i can’t tell without seeing the network, but it’s not difficult to figure out.
1) determine how many paths there are through the project from the 1st activity to the last one.
2) add up the durations of the activities on each path to calculate the total duration of each path.
3) the longest path is the critical path.

pls. from my network diagram am having
from start
path a-c-e =15 days
path b-d = 20
path b-d-e = 27
path a-d-e = 22
path b-c-e = 20

which is the critical path?

create a filter to hide the offending activity.

as for which path to choose, one must understand the culture the schedule is created in. after 25 years of working in the near and middle east among many cultures what ravi has stated is very common. the name of the game in many cultures over there is to hide perceived failure and point fingers for blame. if ravi was to try to explain anything to management, he would under the best managers be told to just go do it. under most managers he would be sent packing back to his home country and replaced. the fact he shows negative float tells me he has a constraint on the schedule somewhere that he was ordered to place. most managers are either blissfully ignorant or honestly don’t care of what and how a schedule works. until that changes, scheduling in the east will always be difficult. ravi may be a good scheduler, but he will never be allowed to practice it in most cases.

i highly recommend you take time to explain the full meaning of what your schedule shows. scheduling is complicated, and negative total float doesn’t need to be taken as a failure.
explanation and education is key. education your team on the implications of the schedule.
transparency takes courage but it’s more valuable than knowing how to maneuver the software to your advantage.

hi ravi. have you found the way to hide this and how do you act in such a situation? thank you. i come to the same situation.

you can identify near-critical paths by analyzing total float of your activities. if an activity isn’t on the cp it might be near-critical if it has a small total float. you can use the multiple float paths tool in p6 to do an in-depth analysis (too complex to explain here) but that’s no guarantee. as you progress, your cp will split and diverge, often to near-critical activities, but elsewhere as well. i recommend monitoring activities with small float, near-critical, to predict where it may go.

hi khaja, when a schedule has actuals, those completed activities are no longer critical nor can they be on the critical path. this is a basic rule of cpm scheduling – only the remaining work will be on the critical / longest path.

in a schedule with actuals, the longest path is not starting from the baseline start date.

is it due to out of sequence activities? please reply here and mail to my email id also.

thanks a lot.

jim, the longest path is actually calculated by totaling up durations of all the paths through the project. the longest one is the longest path.

the comment that items may seem critical to me but not the customer is a bit confusing because the project scheduler doesn’t usually “own” the schedule. if a task is determined to be critical and not on the critical path then it seems that the logic is wrong and needs to be adjusted.

sonali had an interesting question about how to find the critical path from a completed project. it seems the best way to find what was the critical path from a completed project would be to simply remove the actuals and move the completion must finish on constraint back two weeks and follow the lowest total float.

brian/major, agree that multiple calendars can mess up cp when using total float – i have yet to prove it with an example, but many experts have rumbled about this issue. in case you’re interested in finding the truest critical path, there’s another post i’ve written about it here: primavera p6’s longest path conundrum (and how to fix it) //www.deco-dalles.com/primavera-p6-longest-path-conundrum/

i agree with major, if the activities in your schedule have multiple calendar assignments (5-d ww,
7-d ww) or you are implementing the use of resource calendars, the “longest path” is the better choice due to critical activities having different total float values.

thank you very much for your response. one more question: where i can find that entire project is set for must finish date? project end milestone do not any constraint.

you might have a must finish by date set on the entire project.

one of my project schedule is totally completed. all actual dates are fed in. now, i want to find out what was the longest path in actual scenario. how to find it?

rgds.

1) can there be more than one longest path within one simple project ?
2) can there be more than one critical path in a simple project ?
3) does the longest path always start with the first planned activity in the schedule and ends at the last planned activitiy ?
4) how does the algorithm for the longest path work ? does it also look at total or free float of an activity ?
5) the ‘path’ part is still unclear for me. for my understanding a critical path is always a connected path of activities which satisfy a certain criterion ( for example tf ,= 0 )
how do we cope with 10 activities chained after each other, all with total float = 0, except for 2 activities in the middle due to some constraint or a different calendar. are all 10 activities then considered to be on the critical path, because they are connected or will the 2 activities with a positive tf value be excluded ? when they are excluded, we don’t have a path anymore, right ?

our pleasure!

@ michael – how we have to act in such a situation.