Task Completion Reference in Project Report

[KatelynnKe2]

Hello! I am working on a project to increase visibility to project deliverables. I am looking to reference tasks completion dates in relation to a project using a project report. I have several deliverable tasks I want to be reported on a single project report.

Project Report
Reference Child Task: Task Completed
Reference Custom Calculated Field: DE:CalculatedDue
Desired Custom Column Output: Actual Completion Date of a task and the number from the custom calculated field in parenthesis IE: 3/24/25 (-4)

Formula:
displayname=Custom Column
listmethod=nested(tasks).lists(nested(children).lists)
shortview=true
valueexpression=IF({name}="Task Completed",IF(ISBLANK({actualCompletionDate}),"Subtask Found, No Completion",CONCAT(DATE({actualCompletionDate})," (",{DE:CalculatedDue}," days)")),"")
valueformat=HTML

Its outputting a blank field and I have tried multiple different approaches with no success. Interested in any ways to accomplish this. 

[Sven-iX · Accepted solution]

Hi @KatelynnKe2 

I recommend against iterating over a project's tasks collection in a report because the calculation is resource intensive (it for every row you're going through a list of dozens of tasks) .

When you're iterating over tasks you get ALL tasks, so iterating over a children would give you duplicates - and it's not supported. 

Instead, consider a TASK report where you filter to the relevant tasks, and sort by projectID group by project. Or consider using a milestone report.