Number Of Methods Inherited (NMI)

Overview

Amongst the operations inherited by a class, the number of those which are not redefined must be relatively greater than that of those which are redefined.

Computation

For a class, this metric gives the percentage of the number of non-redefined operations with regard to the number of operations inherited.

The ... variable	represents the ...
NOHO	number of non-redefined inherited operations
HOP	number of inherited operations

Nominal range

Between 50 % and 100 %

Analysis

The percentage of operations inherited should be high. This is the opposite of the Number of Methods Overridden (NMO) threshold. A low percentage of inherited operations indicates poor sub-classing.

The maximum of 100 % is ideal, but is never attained, given the fact that we often need to adapt inherited services.