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Logic MS Project

7 replies [Last post]
Thu, 2010-01-28 20:28
Jay S
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Why can’t SS & FF logic be used in MS Project?

What is the error in the programming ?
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Replies

Fri, 2010-01-29 07:44
#1
Vladimir Liberzon
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Hi Bo,
you are right, in your example it will work.

It will not work with the start milestone preceeding A, but will work with start milesone succeding A start.

I understood your proposal as the link to Finish milestone of activity B. In this case this milestone may be delayed without delaying B.

Thank you and Best Regards,
Vladimir
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Fri, 2010-01-29 07:03
#2
Bo Johnsen
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Hi Vladimir,

I’m not sure I understand you correctly.

Take your example: Let A in my example be "Preparation of Trench" and B be "Laying down Pipes". The finish-milestone C is then "Completion of Preparation of Trench".

"Laying down Pipes" (B) can start SS+x days after "Preparation of Trench" (A) has started, but "Laying down Pipes" (B) can’t complete before FF+y days after the finish-milestone "Completion of Preparation of Trench" (C). If finish of A gets delayed, the milestone C will get delayed and thereby also the finish of B.

I think we mean the same, however, please clarify about the resources being limited if I’ve misunderstood something.

Best regards,

Bo
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Fri, 2010-01-29 06:40
#3
Vladimir Liberzon
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Hi Bo,
it will not work correctly when resources are limited.
Activity may be finished but finish milestone delayed if preceding activity finished later.
Such links are typical for linear projects.
You can start laying down pipes when the certain length of the trench is ready, you can not finish laying pipes until the whole trench is ready.
Best Regards,
Vladimir
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Fri, 2010-01-29 04:50
#4
Bo Johnsen
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Plan Plan,

If you really want to use SS and FF between the same two tasks, you can do it in MS Project, but it will "cost" you an additional milestone everytime you want to do it.

Say task A and B. Introduce finish-milestone C being FS’ed (0 lag) to A. Let B be SS+x lag to A and also FF+y lag to C.

You can also so it the other way around, i.e. with a start-milestone and then just swap the links.

Regards,

Bo
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Fri, 2010-01-29 04:25
#5
Trevor Rabey
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Vladimir, wow, I am so surprised that you do not agree. I will change my opinion accordingly straight away.
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Fri, 2010-01-29 03:33
#6
Vladimir Liberzon
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Hi Trevor,
I don’t agree that both SS and FF links between two tasks is never needed. In most cases you shall use them both.
Best Regards,
Vladimir
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Thu, 2010-01-28 20:42
#7
Trevor Rabey
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Not sure why you ask. They can. They can’t both be used between the same tasks at the same time, but such a thing is never needed.
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