Using predecessors in Summary tasks (flaw 6)

Hey People,

Let me start by thanking you for some of the great responses I got on my serries on incorrect way’s to use Microsoft Project stand alone version. Most people agreed on the flaws I noted in the series of blogs, and some had additions to the flaws.

I have picked a number of additional flaws, that I believe need to be discussed. Today I’ll post my thoughts on linking summary tasks. This flaw was suggested by Swagato Bandyopadhyay, thank you, I hope you like what I did with your suggestion.

This flaw is easily created in your schedule when you are building your list of activities and want to indent or outdent after you have set your predecessors. The line of thought is even an understandable one: “Phase Y can’t start after phase X is done”. However, it is not a phase that starts or finishes! The activities and milestones within the phases start or finish.

This is what it looks like in a schedule:

Thinking logically it isn’t phase 1 that is needed for phase 2. It’s the approved PID that is needed for the starting task.

In complex schedules it’s often posible for a phase to overlap another. With linked summary tasks this will not be possible, creating a false gap in your schedule. There is even chance that you run into a circular reference error with the following text:

You are trying to link a task to another task that has a series of task links back to the first task. You cannot do this because it would create a circular task relationship with other tasks.

Finding the links

Luckily there is an easy way to check for these links in Microsoft Project. Using the Gantt chart view and filtering this view to show just summary tasks, you can now view the predecessors, if there are any they should be deleted. Going back to the example this would be your view:

The summary tasks are all bold text, so finding a predecessor link will be extra easy.

That’s it for now, if you have any suggestions for posts please let me know.