Double Dependencies - Two SF Dependencies

merritt.delia

I have four tasks in this example. Task 4 is the schedule driver, all dates should flow backwards from task 4. For Task 2 and Task 3 I use 9SF as the predecessor relationship. For Task 1, I would like it to be driven to finish at the start of whichever of Task 2 or 3 needs to start first. In this case I would expect that Task 1 defaults to finish at the start of Task 2 as that would drive Task 1 to happen sooner. Could someone give me a hand with this one?

Thanks,

Merritt

Brett Wyrick

Hey Merritt, this had my head spinning for a second, but I think I get what you're going for.

Correct me if I'm wrong:

According to your screenshot, you expect that Task 1 will take place the day prior to the earliest Start Date from Task 2 and Task 3. That date would be 11/14, which is the day prior to the Start date of Task 2. Did I get that right?

According to how Smartsheet's native "Predecessor" column works, if a row is dependent on 2+ other rows for a Start-to-Finish relationship, the row's Start date will default to the latest start Date. That's why you're getting 11/19. The Start date of Task 3 is 11/20, so a day prior to that is 11/19.

From Smartsheet's documentation on Dependencies & Predecessors (formatting mine):

...on Finish-to-Start relationships, Smartsheet will schedule the dependent's start date after the LATEST occurring end date of all predecessors.

So to rephrase this for your use case, it's the opposite:

...on Start-to-Finish relationships, Smartsheet will schedule the dependent's start date after the LATEST occurring Start date of all predecessors.

----

So... how do you fix it?

If it were me, I'd put Task 2 and Task 3 under a parent task (shortcut: Ctrl key + "]" key), then make Task 1 dependent on it. This effectively groups Task 2 and Task 3 together as one "row", which you can then make Task 1 dependent on.

My parent task is named "Task Group" and highlighted in yellow above.

Task 1's Predecessor column is now "5SF" rather than the "6SF, 7SF" you had prior.

Let me know how this works for you, Merritt!

merritt.delia

Thank you Brett, I think this grouping fix will work nicely!

Brett Wyrick

Hey Merritt, this had my head spinning for a second, but I think I get what you're going for.

Correct me if I'm wrong:

According to your screenshot, you expect that Task 1 will take place the day prior to the earliest Start Date from Task 2 and Task 3. That date would be 11/14, which is the day prior to the Start date of Task 2. Did I get that right?

According to how Smartsheet's native "Predecessor" column works, if a row is dependent on 2+ other rows for a Start-to-Finish relationship, the row's Start date will default to the latest start Date. That's why you're getting 11/19. The Start date of Task 3 is 11/20, so a day prior to that is 11/19.

From Smartsheet's documentation on Dependencies & Predecessors (formatting mine):

...on Finish-to-Start relationships, Smartsheet will schedule the dependent's start date after the LATEST occurring end date of all predecessors.

So to rephrase this for your use case, it's the opposite:

...on Start-to-Finish relationships, Smartsheet will schedule the dependent's start date after the LATEST occurring Start date of all predecessors.

----

So... how do you fix it?

If it were me, I'd put Task 2 and Task 3 under a parent task (shortcut: Ctrl key + "]" key), then make Task 1 dependent on it. This effectively groups Task 2 and Task 3 together as one "row", which you can then make Task 1 dependent on.

My parent task is named "Task Group" and highlighted in yellow above.

Task 1's Predecessor column is now "5SF" rather than the "6SF, 7SF" you had prior.

Let me know how this works for you, Merritt!

merritt.delia

Thank you Brett, I think this grouping fix will work nicely!

Brett Wyrick

@merritt.delia Glad to help, glad it worked! Have a great weekend and let me know if you run into anything else!

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