Why You Should NOT Assign Predecessors to Summary Tasks within MS Project
Date: Sunday, October 05 @ 07:59:45 EDT
Topic: PMConnection Articles

Here is One Reason Why You Should NOT Assign Predecessors to Summary Tasks within Microsoft Project:


I needed a schedule within Microsoft Project that I could quickly open and work with to provide a demonstration. I elected to open the “Wine Tasting Fundraiser” template found within Microsoft Project 2010. (Find hundreds of Microsoft Project schedule templates here)

As I started working with this file, I was extremely disappointed to find many best practices of working with Microsoft Project had not been followed. The individual who produced this schedule violated a number of items found in this article: “10 Signs You Don’t Really Know Microsoft Project“.

As I was in the process of fixing this schedule, I got stumped for just a moment. Here is what happened:

As I looked at the Gantt Chart portion of the Gantt Chart view, I was curious how a number of the tasks (6,12,13,17,22) were starting nearly a week later than the first task within the schedule.

I first thought that someone had hard-coded the Start date of these tasks. But upon investigation, all tasks were scheduled to start “As Soon As Possible”.

Then I thought, well maybe the Start date of the project is set to Friday 10/10/14 and task 1 has a constraint. I inspected the Project Start date only to find it is set to Monday 10/6/14.

Next I thought that somehow the person who developed this template modified the Gantt Chart portion of the Gantt Chart view and changed the default option on how the “Link” arrows are displayed. Turns out this was not the case either:

Right click on the Gantt Chart and select Layout. The Layout dialogue box will display:

Next, my eyes catch that there are no Predecessors for these tasks of question:

And then I see it. The culprit! I see the 3 that has been placed within the Predecessor column on the “Planning” Summary Task (#4). This is violation number 5 of the article referenced above.

I removed the 3 from the Summary Task and input that as the Predecessor on those tasks that appeared strange.

The Link arrows are now displayed connecting the Predecessor task to its Successors as it should.

If assigning a Predecessor to a Summary Task caused this much confusion while looking at 25 rows in a schedule, imagine how confusing it would be if there were a few hundred or a thousand rows!

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