Critical Path

[Armand451]

Hello all,
I have a question on how to show the critical path on a project constructed
with a specific end date. I know how to show all tasks that are technically
critical (defined in my Project by activities that have five or less days of
float), but I do not know how to show the thread from start to finish that
has the least amount of float. Because too many of the activities have more
than five days of float built into them. The schedule was not designed by
using the textbook method of creating activities, estimating their times,
sequencing them, and then determining relationships. So we have a good amount
of float in total, but I still want to be able to show with a click the
Critical Path.

Thanks in advance!
Jordan

 

[Andrew Lavinsky]

Here's an obligatory mention of the fact that this doesn't sound like a good
schedule practice, and really you should be using linkages, etc. That being
said:

1) Create a custom flag field. Display it.
2) Display the float/slack field
3) Manually work through the schedule to identify the critical path,
toggling the flag field to yes for those tasks. Redo periodically as the
schedule changes.
4) Create a filter on the custom flag field, or modify the Gantt to display
those tasks as a different color.

 

[Jim Aksel]

First, I hope you haven't hard coded start or finish dates into the schedule
as that will corrupt a critical path immediately. Clear that problem and
establish correct predecessors/successors.

Change the definition of critical path back to 0 days total slack, display a
flag field and mark those tasks with 0 total slack as critical. You can now
alwasy filter to them.

A better method is to simply filter on Total Slack=0. This is your critical
path, regardless of the setting in Calcutions. In calculations you are just
telling project at what point do you want the field "Critical" to show "Yes".
Your true critical path is Total Slack = 0 if you have correct schedule
logic.

--
If this post was helpful, please consider rating it.

Jim Aksel, MVP

Check out my blog for more information:
http://www.msprojectblog.com

 

[Steve House]

If you have built the plan from the finish date, all tasks will be scheduled
as late as possible that will allow everything to finish by that date.
"Float" is the amount of time a task could be delayed before the project
finish date is affected but with all the tasks ALAP, ANY delay will affect
the project finish and you don't HAVE any float. If by "have 5 days of
float built into them" you mean you have padded the task durations by an
extra five days, Project has no way of recognizing that you've done that or
distinguishing between the portion of the task that is activity and the
portion that is padding. You may think you have float but according to its
definition, you don't. You simply have a project where all the tasks have
inflated duration estimates.

Why are you using a schedule creation tool if you're not going to create the
schedule according the methodology that underlies the tools design? "The
schedule was not designed by using the textbook method of creating
activities, estimating their times, sequencing them, and then determining
relationships." Why not? If you're trying to use critical path
methodology, as your concern with displaying the project's float makes it
sound like you want to do, seems like you should built your schedule
according to its foundation concepts instead of trying to force a square peg
down a round hole.

 

[Armand451]

Thanks for the response. Trust me, I wish we were able to design the schedule
the proper way. The customer demanded that we use this methodology.
DEFINITELY not my recommendation or preference. Hence the reason for the
problem I have now.

 

[Rob Schneider]

Just curious ... who is liable when the project does not deliver to the
schedule?

--rms

www.rmschneider.com

 

[Guest]

Thanks for the response. Trust me, I wish we were able to design the schedule
the proper way. The customer demanded that we use this methodology.
DEFINITELY not my recommendation or preference. Hence the reason for the
problem I have now.

I feel your pain, having been in that situation a few times. The problem
is, that when your client scheduled the project that way, the term
"Critical Path" became meaningless. If the majority, or even a significant
number of tasks have fixed dates, there can be no real CP, although Project
will show one, or part of one. The tasks that show as having 0 Total Slack
are that way by coincidence, and they have 0 TS because of the constraints
on them or on other tasks, not because they're critical. The effect of the
constrained tasks is to create artificial critical paths early in the
project, all obscuring the real one. And no CP past a certain point because
the constraints have artificially created slack where there really isn't
any.

It's hard to explain to a client, that if they give you a lemon and say,
"Take this, and make an apple", it just isn't going to happen.