Ranking the complexity of NIAM conceptual schemas by alpha metric

The general aim of formal methods to program development is to provide correctness of the problem specification and then to transform that specification into a working program. Often a formal specification is expressed using the NIAM conceptual schema. If we consider only valid types of constraints and if we keep all the consistent schemas, we have 28 possible schemas and 7 sub -- schemas for each schema. The schemas and sub - schemas have very different complexities and there exists an intuitive order of these complexities which seems to be problematical. The aim of this paper is to verify this order using a complexity measure called α (information content/entropy metrics) and to define a new ranking functions generating more correct order.