my should-be-better experience with predecessors and lags

edited 02/11/21 in Smartsheet Basics


I have these tasks:

dates are correct and must not be changed.

Case 1: predecessors at leaf task level

Now I want to add predecessors. Task 119 can only start when task 115 is completed.

so I add 115 but Smartsheet has automatically changed task 119 dates:

This is wrong. it should not change 119's Start Date automatically.

Smartsheet should:

  • Stop assuming that FS means the next task (119) has to start the next business day! (it can be the same day or 1 month later, think of holidays)
  • OR Automatically add the Lag to match my dates.
  • Warn me before changing task 119 Start Date (you do warn me if I change the date and Smartsheet then remove the predecessor task number)
  • OR add a predecessor Type called FS "neutral" where the date is not changed (of course task 119 could not start before task 115)

At the moment, my only choice was to set the Lag manually. But that's not a great experience neither: I have to calculate the number of working days between the 2 dates so you end up best-guessing the Lag until task 119 Start Date is back to 01.03.21. (or rely on Excel where you manually enter the 2 dates and a formula calculates the Lag in working days...).

Case 2: predecessors at parent task level

This is when I want to have a more "aggregated" approach to dependencies.


Group task 118 can only be completed when group task 114 is completed.

I set task 114 as predecessor of task 118 and all dates (Start, close) of all sub tasks are ruined:

There is nothing to do to save this.

Lag is not functional, any value I put is just ignored.

Case 3: multiple dependent tasks on the same day

I wish duration could also be done in hours (or at least in fraction of days e.g. 0.25 ; 0.5). This would allow 2 tasks (one being the predecessor of the other) to be planned on the same day and not over 2 business days. At least there is a workaround that works here: force a duration of 0.

Case 4: undo changes not working after auto-save

This can be anxiety inducing:

when adjusting the Lag or the type of predecessors, many dates (could be hundreds) are changed across the plan. Many times, I just want to rollback my changes, sometimes rollback multiples changes.

Easy: I just click the undo button as many times as I need and all the dates are back to where they were. but if the "auto-save" kicks in, then the undo button is disabled and I can forget what I've done before. This auto save is so scary that I have to make screenshots of my plan before I endeavour several big changes. This allows me to have a reference point if case I have to manually rollback my plan, which could take a significant amount of time.

Would it be reasonable to ask for an improvement that smartsheet should warn + offer an option to auto-calculate the Lag if the current dates need to be changed? In project management, the dates are often set in stone and therefore should not be changed automatically. The Lag should.

Maybe even introduce the concept of "locking" the date, which would then tell Smartsheet to adjust the lag automatically. so user have 2 options:

  • I lock the task dates and adding predecessors should auto-calculate the lag
  • I don't lock these dates and adding predecessors can update the date (and therefore not add any lag, which is the current behaviour)


  • Genevieve P.
    Genevieve P. Employee Admin

    Hello @Largo

    I'll do my best to address each section in order below, but if I've misunderstood or missed anything please let me know!

    Case 1: predecessors at leaf task level

    You are correct: lag time must be manually specified when you add the predecessor row number, otherwise the row will automatically adjust the dates to have this new task start immediately after the previous row. See the very bottom paragraph in this Help Article: Enable Dependencies and Use Predecessors

    Please provide the feedback you've outlined here to the Product Team by using this form.

    Case 2: predecessors at parent task level

    This is due to the Parent Rollup functionality. Parent rows reflect the data in the Child rows (ex. the Start Date is the the earliest Start Date from their children and their End Date reflects the latest End Date from their children). I personally think of Parent Rows more as a header to the tasks below versus a task itself.

    To have one group start immediately after a previous group, you'll want to put the predecessor on the first task in the group, basing it off the end task of the previous group. Then have each of your following tasks based off of this first child (or based off of the subsequent children, depending on your set-up).

    Case 3: multiple dependent tasks on the same day

    This is possible! Duration can be partial working days, hours, minutes, etc. There's a chart in this Help Article that shows how to format this: Work with Duration and Predecessors

    Case 4: undo changes not working after auto-save

    You may want to adjust your auto-save settings (Account > Personal Settings > Settings). You can set this to only auto-save after 10 minutes of inactivity, if this helps.

    Keep in mind that you can always check the Cell History of your cells to review previous information. (Right Click on any cell and choose "Cell History"). Depending on your plan, you may have access to the Activity Log of you sheet which could help track changes, as well. (See: View Changes Made to Smartsheet Items.)

    I will also note that at Engage 2020 it was announced that our Product team is working on releasing a Baseline feature this year (see this Youtube video of the Keynote).You may want to subscribe to the Release Notes page so you can be notified when this is released.

    In the meantime, please do fill out the Feedback form for our Product Team, as they really appreciate hearing about each use-case.