Manual vs. Auto-Scheduling in Microsoft Project

Many of our users ask us about the two different types of scheduling modes available in Microsoft Project; Manual and Automatic, and what will work best for them.

Not surprisingly, this topic has loads of information on the internet available and I’ve included some helpful links to very useful articles or discussions below to help.  However, the goal here is to ensure you know how these scheduling modes work, and we’ll cover more about how to choose between them in a follow-up post.


Manually Scheduled Task – A task that you can set up to not change until you tell it to change.

Automatically Scheduled Task – A task that will include system-generated values when it is created.  The task data may then be modified by the system, as dictated by Microsoft Project settings, when called upon to do so.

Notable Settings:

Your default settings for how tasks will be scheduled can be accessed by going to File -> Options -> Schedule.  In the below example my tasks are set to be Manually Scheduled as I insert them into my project file.

Scheduling SettingsIf you want them to be Automatically Scheduled, instead, simply hit the dropdown (blue arrow) and select that option.  I’ve also noted a setting (black arrow) that will, if checked, allow your Manual tasks to move if other tasks that are linked to them move (predecessor relationships).  If you don’t ever want your Manual tasks to move until you move them, simply leave this setting unchecked.

Another way to change the default task mode is the click the button at the bottom left of your Project file and select the mode you want to use, per the below image.Changing default task mode

If you want to see each task mode in one of your views, simply insert the Task Mode column and you will see the icons for each task/milestone.Task Modes

What You Need to Know About How Each Mode Works:


  1. When you enter a task in Manual mode the Duration, Start, and Finish columns will be blank.  Once you populate two of these fields, the third value will be filled in for you.
  2. Blanks or text values are acceptable in Duration, Start, or Finish columns in Manual mode.  However, if you add a text value and then switch to Automatic mode Project will only do its best to translate to a date or numeric value, which may cause you to re-key certain fields.
  3. Manual tasks cannot be effort-driven.  The duration of a Manual task will not change as more resources are assigned or removed from it.
  4. Constraints will be ignored in Manual mode.
  5. Project and Resource calendars will be ignored in Manual mode.


There is a lot to learn about Manual mode, however, I’ve attempted to boil down the basics below:

  1. Automatically scheduled tasks are set up to have Start, Finish, and Duration filled in for you, based on your default settings (per Scheduling tab in Options above).
  2. Tasks will be adjusted in your plan as data changes for a variety of reasons.  Things that may cause movement in your plan are:
    1. If a task is linked to another task, moving it or changing its duration may move the task it is linked to…this could have a domino like effect to other tasks in your plan if they are all linked together.
    2. Resourcing – if you are using resources in your plan you may see movement as resource data changes (units/work/allocation).
    3. Constraints – if you’ve accidentally set up certain tasks to have constraints you may end up not seeing movement in your plan where you expect it to occur, or vice versa.
    4. Links, lead time, and lag time – How you’ve set up your links will also impact whether or not things will be modified (and how), as change occurs to your data.
    5. Calendar changes (Base, Project, Resource, Task) – if you happen to change the settings in any of your calendars then it may impact a schedule you’ve already created.
    6. A mix of Manual and Automatic tasks may also leave you puzzled as to why things are moving or not moving in your plan as a result of updates to certain data.

We’ll follow up with a post that will discuss how to decide which modes to utilize in the near future.  But hopefully this information will arm you with a basic understanding of Manual vs. Automatic scheduling.  Here is some additional advance reading that may help if you need to dig deeper immediately:–Auto-Dates

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About Jay

Jay carries with him fourteen years of project management experience within the cable, telecom, construction, software development, and energy industries. The spectrum of projects and programs that Jay has managed throughout his career is broad and deep, enabling him to help clients implement OnePager software in a multitude of applications.

5 thoughts on “Manual vs. Auto-Scheduling in Microsoft Project

  1. Have you seen circumstances were Constraints were created even with Manual Mode on? I’m currently looking into why this is happening when populating MSP programatically.

    • Hi Bryan, thanks for the comment! We have not personally witnessed any instances where Project is creating a constraint in Manual mode, where it shouldn’t be there, no. We’d love to hear what you figure out!

  2. Hi Jay,

    any way to easily visualize tasks which have Manual Scheduling ? Was trying to add a column with such indicator but didnt find any.


    • Yes that’s right. The Task Mode column from Project isn’t something OnePager is passed. That said, you could create a formula in a Text column that could then be used to pass that value to OnePager. If you’re using Text1, for example, the Formula might be IIf([Task Mode]=True,”Manual”,”Auto”). Would that meet your needs?

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