Total Slack index for last task

[yair o]

Hello,
When adding a deadline to the last task in the project that's later than
the task's finish date, I've seen different behaviors between the default
project opened when entering the PP (project1) and the one opened from a
project template.
The default project eliminates the critical path and shows a positive total
slack while the project opened from template still shows a critical path and
total slack=0.
I haven't found any place to define this behavior – do you know of any?
I'm aware of the Total slack's meaning. My question is only about the last
task in the project.
Thanks in advance
Yair

 

[JulieS]

Hi Yair,

Well, this is a puzzler. The first behavior you describe (setting a
deadline after the scheduled finish of a task and seeing total slack on
that task) is normal behavior for Project. Setting deadlines changes
the Late Finish date for tasks and does affect Total Slack calculation
and critical path.

The display of critical path in the Gantt chart view can be modified by
changing the definition of critical tasks on the Calculation tab in
Tools > Options. If you set the option for "Tasks are critical if slack
is less than or equal to X days" that will change the *display* of
critical path in the Gantt chart view. However, it does not change the
calculation of Total Slack, you will still see positive values.

About the only way I have seen to even begin to replicate the issue you
are seeing is to schedule the project from a fixed finish date (Project

Project Information). I created a project with a finish date of 20

October 2006, added four tasks (A, B, C, and D) with one day duration
and linked them all Finish to Start. As expected, finish date of task D
is 20 Oct 2006.

I then set a deadline on task D of 23 October. A warning appears from
the Planning Wizard about moving the task after the finish date of the
project. When I chose to move the the task after the project finish
date, the task's finish date changes to 23 October 2006. Total Slack is
zero. The odd thing is that if I view the Project Finish date through
Project > Project Information, the date is still 20 Oct 2006, despite a
task finish date of 23 October 2006.

I don't know if this is a *possible* explanation for what you are
seeing, but, I hope this helps. Let us know how you get along.

Julie
Project MVP

Visit http://project.mvps.org/ for the FAQs and additional information
about Microsoft Project

 

[yair o]

Hi Julie,
Thanks for your reply.
All my customers schedule their projects from project start date and not
from finish so your offer does not help me. The definitions in Tools -->
Options are also irrelevant for my problem.
I would like to see TS for the last Milestone of the project compared to its
deadline. I've tried adding a dummy task at the end of the project, but also
encountered different behaviors of TS for different situations. I need to
understand the exact logic of MSP for this last task, what's expected to
happen and also create a comprehensive workaround. Any help or ideas would be
appreciated.
I can mail you the examples if you like...
Thanks
Yair

 

[JulieS]

Hi Yair,

Sorry the scheduling from finish date didn't solve the issue.

If you would like, go ahead and email me a sample of what you're seeing
in the project created from the template that exhibits the unusual
behavior.

My email address is:
passport 6847 at maine dot r r dot com

remove the spaces and replace "at" with @ and "dot" with .

I hope this helps. Let us know how you get along.

Julie
Project MVP

Visit http://project.mvps.org/ for the FAQs and additional information
about Microsoft Project

 

[yair o]

Hi again,

Regardless of the reasons for the problem, the manual solution I've found is
to add a DUMMY task at the end of the plan that has a "must finish on"
constraint with the date of deadline of the last milestone.

 

[yair o]

Another solution is to outdent the last milestone all the way left to outline
level 1.