Multiple Dependecies between the same tasks

[scott_hanebutt]

I have been doing a lot of reading on Project can came up with a hypothetical
scenario and would like to know how it should be handled.

Sopose someone is writing a book and someone else is editing it and that
editing it will take 1/2 as long as writing it does.

Obviously you can't start editing until you start writing making it a
start-to-start relationship. Just as obviously you can't finish editing
until you finish writing making it a finish-to-finish relationship.

It seams to me that neither one of these relationships can adequatly handle
this situation without the other.

With the start-to-start relationship the editing will finish before the
writing which does not work.

If the finish-to-finish is used this is not a problem but then the editing
is starting much later then it has to. If for some reason the editing takes
longer then expected, or the editor is forced to spend time on something then
editing will finish later then it had to.

Any thoughts?

Thanks,
Scott Hanebutt

 

[Jan De Messemaeker]

Hi Scott,

Yes.
The tasks have to be split in the sort of packages the writer will pass to
the editor.
Each writing package is linked FS to an editing package.
That's is how I hanldle such situations.
HTH

 

[scott_hanebutt]

Makes sense. I don't know why I didn't think of that.

Thanks,
Scott Hanebutt

 

[davegb]

Makes sense. I don't know why I didn't think of that.

Thanks,
Scott Hanebutt

That's why we keep Jan around. Every once it a while, he makes sense!

 

[Steve House [Project MVP]]

I see this one as a classic use of a lead time. The book can't be edited
until it has been written. That makes it a FS relationship. But we don't
have to write the entire book before we can begin editing the first
chapters. So we consult with the editor and he tells us he'll have enough
to get started with if he gets the manuscript after about 50% of it has been
done. That means editing can start when we're 50% of the writing duration
away from writing completion. The link is FS with a lag time of -50%
(negative lags are leads). OR if he says he can start when the first
chapter is done and there are 15 chapters, the link is FS with a lag of
perhaps -90%. Remember too that a link is permissive, defining the earliest
point where the successor is permitted to start. There's nothing that says
other factors might not enter the picture to make it start later, like the
editor being tied up with something else when the writer delivers the first
chapter(s) to him.

 

[Jan De Messemaeker]

Hi,

But when the second task is comparatively small negative lags don't solve
anything.
To me, negative lags are never any good since you will take the decision to
start based on something which is still unknown (the finish of the first
task).
Greetings,

 

[Steve House [Project MVP]]

Anything planned is always going to be an unknown until you do it. But we
can say with reasonable certainlty that *if* it will take the author 100
days to write the 10 chapter book, it will probably take him 10 days to
write the first chapter, thus the editor can expect to be able to start
editing the first chapter about X date and should plan his time accordingly.
True enough, we could go with SS with a positive lag or FS with a negative.
Which would work best in any given project is probably up for grabs.
--
Steve House [MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs