Classifying a Measuring Point/Counter 
A list entry screen is displayed, in which you can enter the required classes.

You can only enter classes of a class type that allows the assignment of measuring points and counters.
This brings you to the characteristic valuation assignment screen for the respective class.
Enter the values for the entered characteristics, and return to the list entry screen for classes of the measuring point or counter.
For more information on the classification system, see the SAP documentation MM Classification System.