Not sure how to show the Critical Path in Primavera P6? Not sure if your project’s critical activities might be hiding?
Don’t worry. Here are 4 easy ways you can laser-in on your project’s Critical Path in P6 (including 3 reasons you might not have one).
4 Easy Ways to Show the Critical Path in Primavera P6
1. Check the Gantt Chart
By default, the P6 Gantt chart will show your project’s Critical activities in bright red. This makes it easy to have a quick glance at the Gantt Chart et voila!, your Critical Path stands-out like a construction safety vest.
I don’t see any red activities on my Primavera P6 project. How can I fix it?
Glad you asked. 😉 Maybe your Gantt chart looks like this instead, with no red activities highlighted at all. Where is your project’s critical path, you might wonder?
Primavera P6, by default, uses Total Float to decide if an Activity is Critical or not. Activities with a Total Float value of 0 (or less) usually show up red on the Gantt.
#2 Use the Critical and Longest Path Columns
Edit your columns and go digging for one called “Critcal” and another called “Longest Path”. Add one or both of these nifty columns to your Activity Layout to show clearly which activities are Critical.
#3 Turn On a Filter
Using a Filter can also be a quick and effective way to manifest your Critical Path. Click the Filters button to turn on the Critical filter. This will show only the Critical Activities. There’s also a filter for the Longest Path.
#4 Check the Schedule Log
Lastly, you can always check the P6 Schedule Log. The Schedule Log is a log file that gets updated every time your project is scheduled. Press F9 and make sure the box labeled “Log to File” is checked on. Then, click the “View Log” button to open the Schedule Log.
Once you have the log file open in Notepad, you’ll have to scroll down to the section labeled “Exceptions”. But you should see in the log a list of your project’s Critical Activities.
3 Reasons you Can’t Find Your Critical Path in Primavera P6
If you have tried the 4 ways above but still are having no luck seeing your project’s Critical Path on the Gantt chart, then these 3 common situations might be happening.
Reason #1 No Critical Path due to Poor Relationship Linking
A common reason for Primavera P6 users to not have any critical activities on their Gantt chart is due to poor relationship or logic linking.
A project schedule is a network of activities where the relationships act as the connectors. If your relationship linking was poorly done, then Primavera P6 will not be able to calculate a critical path and will not show you any Critical activities.
Poor relationship linking means the following:
- missing links or open ends – all activities are not linked to eachother in a resonable fashion, creating gaps in the network
- circular logic – activities are linked in such a way that they link back to their predecessors, instead of forward to their successors
- irrational logic – activities are linked using varying types of logic that makes no sense (ie: using only Finish-to-Finish relationships or misuing Start-to-Finish relationships)
READ: How to Build A Cringe-Worthy Primavera P6 Schedule
Reason #2 An Overuse of Date Constraints
Dates constraints will affect how CPM is calculated by Primavera P6 and can result in no critical activities on the Gantt Chart.
Using too many date constraints, and especially P6’s mandatory date constraints may result in no critical path being calculated.
Setting too many “Start On” constraints or “Finish On or Before” constraints can definitely have detrimental effects on your project’s CPM calculations.
I always recommend using constraints as infrequestly as possible to avoid having constraints interfer with Primavera P6’s network calculations.
Reason #3 Project Finishes Earlier Than Must Finish By Constraint
Often planners set a “Must Finish By” date on the entire project. Must Finish By in Primavera P6, is a special type of constraint that is set on the entire project, rather than on a single activity.
You may have a Must Finish By date set on your project. If your project is finishing earlier than the Must Finish By deadline, then you may not have any activities with 0 or less Float values which means there are no Critical activities by definition.
If that’s the case, tell P6 to show Critical Path by the Longest Path rather than by Total Float (in fact, Longest Path is preferred)
- Press F9, and then click the Options button.
- Find the setting “Define Critical Activities as”. Choose Longest Path.
- Reschedule your Project.
- Check the Gantt chart now. You should see a red path of critical activities now.
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This post was originally published Dec 9, 2013 and has been updated since
Excellent lesson.
Thanks Marcus!
I’ve just tested the review of the Longest Path in P6 R7, and it would appear that the use of Level of Effort tasks completely renders the Longest Path calculations useless. LOE tasks and the final milestones are the only tasks which appear. Pity for those of us who use LOE tasks.
I have used Level of Effort with P6 EPPM 8.2 many times. It gives the LOE activities a duration dependant on other activities and removes te LOE activities from the critical path. However, they can be on the longest path. This makes sense to me, but I wouldn’t mind it if the LOE activities stayed off the longest path.
good lesson
thanks
Good, snappy points.
On point two there may be a constrained milestone as the project finish a little (or not) after the latest finishing activity
Thanks, Michael. I learned something new.
@Matt,
Strange – are there any lags in your LOE relationships by chance? I did some testing and I did find that my LOEs were on the Longest Path (not completely sure why). Are the tasks that your LOE is summarizing not on the Longest Path?
Sir
Using Mutiple Folat path can you say me how to show number of Longest Paths in the Schedule that affect Project Completion Date .
Jody, good point to ensure we may have a Must Finish By date set on your project or that the project is finishing Earlier Than the Must Finish By deadline
Dear Mike,
In the figure attached with item 2, we find the items marked as in the Longest Path, are not Critical. Is it possible for activities in the longest path not to be critical?
