It is important for us to measure the features of various information models (IMs), because it will give us the opportunity to distinguish which models that are more complicated than others. With this measure it is also possible to estimate for example, the lines of code in the implemented product and the cost and time effort needed to make the product. It is also possible to discover which parts of the model that are most complex and thereby know which part that will need the most time to implement. The IM Meter is able to measure the significant properties of various information models such as complexity and information content. The measures the IM Meter deals with are of various sorts. Some of them measure the features of minor details of the information models while other measure more general and extending properties. The present paper considers telecommunications management network (TMN) interface complexity in particular