Negative Slack on deadline?

[greg]

I have set a deadline on an activity for the 20th of August 07. I set this
halfway through the activity was in progress. the finish date is now the 24th
of August 07 and i expect a negative slack value, if my math is correct.
However it seems to go no lower than 0. Does project detail, in terms of
negative values or days behind, for a variance on a deadline, or does it just
highlight you now have 0 days left to delay the finish of the specific
activity. Is the purpose of the slack column to say, you have this amount of
days avaiblie to slip to meet the deadline date. Is there another way to deal
with what I am trying to achieve?

Thanks,

Greg

 

[greg]

btw the colums that i am using are Total Slack and Finish Slack

 

[Jan De Messemaeker]

Is this Project 2007? I reead that the calculation has changed. In 2003
AFAIK you would get a negative value

 

[JulieS]

Hi Greg,

I just did a quick test in Project 2003 and Project 2007. Deadlines in
both products show negative slack if a deadline date is passed. So,
there must be something else going on. I assume your calculation is set
to automatic? What does the late finish for the task show? It should
show the deadline date. Do you have a finish no later than constraint
also set on the task?

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

 

[greg]

its project 2000. I can get negative variances on the baseline variance
finish dates, but i want to set up some key absolute must not finish past
this deadline date for critical design tasks until the end of the year. There
is postivie slack for the shutdown dates which arent till 2008, but for the
design i want to monitor some key activities, to make sure the slack gives us
enough time to prepare for the offshite shutdowns. i was wondering how the
slack is calcualted, it seems to be correct, it just wont show anything below
zero for the one task that isnt meeting the deadline date.

 

[greg]

the task itself is fixed units, effort driven, and there is a finish no
earlier than date which is 7/06/07. As i said before, the deadline is
20/08/2007 and the finish is now 24/08/07. Hope any of that info helps.
thanks

 

[JulieS]

Hi Greg,

Thanks for the update. Sadly I don't have Project 2000 around to test,
but I don't recall the calculation being changed from Project 2000 to
2003. I assume you are seeing the missed deadline flag in the indicator
column. What does the late Finish date for the task show?

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

 

[greg]

These is an exlamation mark in the identification column saying that the task
finish dates is not meeting its deadline. The late Finish is the same as the
Finish, both are 16/10/07. Does this matter? It was an activity that was in
progress, so unless there are some issues with putting deadlines on for in
progress tasks? I was going to re-enter the task information.

Thanks for the help

 

[greg]

the reason i think it may be this, is that there is negative slack on two
other activities that are not meeting their deadline dates, and these have
not started, not in progress. that is the only thing i can assume it may be.

 

[JulieS]

Hi Greg,

Sorry, even with progress (tracking) added to a task, I still see
negative total slack if the task is projected to miss its deadline.
Again, I am testing using Project 2003, so I can't say wheather this is
a 2000 issue. Have you tried to add progress against one of the other
tasks that you say has negative total slack?

If all else fails, perhaps your plan of just recreating the task is
best. Sorry I couldn't pinpoint the problem for you.

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

 

[greg]

Hey Julie,
thanks for the reply. Here is where it gets wierder. I have copied and
pasted one of the tasks that was displaying 0 slack even though it was well
passed the deadline. I 0% the task, and then applied the same progress, split
that task, made sure no constraints were on and it worked. Its now showing -
7 days. But when i went to the other one, i tried the same process and it is
still showng 0, not any lower. I have tried creating an entire new activity
and setting it up again, copying the task that worked above and chaning the
progress - it has some actual work, a long split and then a long remaing work
bar, it still stops at 0. For this one activity, bizarre, anyways i will keep
playing around with it. They have the same settings, same calendars, no
resources assigned.

 

[greg]

it shows negative slack if i have a deadline of the 10th of july or earlier
(should be the 3rd of septemeber. Anything after that, it just goes 0.
Strangely, this is where the remaining split work starts, after the 10th of
july, could this be where the issue is?

 

[JulieS]

Hello greg,

Thanks for the additional information. Sorry, even with splits, tracked
work, etc. I can't reproduce. If you would like you can zip the file
and email it to me. It's likely I still can't come up with a magic
answer but at least we can see if it still occurs in Project 2003. My
email address is

passport 6847 AT maine dot rr dot com

remove spaces and conver at to @ and dot to .

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