@Jose, yes and no. The screenshot in 2. shows which activities are Critical by the Total Float method (Critical column) and which activities are Critical by the Longest Path method (Longest Path column).
Over here https://www.plannertuts.com/article/critical-path-vs-longest-path/ I explain that the Longest Path is a Critical Path, but not all Critical Paths are the Longest.
What is happening is that there are 2 ways to define what’s Critical. Yes, some activities on the Longest Path may not be considered Critical by Total Float. Thus, I recommend being aware that this is the case and being aware of the Longest Path.
M
tnx michael it was good
Please can i have any plan in primavera contact me by s6eefalqwasmah@gmail.com please i have a homework (any subject by primavera)
Dear Mike,
Your lesson about critical path is really useful. But i have just one question. Can the Primavera programm calculate the duration of critical path or i have to do that manually. I cant find any command at P6. My definite target is to calculate the variance of Critical Path duration between the CP duration before and after levellling.
Thanks in advance
Hi Marios,
Put on the Critical filter, and make sure you have Grouping set to WBS. The Duration at the very top is the Duration of the Critical Path. To see the variance, you could create a baseline of your project before leveling. Assign the baseline to the project. Then, add a column to your view – “Variance – BL Project Duration”. This will be the variance after leveling.
M
Thank you very much for your reply. I wasn’t sure about the duration while filtering the project by critical path.
thanks, this super clear directions.
Thank you Mike, Your lessons as usual are right to the point and are always unique and cannot be find anywhere else for FREE.
Thanks Alex! We aim to be uber helpful!
Michael
Those activities which has constrains as mandatory start showing as critical activity,why?
Rajaram,
It’s probably because the mandatory constraint is forcing an activity to a date earlier than the network logic – thus breaking the network logic. The result is negative float on the mandatory activity causing it to be critical.
It’s a general consensus not to use mandatory constraints on any project. As they break the network logic, the integrity of your project’s logic is gone….and only with good logic can you have / track / manage your critical path. With broken logic, the critical path is uncertain.
The proper approach is to use non-mandatory or soft constraints and to monitor their effect on Total Float.
Hope that helps.
Is there any Problem with this kind of Critical Path??
Hi Michael,
Due to many dependent activities and other conditions at site. schedules are not followed by the team as per the Base plan.
There are so many delays in schedule.
Kindly advice how to recover the delay by means of recovery plan / recovery schedule.
Jyothi
Jyothi, it’s pretty apparent that you will have to revisit all remaining work and re-plan it to build a recovery schedule. Look at your critical path and see if it makes sense. Work with contacts in the field to see if you can get the schedule to accurately reflect how the work will be produced. Talk to supervisors about the using the schedule daily – get support from management. It’s going to be a tough job, one that likely very frustrating. But the schedule is important.
i added activities to the WBS but i cant view all the activities but some.it is only the WBS showing.please what can i do to view the activities
Not sure – turn off any filters you have on.
Go to Group & Sort
Uncheck the dialogue box “Hide if Empty”
I remove the project end date from the schedule and then use the filter
best regards
There’s another possibility. If different calendars have been assigned to different activities, Primavera might not consider some activities with zero float as critical. Probably because the float is calculated in days while difference in calendar could be in hours (e.g. difference in workhours). It just happened to me.
Hey Michael,
Every activity in my plan has got zero float and hence primavera is showing every activity as critical activity, Do you have any solution for this.
P.S- I haven’t assigned resources yet.
Yes of course – 0 float means it’s a critical activity based on the P6 criticality filter. Try this. Press F9 (schedule) click options, select Longest Path as the option to define critical activities.
How can I filter Resource assignment that are only assigned to activities on the critical path? I want to develop critical path S-curve
The only approach I can take to generate critical path s-curve is to assign resources to all activities on the critical path and use resource assignment weight to generate critical path s-curve. is there any other way?
Kind regards
Rephinus
Assign resources to all activities as normal – I assume you’re resource-loading your schedule. Go into Filters and turn on the Critical filter so only your Critical Path shows. Then goto View->show on Bottom ->Resource Usage profile and configure the graph to show your s-curve (cummulative curves).
Excellent
Go Ahead
Hi Michael,
I am preparing a schedule for a land development project. My client has the master schedule, and mine has design, tenders, and construction administration services for the specific sites.
In the client master plan, they planned to do some of tender& construction works related to our sites, in 2020 and the rest in 2021.
My schedule now is broken. Between completing design phase and some tenders I have 1 year pause. As a result I a lot of float and there is not one critical path. Also, wondering how can I get rid of a few constraints I had to put for external inputs.
What do you suggest?
Mary, this sounds a bit complex to be able to grasp and reply in a comment form. Feel free to reach out to our office.
Hello Michael Lepage,
How to remove unnecessary activities in critical path, Basically which are not critical activities ?
If they are on the Critical Path, how do you know they are not critical and need to be removed? Seems like maybe you have your own definition of critical path.
You don’t remove activities from your critical path. If you have incorrectly linked an activity, and it shows up on your critical path, then correct the links. But accept that all activities on your critical path, are critical.
Hi Michael,
Thank you for your knowledge sharing.
How P6 calculate Early Start & Late Start in order to calculate Total Float for each activity?
I think some of my activities have Total Float incorrectly and I don’t know why !
Can you help me?
Hi Navid,
The CPM Scheduling 101: How Primavera Scheduling Works blog post may help.
Regards.