|IF statements really bring power to your spreadsheets. And multiple IFs, even more so.
There are two main problems:
Firstly, they can get very difficult to understand, particularly if you are working on someone else’s spreadsheet, or even your own if you come back to it after several months.
Secondly, because of the simple layout of IF [IF(test, action if TRUE, action if FALSE)], where only a comma separates each term, it is easy to get confused.
If you’re lucky, Excel won’t accept the mistake.
Unfortunately if the formula is logically correct it will be accepted, but with unexpected results.