TotalFloat for Non-Critical Path(s)

breso
breso ✭✭✭
edited 09/13/22 in Formulas and Functions

Hello, I reproduced a TotalFloat error from a larger project using a simpler template sheet. It occurs whenever there are multiple predecessors for a task in a downstream path. I took some screenshots to show what I am describing. Is this user error or some background calculation with the formula?

Formula (Column: Total Float): 

=IF([% Complete]@row = 1, 0, IF(COUNT(CHILDREN()) > 0, MIN(CHILDREN()), TOTALFLOAT([Task Name]@row)))

  • Screenshot 1: TotalFloat is 6 days for non-critical tasks (2A.1 to 2A.3) and 0 days for critical tasks (3.2). This seems to be functioning great!
  • Screenshot 2: Task 3.2 was moved off the critical path. TotalFloat is 0 days for non-critical tasks (2A.1 to 2A.3) and 3 days for the non-critical task (3.2). This is not correctly calculating 2A.1 to 2A.3 but is working great for Task 3.2.
  • Screenshot 3: Task 2A.3 added as a predecessor to Task 3.2. TotalFloat is 0 days for non-critical tasks (2A.1 to 2A.3).
  • Screenshot 4: Task 2A.3 added as a predecessor to Task 3.2 and Task 3.2 was moved off the critical path. TotalFloat is 0 days for non-critical tasks (2A.1 to 2A.3) and 3 days for the non-critical task (3.2)


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Answers

  • Julio S.
    Julio S. Moderator

    Hi @breso,

    In doing some testing, I was able to reproduce what you report. As you report, the calculations in your client's formula seem to work fine except for the tasks that are removed from the critical path. This seems to align with the expected TOTALFLOAT Function behavior where the project finish date seems to be redefined to the parent rollup instead of the final project date as the tasks are no longer part of the critical path.

    If you'd like to request a formula that also takes into account the total project final date for tasks that aren't part of the critical path, when you have a moment, please let our Product team know about your feedback by filling in this form, here. Thank you!

    Cheers!

    Julio

  • breso
    breso ✭✭✭

    Hi @Julio S.,

    I appreciate the feedback and have submitted to the form you linked to the product team!

    It was not clear to me that totalfloat would adjust depending on the parent rollup. I struggle to understand why the formula can return 3 days for Task 3.2 and at the same time 0 days for all of the Phase 2 tasks when neither are on the critical path.

    Total Slack is defined in this Smartsheet Guidance (Slack Time in Project Management | Smartsheet) as, “Total slack is the amount of time [days] a task can be delayed without impacting the delivery of the project.” So, it seems the formula still needs some work. These are base capabilities in MS Projects and Asana so it's difficult to use SmartSheet for project management when it still struggles with these core capabilities.

    It would also be great to have a free slack (free float) function.

  • Julio S.
    Julio S. Moderator

    Hi @breso,

    Sorry for the late comeback. I've been reviewing the environment and formulas and it seems that using more than one predecessor in each tasks is affecting the way the Critical Path is considered by the formula.

    For task 3.3 specifically, it seems like using the same predecessor as task 3.2 is also connecting both tasks and since this 3.3 is still part of the critical path while 2.2 isn't, it just considers Task 3.3 end date (10/20/22) and then calculates 3 days from 10/17/22 and 0 from 10/20/22. If you adjust the duration on either task you'll see the total float to recalculate accordingly on task 3.2.

    Again, for any additional requests that you may have regarding this function, I'd suggest raising the Form above to let our Product team know.

    Cheers!

    Julio

  • Hi,

    Has there been any update on resolving this problem? Or any suggested workaround? I would like to use total float for some advanced analysis via Smartsheet API, but with the formula giving errors like these it is not possible.

    Defining activities to have only single predecessor is not acceptable for me.

    Thank you,

    Tomasz

  • Hey,

    Any updates on this issue?

    Thanks!

    Sofia

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