Problem with multi-SF predecessors
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Tomas:
Yes, youre right, we can fix the unreal slack this way... thanks.
mmm... I dont have any idea about equivalent solution in Primavera...
Nader:
That is a nice solution.
It solves your problem but not completely.
You need to complete your logic and have your total float correct.
You should add your b, c and d activities as FS succesors of your g activity.
The way it is now, if your g activity delays, your b, c and d activities are not affected.
I do not think this can be replicated in Primavera 5.0 since the equivalent activity type is WBS Summary which ignores relationships during scheduling.
Any thoughts by anyone on how to replicate this in Primavera?
Tomas Rivera
well, Ive found out the answer right now!
the key is using a summary. This sample shows the solution:
http://www.khorramirad.com/index.php?id=112
comment: I dont know how to paste images here, so Im linking to my own weblogs post about this. You can see the plans image there.
If I understood correctly it is not a problem of SF links but the problem of "OR" logic that is not supported by Primavera and MSP.
Dear Nadir
there is sugestion, try and i hope will work for your project and not affect your other links. Creat your mile stone / activities and FF realtion with negative lag how many duration you want to for example
activity
A----> fs xxx
B----> ss (10) YYY
C----> FS A
fs ddd
Now D new activity developing of data sheets for civil fdn or what so ever
D-----> FF (-duration as 30)
Surely this will solve your problem.
Good luck
Tahir
Thanks everybody; but using other relations would not be a solution for me.
Suppose we have 3 tasks, each having different predecessor(s) and a start date calculated by them. Now, we need to have something prepared before starting each of them (some kind of specifications, drawings, datasheets,…). This need is going to be a milestone, and the logic behind that, is that it can simply be prepared whenever we want (doesn’t need any special work to be done). So, I want to have a milestone, showing us when this “need” should be prepared.
My milestone should be dynamically linked to those 3 tasks, in a way that start before earliest of them.
It is possible to make milestone FS predecessor of those three tasks, and make milestone ALAP. This works in Primavera, because Primavera uses free slack for ALAP constraint, but MSP uses total slack and this solution would not work (thanks to Paul Harris for this comment).
I’m now looking for a solution in MSP.
Thanks again :)
-nader
I have had similar situations occur and I completely agree with Brennan. You will be much better off with FS or SS with lag.
Ive had clients that would freak out by going out of sequence on logic and when I would explain to them that the activities that would normally be worked on today could not be done due to inclement weather (for example) and I decided that the better use of manpower was to have them start the other activities until weather cleared up usually did nothing for me. At least 6 out of 10 times the client would say " Why didnt you schedule it like this in the first place and hire more workers for those tasks?"
I really hate it when they expect you to be a psychic too. lol
Nader,
That is really a big big problem
That is one reason i discourage to use that type of relationship.
As much as possible use FS.
Cheers,
Charlie
why not just use FS or SS with a lag?
SF means that C should start before A and B can finnish.
it might be easier to find a suitable solution if you tell us what the activities are.