Let's understand the "Critical path" in PPM

[Rajesh_Singh]

Dear Community Members,

I have collaged information regarding Critical Path; I hope you find it useful—a small topic but very useful.

What is a Critical Path?
As per PMBOK, The Critical Path Method is the sequence of scheduled activities that determines the duration of the project.

To make it simple - "Its longest sequence of tasks in the project."

Why is Critical Path so important?
It is very important because the project's critical path allows the project manager to prioritize which tasks require a greater focus. Task belongs to a critical path can directly impact the project schedule. Any delay in these tasks can impact the project completion date.

Tasks not on the critical path can be delayed without affecting the completion date. 

Let's understand the Critical Path?

Imagine there are 5 projects tasks with below dependencies and durations

Project Task	Dependencies	Duration in Hrs
Project Task 1		10
Project Task 2	Project Task 1	5
Project Task 3	Project Task 1	8
Project Task 4	Project Task 2, 3	4
Project Task 5	Project Task 2,3	12

Now let’s draw the dependencies diagram based on the above table to understand what exactly the Critical path is

Explanation:

• From the above diagram:
• Items 1,2,3,4,5 are Project tasks
• Durations of tasks are in red colour around each task 
• Now, based on dependencies, we have drawn this diagram
• Now let’s sequence the tasks. We see three possible sequences
• • • Sequence 1-2-5 marked in green colour
    • Sequence 1-2-4-5 marked in yellow colour
    • Sequence 1-3-4-5 marked in pink colour
    • Now if we calculate the total tasks duration on each path we get
    • Green sequence gets 10+5+12 = 27
    • Yellow sequence gets 10+5+4+12 = 31
    • Pink sequence gets 10+8+4+12 = 34
    • Hence the Longest sequence is a pink sequence with project tasks (1-3-4-5) because its durations is longest 34 hours than the other two sequences
    • As per the definition of the critical path is the sequence of dependent tasks that form the longest duration
    • Hence pink sequence is a critical path (with project tasks 1-3-4-5)
    • Here Project task 2 do not belong to the critical path

Steps to view Critical path in ServiceNow

• Open any project
• Go to Related Links and click on “Planning Console.”
• On the Planning console at secondary menu bar - Click the critical path icon ()  
  
  

Now let's see how ServiceNow shows the Critical Path?

In ServiceNow – On the Gantt chart, tasks that belong to the critical path is highlighted in red and tasks that do not belong to the critical path are highlighted in blue. 

Please note - not all tasks are part of the critical path.

Now Let’s use the above example with the same 5 tasks, same dependencies and same duration in ServiceNow and see how ServiceNow shows the critical path

• Create Project with 5 tasks and their corresponding dependencies with the planned duration stated in the above example.

• when I click on the “Show Critical Path” icon on the planning console, it shows
• • Project tasks 1,3,4,5 highlighted in red because it belongs to the critical path. 
  • Similarly, Project task 2 does not belong to Critical Path, and it's highlighted in blue.
• Hence Critical path is successfully verified.

[vg47641]

Thank you, it's much clear now.

[Balaji MR]

Thank you for the detailed explanation, makes life easy

[PBNZ]

Hi all, does the critical path get marked on any tables or is it only a visibility thing in the planning console?

I want to know if I can extract the task table or similar from PPM and have a record of the critical path at a moment in time. Baselining helps the moment in time piece, but not the critical path identification record.

Thanks!

[DS14]

@Rajesh_Singh - Do you have any option to create report for critical path project task?

[Rajesh_Singh]

@DS14 - 

Yes, in ServiceNow PPM module, you can create a report for critical path project tasks by following these steps:

1. Navigate to the Project Workspace of the project that you want to create a critical path report for.
2. Click on the "Tasks" tab and select the "Critical Path" view.
3. This view will display all the tasks that are on the critical path for the project.
4. Click on the "Export" button to export the critical path tasks to a spreadsheet or PDF report.
5. Alternatively, you can create a custom report by going to the Reports module and creating a new report based on the "Task" table. In the report builder, you can filter the report to only show tasks that are on the critical path.

I hope this helps you create a report for critical path project tasks in ServiceNow PPM module. Let me know if you have any further questions!

[PBNZ]

Hi @Rajesh_Singh thanks for your quick response. 

Can you please re-confirm how you are getting it to show only the critical path items?

I have the following view in Workspace. I am on the planning tab not task as you have said. Not sure what you meant by that, sorry?

When I click on the three dots to export the plan it exports all tasks, not just the critical path.

I will give the report a go as well. I can find the task table but how do I identify the critical path tasks, as I read elsewhere that the critical column on that table is not to be relied upon?

Appreciate your help :). 

For context - we are looking into this so that we can present a view of Portfolio or Programme level critical path.

[Rajesh_Singh]

@PBNZ 

Apologies for the confusion earlier. Unfortunately, the default "Export" button on the Task list exports all tasks, not just the critical path tasks. However, you can still create a custom report that only includes critical path tasks. You can very much relay on critical field. its data, data can't lie 😛

To identify critical path tasks in the Task table, you'll need to filter tasks based on the "Critical" field.

create custom report on project task table with filter - select the "Critical" field. Set the condition to "is" and the value to "true."

let me know if this works

[DS14]

Hi Rajesh_Singh,

  Please find the below article where ServiceNow is stating that there is no relation between critical_path field and Critical Path display in planning console

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0829052

Do we have any another option to create report on Critical Path display in planning console?

Thanks!!