Calculate Start Date for task dependencies

[Michael_Burnett]

Hello!

I am trying to figure out a formula that grabs a start date when a previous task ends. So in row 2 the Task Dependency is DEC:Project Setup. In row 1 you see the task is DEC: Project Setup with the task due date being 5/13/2022. I want to create a formula that takes this due date and puts it as the Task Start Date in row 2.
Thanks in advance for any help anyone can provide!

[wellwisher]

Hello Michael_Burnett

I do believe that this is possible with a bit of a workaround:

In short, the key is to get around the circular reference by taking a copy of the desired Start Date from the predecessor record and pasting it as raw, "unlinked" data in another column. This can be accomplished via automation.

The table below is a screenshot of how I accomplished this.

1) In the "Start Date" column I have a formula that will pull the date from the "State Date (Override)" column only if the "Start Date Copy" column is blank.

2) So how does the "Start Date Copy" column get populated? Well, I have an automation that is triggered when the "Start Date-From Nearest Blocker" column becomes populated. Once this occurs, that same date is copied into the "Start Date Copy" column, thus eliminating the circular reference.

3) But what is the "Start Date-From Nearest Blocker" column and how did it get populated? Well. First I created the "Nearest Blocker" field as a linked record, pulling in all the records from this same, exact table. Then I created the "Start date-From Nearest Blocker" field as a lookup, pulling the value of the Start Date from the record noted in the "Nearest Blocker" field. 

4) And wiz, bang, it all seems to work.

I pray this is helpful my friend.

[Helenelene]

Hi @wellwisher 

I am struggling with a similar problem and I'm not sure if you solution would also work in my case:

I am building a master Project Management Base for my colleagues. The goal is, for each new project copy it and just change the start date and all the other dates for each step would change accordingly (like cascading down). Also in case a certain task within a project took longer (eg. 5 instead of 2 days) the remaining due dates should move back as well.

I could only create a list, where I use the end date of one task as start date of the next date. but I still need to enter the dates manually for it to work. Thanks a lot in advance 🙂 

[wellwisher]

Hello Helenelene. After looking at the problem you're trying to solve, it is fundamentally the same as the problem that I was trying to solve as far as I can see. The fundamental air table issue in a case like this is that you get a circular reference when you are using data from a column that you are looking up from the same table. In cases like this the data must be copied to a column that has no dependency on the looked up column. So applying automation in the manner that I applied it will likely solve the issue. Does that help?