Assessing the quality of abstract data types written in Ada

A method is presented for assessing the quality of ADTs (abstract data types) in terms of cohesion and coupling. It is argued that an ADT that contains and exports only one domain and exports only operations that pertain to that domain has the best cohesive properties, and that ADTs that make neither explicit nor implicit assumptions about other ADTs in the system have the best coupling properties. Formal definitions are presented for each of the cohesion and coupling characteristics discussed. Their application to Ada packages is also investigated, and it is shown how a tool can be developed to assess the quality of an Ada package that represents an ADT