project tasks and timelines.

As a project management technique, critical path analysis provides value in four (4) key respects:

  1. The critical path analysis is a means to estimate overall project duration.
  2. The critical path analysis is a basis to create a logical sequence of project tasks.
  3. The critical path analysis is a means to track project progress and identify delays.
  4. The critical path analysis is a basis to identify potential "fast-tracking" possibilities.

Practical Steps for Critical Path Creation

Critical path tasks are not considered "critical" on the basis of value or visibility, but on the basis of dependencies, which determine the overall length of the project. Since critical path tasks are connected tasks, a delay in one, can lead to a delay in all. As such, once identified, the critical path shows you what how to get your project done on time. 

Read more:  Project Scheduling Strategies

Critical path analysis relies on a few simple assumptions, as listed below:

  • Assumption #1 - Projects are made up of tasks.
  • Assumption #2 - Tasks are combined to form a timeline.
  • Assumption #3 - Within this timeline, tasks are either concurrent (can occur simultaneously) or sequential (one task cannot begin until the predecessor [superior task] is complete).
  • Assumption #4 - Sequential, dependent tasks make up the critical path.

Finding Your "Critical Path"

Critical path analysis begins with a task list, identifying all the key tasks required to complete the project at hand. This task list can be broken down into the following seven (7) key elements:

  • Tasks: Specific work activities.
  • Predecessors: Tasks that must be completed before any subsequent, dependent task can begin.
  • Durations: Task time estimates (from start to completion).
  • Early Start Time: The earliest point in the schedule at which a task can begin.
  • Early Finish Time: The earliest point in the schedule at which a task can finish.
  • Latest Start Time: The latest point in the schedule at which a task can start without causing a delay.
  • Latest Finish Time: The latest point in the schedule at which a task can finish without causing a delay.

From a practical standpoint, critical path analysis is all about creating "breathing room", to identify the tasks that must start and end at a specific point in time, versus those tasks which offer scheduling flexibility. Any worthwhile project management software will calculate critical path for you based on the tasks, dates and dependencies entered, but the logic behind these calculations should not be a total mystery, for it is the human element that must respond to project issues and changes on a daily basis - in real time.

Read more:  Project Management Checkpoints and Fundamentals of the Work Breakdown Structure.

Critical path analysis looks for the earliest and latest points at which tasks can begin and end. The calculation of earliest start times (EST) and earliest finish time (EFT) is used to create the project schedule. The calculation of latest start times (LST) and latest finish times (LFT) is used for schedule management, delay resolution, and fast-track planning.

Learn to Fast Track

When it comes to managing, you need more than one approach to be consistently successful. The way you manage when surrounding conditions are good, is not the way you manage when time is running short, resources are stretched thin and people aren't working together. That's what fast tracking is for - and we can teach you how it's done. Learn More

Calculations: Early Starts and Finishes

EST of tasks with no predecessors = First logical starting point.

EST of tasks with predecessors = Predecessor EFT (Earliest Finish Time).

EFT of tasks with no predecessors = Estimated task duration.

EFT of tasks with predecessors = (Task EST + Estimated task duration).

On the other side of the coin, latest start (LST) and latest finished times (LFT) are backwards calculations, considering the earliest starting point of the first subsequent task, minus the expected duration of the task under calculation. To calculate LST and LFT, you will start with the latest finish time and work backwards to calculate the latest possible start time.

Calculations: Late Starts and Finishes

Step 1 - Finding the LFT (latest finish time):

Considering the estimated "earliest start time" of any subsequent dependencies, what is the latest finish time for this task?

Task LFT = EST of the first dependent task.(Example: LFT of Task 1 = EST of Task 3)

Step 2 - Finding the LST (latest start time):

Considering the identified "latest finish time", what is the latest starting time for this task?

Task LST = (LFT – Task duration).

Example: LST of Task 1 = (Task 1 LFT - Task 1 Duration).


If you're looking for a fast, easy way to achieve project planning success, you'll find it inside the Fast Track Project Toolkit. This unique, informative online course gives you everything you need to become a project leader and fast tracking expert. Here's what you'll learn:

  • How to plan and govern projects using strategic project fast tracking.

  • How to use strategic project fast tracking to save time and make the most of available resources.

  • How to use strategic fast tracking to overcome project constraints and limitations.

  • How to use strategic fast tracking to negotiate with stakeholders and build shared expectations.

  • How to use strategic fast tracking to become a more productive project manager and team member.

Source: Unless noted otherwise, all content is created by and/or for

About Us

Right Track Logo staff writers have experience working for some of the largest corporations, in various positions including marketing, systems engineering, help desk support, web and application development, and IT management. is part of Right Track Associates, proprietors and publishers of multiple web sites including, Fast Track Manage, HOA Board List and more. We started in 2001 and have continued to grow our web site portfolio, Toolkit products, and related data services. To learn more, visit us at Right Track Associates.

ITtoolkit News

Get the Latest ITtoolkit Updates. No Inbox Overload.

we do not sell our list

Subscribe Now
I.T. Service Planning The Service Strategy Toolkit Start For Free

If you'd like to learn how to quickly plan I.T. service strategies designed to meet every goal for technology service alignment, service quality and end-user service satisfaction, the I.T. Service Strategy Toolkit is the right course for you. Brought to you by the publishers of, this self-paced course is easy, engaging and actionable, giving you both how-to lessons and take-action tools. Start for free now!.

Committee Management The Project Committee Toolkit Start For Free

If you'd like to learn how to form and operate successful committees, destined to be more productive and less prone to conflict, the Project Committee Toolkit is the right training course for you. Brought to you by the publishers of, this easy course gives you both the lessons and the tools you need to be a better committee leader and organizer. Start for free now!.

Project Management The Fast Track Project Toolkit Start For Free

If you'd like to learn how to how to streamline project management activities to get work done in less time, using the resources you have, then the Fast Track Toolkit online course is what you need. Brought to you by the publishers of, you'll learn how to 'fast track' every stage of the project management process, from pre-project planning to the post-project review. Start for free now!.