ISERROR
ISERROR(value)
TRUE when working out a value failed on that row: a division by zero, ONLY on a set that doesn't hold exactly one row, the square root of a negative number. A blank isn't an error, so ISERROR of a blank value is FALSE.
Arguments
| Argument | What to give it |
|---|---|
| value | Any single value: usually a calculation that can fail on some rows. |
Examples
Formula=ISERROR([Duration] / [Remaining duration])
TRUE where the division fails: tasks with no remaining duration, such as milestones.
Formula=ISERROR(ONLY(Predecessors)[Finish date])
TRUE on tasks that don't have exactly one predecessor: none, or several.
Formula on WBS rows=COUNT(FILTER(Tasks, ISERROR(Tasks[Remaining duration] / Tasks[Duration])))
On a WBS row: how many tasks under the node would fail a share-remaining calculation, because their duration is zero.