Help with SF Dependencies

[Ian]

I know I should know this, but...

I am scheduling backwards from a known end date. Task B is 1 day in
duration, starting at 8:00 AM on Monday and ending at 5:00 PM on Monday.

I need task A to start at 8:00 AM on Friday and end at 5:00 PM on Friday.
When I do a SF dependence of A on B, Project has A start at 8:00 AM on Friday
and end at 8:00 AM on Monday (of course, exactly matching the start date of
B).

I have tried 1 minute lags and leads with no success. Can someone give me
the obvious answer, please?

Thanks very much.
///Ian

 

[Jim Aksel]

Project/Project Information....
Set Project Finish Date: Monday 10 SEPT 2007 5:00 PM
Set Schedule From: "Project Finish Date"
Click OK.

Gantt View:
Enter:
Task A 1 day shows start/end on 10 SEPT
Task B 1 day shows start/end on 10 SEPT

Link A to B. A is the predecessor to B with a Finish-to-Start relationship
(FS) which is the default. Use of SF is not required.

Task A now starts 07 SEPT 2007 0800 finishes 500PM
Task B starts first thing Monday morning.

If you like, Tools/Options/View (tab) select the date format to include time.

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Jim
It''s software; it''s not allowed to win.

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

 

[Ian]

I'm sorry, perhaps I was not clear. I need task B to happen on a particular
day. I am not trying to find out when the project will finish - I know the
day it needs to end and I am planning backwards to find out when other things
need to happen to enable that end date.

Task B has a fixed date constraint. I need the previous tasks to have
flexible contstraints so I know when they need to start/end to get me there.

So, if I have Task B with a fixed date, starting at 8:00 AM on Monday and
ending at 5:00 PM on Monday, I need Task A to start at 8:00 AM on Friday and
end at 5:00 PM on Friday.

Thanks for the help.
///Ian

 

[Jim Aksel]

Project/Project Information -- schedule from start.
Task B: Set constraint "Must Finish On" or "Finish No Later Than"
Task A: Link FS and constraint is "As Late As Possible"

This may produce a problem... if your durations run longer than desired, you
will see your final task "snaking backwards" which means the schedule is not
valid.

There is probably a better alternative.... Set deadline date. This way, if
your constraint is violated, a red indicator will appear in the indicators
column and you will also know what your schedule logic tells you to
reasonably expect.


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If this post was helpful, please consider rating it.

Jim
It''s software; it''s not allowed to win.

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

 

[Ian]

So, I am reading between the lines that there is no way to get Project to do
what I am asking and the only fix is to change my approach? Is that correct?

Thanks very much, Jim.
///Ian

 

[Jan De Messemaeker]

Hi,

I have problem here.
However I approach this, the result is what you want (both tasks have dates
within one day)
But mind you I always use FS links.
So link A to be FS, set B as must finish on monday, set Project as schedule
form finish date.
A now starts and ends on Friday.

So much about the product.
What Jim meant was you better not plan as late as possible because what
there is a headwind on even one task you are losing the battle for an on
time propject.
But you say you want this approach "to see when it has to be ready".
In that case my ADVICE (and please do not interpret that as something about
MS project. That can handle any approach!) is to schedule from start date
with FS links, Start/Finish now show the earliest dates; but insert the
columns Late Start and Late Finish, that is what you (also) want to know. No
need to schedule from Finish explicitly, Project always does that, you only
have to show the relevant data.
Hope this helps,



--
Jan De Messemaeker
Microsoft Project Most Valuable Professional
+32 495 300 620
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http://users.online.be/prom-ade/Calendar.pdf

 

[DavidC]

Hi,

Just to add a refinement I use. Often a finish-start relationship is needed
to identify the latest date an activity is needed to be completed by.

Example, a plan must be approved 60 days before testing starts. I then put
in a milestone being the deadline scheduled back 60 days from the start of
testing then set a dynamic link from the finish of the milestone to the
deadline field of the task that needs to be completed before that date. This
then allows the "As soon as possible" logic to operate, but places a deadline
for when it must be finished by that will change if the testing date moves.
Watching the Total slack (or free slack) enables me to warn of impending doom
if progress on the required documents is not being achieved.

I find this is a realtively common thing I need for construction and works
reasonably well.

 

[Steve House]

There are just so many things wrong with this approach it's hard to know
where to begin. First of all, how do you KNOW that the project will end on
a certain date? You may NEED the project to end on X date but that's
another thing altogether ... scheduling from finish date backwards implies
you are either clairvoyant and can see the future or have a time machine
that lets you go into the future and retroactively document what took place.
Planning backwards gives you the latest possible date you can start each
task and finish on time IF AND ONLY IF everything goes exactly according to
plan. But the one thing you can absolutely count on in any signifigant
project plan is that something is going to be late. Thus scheduling from
finish backwards, while interesting from an academic point of view, is a
virtual guarantee that your project WILL NOT finish on time.