The “Logical” option sets that code part B, C, D, E etc. to be mapped to the Maintenance object attributes, Cost Center, Object, and Project.   

Long ago, those were hard coded, Code B needed to be used with cost center.  The logical function changed that.  Now nearly any code part can be used as a cost center and any code part marked as logical code part cost center, those code part values will show in the maintenance object cost center attribute. 

Best regards, 

Tom

To continue with the above, if your using IFS Maintenance, it’s important, else, it is not.  Typically, I would always use that setting as we don’t know if someday IFS Maintenace would be used.  I’m unaware of any downside of setting it up and never using it.