Count Unique values based on another column

[longstick]

I've seen many solutions for this question but still haven't been able to get it to work for myself.

I am looking for the number of tools on a process. Tooling is identified by a serial number in column A. The process is identified by the Process name in column B.

In the end I would like to know that Process 1 has 2 tools, Process 2 has 4 tools, etc...

Thanks,

 

[Aladin Akyurek]

I've seen many solutions for this question but still haven't been able to get it to work for myself.

I am looking for the number of tools on a process. Tooling is identified by a serial number in column A. The process is identified by the Process name in column B.

In the end I would like to know that Process 1 has 2 tools, Process 2 has 4 tools, etc...

Thanks,

E2: Process 1
E3: Process 2

F2, control+shift+enter, not just enter, and copy down:

=SUM(IF(FREQUENCY(IF($A$2:$A$400<>"",IF($B$2:$B$400=$E2,
     MATCH("~"&$A$2:$A$400,$A$2:$A$400&"",0))),
     ROW($A$2:$A$400)-ROW($A$2)+1),1))

If there are no special meaning chars like < around the entries in the A range, the "~"& and &"" bits can be omitted from the formula.