About Those Pesky Question Marks in the Duration Column

When working within a new project, have you ever noticed those question marks in the Duration column for every task that has the default duration of 1 day? If memory serves me correctly, Microsoft introduced a new feature called Estimated Durations in Microsoft Project 2000. In fact, I distinctly remember how very experienced users of the software complained about this new feature, and often asked me how to get rid of it!

By default, the Estimated Durations feature is enabled in every version of the software, which means that you will see a Duration value of “1 day?” for every new task you add to the schedule. This feature is intended for project managers who estimate Duration values rather than Work values in their projects.

Figure 1: Estimated Durations


If you are a project manager who does estimate Duration values in your project, the Estimated Duration feature will display a question mark on the Duration value for every task until you manually enter a Duration value. After you manually enter the Duration value for a task, the question mark symbol will disappear. This means that if a task has the default Duration value of 1 day, and you want the Duration for that task to be 1 day, you must still manually type the 1 day value into the Duration cell to make the question mark disappear. Notice in the following figure that I have manually typed a Duration value for each task in the PHASE I section of the schedule and that the question marks no longer appear for the PHASE I tasks as a consequence.

Figure 2: Duration estimates entered for Phase I tasks


If you are a project manager who estimates Duration values in your projects, the Estimated Duration feature can be very useful. Before finalizing the project schedule, you should visually scan the Duration column, looking for any task Duration value with a question mark. Manually type a Duration value for every remaining task until all the question marks are completely gone.

If you are a project manager who estimates Duration values in your projects, but you manage large projects with a thousand or more tasks, visually scanning the Duration column for question marks can be a cumbersome process. A better approach would be to use the built-in Tasks with Estimated Durations filter. To use this filter, click the View tab to display the View ribbon. In the Data section of the View ribbon, click the Filter pick list and select the Tasks with Estimated Durations filter. By applying this filter, you can quickly spot any residual tasks with an Estimated Duration. Manually type a Duration value for every remaining task until all the question marks are completely gone and then press the F3 function key to clear the filter.

Figure 3: Tasks with Estimated Durations filter


If you are a project manager who estimates Work values rather than Duration values for tasks in your project schedules, you will probably find the Estimated Durations feature of little value to you. For example, notice in the following figure that I assigned Mickey Cobb to the Design 2 task with a Units value of 100% and a Work estimate of 56 hours. After assigning her to the task, Microsoft Project calculated a Duration value of 7 days, but notice that the question mark still remains in the Duration field. The question marks only disappear when a Duration value is manually entered; they do not disappear when the Duration value is calculated.

Figure 4: Estimated Duration does not disappear


If you are a project manager who estimates Work values rather than Duration values for tasks in your project schedules, you will probably want to disable the Estimated Durations feature in all of your projects. To disable this feature, complete the following steps:

  1. Open a project.
  2. Click the File tab and then click the Options button in the Backstage.
  3. In the Project Options dialog, click the Schedule tab.
  4. In the Scheduling options for this project section of the dialog, deselect the Show that scheduled tasks have estimated durations checkbox.
  5. In the Scheduling options for this project section of the dialog, deselect the New scheduled tasks have estimated durations checkbox as well.
  6. Click the OK button.

Figure 5: Disable the Estimated Durations feature


After completing the preceding steps, the question marks in the Duration column will disappear for every task in the schedule. You will need to repeat the preceding steps for every project schedule you manage. In addition, I recommend you complete the preceding steps for every schedule template you use as well.


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Written by Dale Howard
Dale Howard is currently a Senior PPM Consultant with Arch Systems, Inc. His hair and beard have turned white because of using Microsoft's project management tools for more than 20 years. Dale started his career using Microsoft Project 4.0 for Windows 95 and began using Microsoft's PPM tools when they introduced Project Central in 2000. Dale is the co-author of 23 books in Microsoft Project, Project Server, and Project Online. He is currently one 0f 26 Microsoft Project MVPs in the entire world and one of only 4 Project MVPs in the United states.
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  1. Hi all, I would like to point out that ‘estimated duration’ means ‘this number is arbitrarily entered (guesstimated) by Microsoft Project engineers but may not be true at all’ and is blatant example of ‘Microsoft Speak’, the Orwellian language developed by Microsoft Engineers. The Microsoft Speak term ‘estimated durations’ suggests to the users of the interface that:
    1) Microsoft Project is ABLE TO estimate, which is NOT TRUE last time I checked, only project contributors are able to estimate
    2) Microsoft Project is often correct in its ‘estimated durations’, which is partially true. It is not true for the default durations of ‘1 day’. It is fairly true for the durations that Microsoft Project calculates based on the formula D * U = W, another source of question marks.
    Instead of calling the question-mark-feature ‘estimated durations’, the engineers should have called it ‘mark numbers arbitrarily entered by Microsoft Project itself with a question mark’.

  2. As usually a great article and nugget of information that makes my life easier.

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    @Eric Uyttewaal, I don’t agree. I use the “? mark” all the time to indicate that I don’t know how long a task will take, and during a collaboration, others can help me determine durations by scanning that column for the marks. I also don’t get the vitriol towards MS Engineers 🙂

  4. Good article on a frequent question of MS Project users. I don’t use this feature in schedule planning, but might start applying it where input data is limited or questionable. On Eric’s comment above, I think the formula stated is correct, but to solve for duration you’d want D = W/U. Also, this formula is changed when you specify a task as Fixed Duration, in that case Work and Units would be adjusted depending on what you change.

  5. @Jigs, I guess what you describe as ‘vitriol’ comes from 26 years of Microsoft ignoring my suggestions (even the really-good ones and cheap-to-implement ones).
    The language for this option could be adjusted easily were it not for the fact that it also requires a field name change and Microsoft always hates doing this because it creates backward compatibility problems. This is why we have ended up with a product that has many dead-wood branches in it that:
    A) Should be cut out or, better yet,
    B) Microsoft should consider rebuilding Microsoft Project from the ground up again and doing it properly the second time around (which other companies like Tesla actually do), or best yet,
    C) The cloud version (Project Online), I think, provides the technological infrastructure to address some of these backward compatibility issues programmatically. However, either Microsoft has not thought of this or has not figured this out yet, since I have not seen them cutting out dead wood yet.
    Sorry for more language that may be interpreted as ‘vitriol’ but is really meant ‘for the greater good’ for all of us. I surely will not earn merit points with Microsoft for my ‘for the greater good’ remarks or be welcomed as an MVP again … I have just stopped caring about what Microsoft thinks of me …

  6. @Chris R: you presented an easier to understand formula indeed, that I should have used.
    On your other remark “”this formula is changed”, I do not agree because the formula stays the same … always. The fact is that users who do not know how to work a 3-variable formula or those who use the field ‘Effort Driven’ (another example of almost-dead-wood) get into trouble. The best way to use a 3-variable formula is: 1) Determine which value / variable you want to change 2) Protect one of the other two variables by setting the task-related field ‘Type’ to the corresponding type (Fixed Duration, Fixed Work or Fixed Units), and turn ‘Effort-Driven always to ‘No’ 3) Make the change you wanted to make in the first step.
    Hope this helps (for the-greater-good),

  7. @Dale, great article, my friend; keep them coming!

  8. Good point Eric. And thanks Dale for the article. I enjoy both the articles and comments.

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