Reverse (backward) schedule - workaround help

Platform discussions
1

Good day! Been a while since I had the ability to work in this platform, glad to be back!

I wanted to reach out here to, hopefully, get some ideas or assistance on what I am trying to accomplish. I’ll try not to be too long winded.

I have built and automated a Project Management set of boards. The high level ‘Projects’ and the low-level ‘Tasks’. Each of the tasks has a set of 13 sub-tasks that make up the project, each with their own durations. I have everything flowing the way I would like, for the most part, however, what makes the most sense for us to be to have a reverse (backward) type of schedule, which doesn’t appear to be a thing…yet.

Sub-task 10 of the 13 is our installation task. Everything proceeding this, and the three after, need to be scheduled according to their own durations. For example, the task before it is a milestone invoice that is sent out to the customer. I have the duration set for that one at 60 days so I would like the start date to be that amount of days prior to the installation date. The process continues all the way back to the project ‘start’ date.

For transparency, I have played around with start/end dates but right now the timeline column (of the sub-tasks) is linked to the duration and dependencies columns.

In a perfect world, the installation date would be provided at the form submission and flow down to the sub-tasks to help drive the rest of the dates…and, hopefully, this can all be accomplished through automations/formulas, etc so that the only thing I have to manually set is the dependencies for each new project.

Okay, I apologize, it did get a bit long winded!

2

Hi @carlhaase1 Welcome back to the best work platform :rofl: :star_struck: :dizzy: … we love monday…

I have set up backwards planning before so it is possible to do based on generic set back / lag times etc But this was only on items not sub items!

I see this as a suggested workaround to review/try…

Basic approach:

  1. Treat the install sub‑task as the “finish”

    • Have a Date/Timeline on Sub‑task 10 = “Install date” (filled from the form or the parent item).

  2. Use formula columns on each sub‑task

    • For the milestone 60 days before install, add a formula like:
      Install Date - 60 days

    • Repeat for each sub‑task: Install Date - X days (or +X for tasks after install).

  3. Optional: mirror dates into Timeline

    • Either:

      • Leave these as Formula dates (for reference only), or

      • Use an automation + integration tool (Make/Zapier) to copy the formula result into a real Date/Timeline column so dependencies can still work.

  4. Form-driven install date

    • On the Projects board form, collect “Installation date”.

    • Push this into the sub‑items (via automations or a subitems template + “set date to match parent”).

3

Thank you for the reply. I’ve been trying to work on an option that would use a formula based on having the ‘installation date’ mirrored into the sub-tasks from it’s parent item but that’s been a real challenge, in itself. When I try and mirror from the parent to sub nothing happens. It should be mirroring the parent item but the creation doesn’t give me the option of ‘parent’.

If that makes sense!