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Back to Basics: Understanding summary tasks and subtasks

  • Article

When you sit down to think through a project plan, it often makes sense to group the project into several sections. For example, let's say I'm planning a software development project. First, I need to identify the scope for the project, and then write functional specifications documents that detail how the software application should work upon completion. After the specs are written, then the development team gets to work coding the application and handing off builds to the test team. The test team sends the bugs back to the development team for fixing, and eventually a finished product is ready to head out the door to customers. If I take a step back and look at this process, I can identify three distinct phases in my initial description of the work: Planning, Development, and Release. I can represent these phases in my Microsoft Office Project plan using summary tasks and subtasks.

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Looking at this example, the summary tasks are "Planning," "Development," and "Release," and the subtasks are the tasks that are indented below each of the summary tasks.

How are summary task dates and durations calculated?

Subtasks determine the start and finish dates for each summary task, as well as the summary task's duration. For this section, let's look closely at the first summary task in the example above, and its subtasks.

Task Name

Duration

Start

Finish
Planning 40 days

Thu 6/26/08

Wed 8/20/08
     Identify Scope 10 days

Thu 6/26/08

Wed 7/9/08
     Write functional specificatin 30 days

Thu 7/10/08

Wed 8/20/08

Duration. The duration of a summary task is the total duration of its subtasks. Using the example above, we can see that the duration of the "Planning" summary task is 40 days, which is the total duration of the two subtasks (10 days + 30 days).

Start date. A summary task gets its start date from the earliest start date among its subtasks. Using the example above, we can see that the "Planning" summary task takes its start date, 6/26/08, from the "Identify scope" subtask.

Finish date. The finish date for a summary task is the latest finish date among the subtasks. So, in this example, the "Planning" summary task takes its finish date, 8/20/08, from the "Write functional specifications" subtask.

What about resource assignments?

In a typical project, resources are assigned to subtasks, not summary tasks. However, there may be some situations where assigning a resource to a summary task is appropriate. If you decide to assign a resource to a summary task, there are a couple of things to keep in mind.

First, watch out for accidental overallocation. If you assign a resource to a summary task, don't also assign that resource to the subtasks, or the resource may appear overallocated. When dealing with resource allocations, Project treats summary tasks the same as subtasks, so if a resource is 75% allocated to a summary task, and 75% allocated to one of that summary task's subtasks, as well, the resource will appear to be 150% allocated. In actuality, the resource still has 25% availability, but it isn't represented correctly in Project because the resource is assigned to the same task twice.

Also, if a resource is assigned to a summary task, and that resource's time spent on the subtasks stays the same regardless of how the total duration of the subtasks changes, then that resource should be assigned to the individual subtasks, rather than assigned to the summary task. That is, let's say we have a resource, Ana Pavicic, assigned to the "Planning" summary task from our earlier example. Ana is a contract employee, and is required to log exactly 40 days on the subtasks associated with the "Planning" summary task. Currently, that's just fine, because the two subtasks add up to exactly 40 days. However, let's say the "Identify scope" task ends up taking 15 days instead of 10. The "Planning" summary task's duration increases to 45 days. Ana's assignment to the summary task now exceeds her required 40 day contract. Instead, it is better to assign Ana directly to the two subtasks, so that you can easily maintain control of her exact assignments.

Additionally, you should refrain from assigning resources to summary tasks if you do task status updates through Project Web Access.  Since summary task dates are driven by their corresponding subtasks, this can cause issues if the resource enters actuals outside of these dates.

Where can I learn more about summary tasks and subtasks?

The following resources can help you learn more about using summary tasks and subtasks in your project:

· Goal: Define phases and tasks

· Outline tasks into subtasks and summary tasks

· Display outlined subtasks and summary tasks

· Assign a resource to a task

· Create and link tasks with Project 2007

Comments

  • Anonymous
    July 17, 2008
    i want to assign the Tasks to my Team members, then my team members have to view their Tasks by clicking the "My Tasks" from project web access. Any demonstration to achieve this...

  • Anonymous
    February 26, 2009
    I have observed in one project that the summary task dates are not re-calculated based on the sub-task dates. The automatic calculation is on in the tools -> options. Any direction on this topic... -Nishant

  • Anonymous
    March 05, 2009
    If your calculation mode is set to Automatic, I'm not sure what is going on. Try hitting F9 to force Project to re-calculate everything. If this doesn't work, please add more details about this issue. Thanks.

  • Anonymous
    March 23, 2009
    I'm trying to figure out how to make the summary tasks and subtasks show in PWA.  I set up summary/subtasks in Project Pro 2007, but when I publish, the end user sees everything left justified...

  • Anonymous
    March 23, 2009
    I'm trying to figure out how to make the summary tasks and subtasks show in PWA.  I set up summary/subtasks in Project Pro 2007, but when I publish, the end user sees everything left justified...

  • Anonymous
    March 23, 2009
    I'm trying to figure out how to make the summary tasks and subtasks show in PWA.  I set up summary/subtasks in Project Pro 2007, but when I publish, the end user sees everything left justified...

  • Anonymous
    March 31, 2009
    The comment has been removed

  • Anonymous
    March 31, 2009
    Andy/Trevor - It sounds like you are referring to how summary tasks aren't showing up in My Tasks. This issue was somewhat fixed with the Project 2007 Infrastructure Update (more info: http://support.microsoft.com/kb/953751 ). With that update, when you select a task in My Tasks, you can see the task path (ie. the names of it's summary tasks). If this isn't the problem you are asking about, please provide additional details. Thanks.

  • Anonymous
    July 27, 2010
    How do I prevent my managers or resources from changing the finish date if they are behind schedule?  Is there a way I can restrict their ability to make this alteration?

  • Anonymous
    April 14, 2011
    what do i do if my summary task is NOT the total of all of my sub task combined duration?