schedule backward and forward?

[GTS]

Hi all,

I'm new to Project, so bear with me.

I am setting up a schedule for a future project, which will start within a
year.

The dilemma is that the project has a number of tasks that must be done at
the last minute (the project is a show). We have tasks at the beginning of
the endeavor and have anticipated lag time so that everything will ready for
the big scramble at the end just before the show. After that, there are
removal tasks that can be done at leisure.

The last minute tasks have dependencies and resources associated with them.
They are only associated with the tasks at the beginning in that all those
need to be done before the last-minute tasks start.

I know it's not recommended to try to schedule backward and forward in the
same project, but I don't know if there is a way to schedule this kind of
scenario without making it so complicated that we can't make changes as the
project progresses.

The "late as possible" constraint pushes the tasks to the end of the project
(makes sense). Is there a way to say "as late as possible but before this
other task"?

A co-worker suggested setting the tasks up with a start-to-finish constraint
with the predecessors moving backward from the deadline date. Is this a good
idea?

How would you approach it?

 

[Rod Gill]

I would avoid all constraints as much as possible. Once the project starts
there will inevitably be some tasks driven only by availability of premises,
people etc. Once known they need dates. Everything else should be driven by
links. Use the Finish-Start link as recommended!

--

Rod Gill
Microsoft MVP for Project

Author of the only book on Project VBA, see:
http://www.projectvbabook.com

 

[Jan De Messemaeker]

Hi,

What shall I say? Project ALWAYS, spontaneously, without asking, schedules
BOTH forward and backward. Early Strat, Late Start, Early Finish, Late
Finish... all there fo the taking.

About ALAP constraint: suppose tasks "Final Cleaning" and "Day 1 of the
show"
link Final Cleaning FinishToStart to Day1 of the show
Set Final Cleaning ALAP.

Insofar Day1of the Show has an immovable constraint (Must Start ON for
instance) that is what you ask for.
Hope this helps,

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

 

[GTS]

Rod--I'm with ya on avoiding constraints. I avoided all constraints in the
building of the schedule until now when I'm pretty sure of what will
transpire. Thanks for the advice

Jan--Brilliant! It worked.

Anyone--
Any ideas about how I can test it to make sure it doesn't flip out in 2 years?

 

[GTS]

OK. so it worked for the tasks attached to Day 1 of the show. But now I need
to set 2 more sets of tasks up to come as late as possible before the set of
tasks that comes as late as possible before Day 1 of the show.

These two last sets aren't pointing at the task with the immovable
constraint, so when I apply the ALAP to them, it shoots them out after the
show.

Am I making sense? How would you approach these?

Thanks again for all your help!

 

[Jan De Messemaeker]

Hi,
Honestly, there is no good way to do it in Project. It is a terribly weak
spot. ALAP indeed makes the task and its complete successor chain critical.
In other words, ALAP is NOT Just in Time.

The officially recommended way to simulate just in time is to use a backward
link from the start of the "true" succssor to the finish of the "true"
predecessor. Indeed, that positions the plan as Just in time BUT whenever
the "true" predecessor might be late it will noyt make the "true" successor
move: in fact you won't even get a warning.

Lousy but I'm afraid Project doesn't offer any better.


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

 

[GTS]

Thanks Jan,

Now I'm not feeling so stupid!

I'll work on it with that mindset and we'll see how it turns out.