I'd like to understand better the restrictions applied to IIF (immediate Ifs) on MS Project 2016, such as:
- how many nested iifs are allowed
- how many characters are accepted in a formula
- how many characters are allowed in a visible on a custom field
1a. In MSP2016 custom field formulas, the maximum number of IIf functions to be nested is 14. (Same for the switch function - 14 conditions is the max.) Adding an extra level/condition causes a syntax error in the formula.
1b. There is no practical limit on the length of a formula. I've tested formula lengths over 1000 characters without problems (though I've not used them).
1c. Regardless of how they are populated (formula, lookup, or manually), custom text fields may hold no more than 255 characters. A longer string that is pasted into a custom text field will be automatically truncated at 255 characters. If the result of a custom text field formula is longer than 255 characters, then an error value will be displayed.