Summary Bar Linking

[Paul]

I have inherited a plan where the former owner has on a few occasions
linked to the summary bar. Can someone please tell me the disadvantages of
linking to the summary bar. For example, is it true that linking to a
summary bar project will not show a critical path through the whole plan?
Are there any other reason why you should not link to summary bars?

Thanks for your help.

Paul

 

[Mike Glen]

Hi Paul,

Welcome to this Microsoft Project newsgroup

You might like to see FAQ Item: 48 - Summary Task Linking

FAQs, companion products and other useful Project information can be seen at
this web address: http://www.mvps.org/project/

Hope this helps - please let us know how you get on

Mike Glen
Project MVP

 

[davegb]

Wow! You just stepped into a hornet's nest. There are widely varying
opinions about linking summary lines in this forum. I'm in the
"strongly against it" group. The reasons some of us discourage it
include:

1. It's a major cause of "circular references", which are circular
loops of task dependencies, obviously impossible in the real world.

2. They hide the real CP.

3. They can cause problems with Resource Leveling.

4. They can cause problems with EVA.

Bottom line is, linked Summary lines misrepresent what's actually
happening in the project. Sooner or later, mostly depending on how
advanced your scheduling and tracking is, you'll get into trouble with
them. In my mind, they're just an easy way to avoid having to define
the real dependencies between tasks. Defining these dependencies is the
most important part of CPM scheduling. Bypassing defining them and
going on with a schedule is like not bothering to build a foundation
under your house.

Oh yes, I should add, IMHO!

Hope this helps in your world.

 

[Rod Gill]

If you are a novice scheduler, then keep things simple and don't link to
summary tasks.

Linking to summary tasks does still show the critical path.

I link to summary tasks but only when I need to link to a GROUP of tasks.
For example: If resources are working in one area and must finish all work
there before moving to the next area (maybe because it's in a different
building) then I would link the summary tasks for the first area to the
summary task of the next area. Why? because to make sure no task in the
second area started until all tasks in the previous area finished I would
need to add a link to each task and that is confusing and clutters the Gantt
Chart.
One Summary to Summary link is neat, accurate and reflects what's happening
in real life. If you are a novice then just link the last task in the first
area to the first task in the next area. However, if the last task in the
first area in fact finishes early and other tasks finish last, you have to
set constraints on the first task in the second area or start adding more
links. Got that?!!

 

[Paul]

I didn't realise that this was such a complicated subject.

Thank you all for your responses.

Paul

 

[davegb]

If you are a novice scheduler, then keep things simple and don't link to
summary tasks.

Linking to summary tasks does still show the critical path.

Rod,
You can look again and see that I didn't say that linking to Summary
lines doesn't show a CP. I said it hides the real one. If you have 20
tasks under the Summary, but the links go through the Summary, the
Summary will show as critical. But the actual tasks under the Summary
that are the longest path won't show critical unless you've linked them
properly. If you've linked them properly, that obviates the need to
link the Summary. If their durations are likely to change, a milestone
following the potential final ones takes care of that problem. Without
the high probability of getting circular references or messing up your
EVA.

There is a difference between showing "a Critical Path" and showing the
"correct Critical Path", don't you agree?