RELATIONS AS OBJECT MODEL COMPONENTS

Although object-oriented methods make extensive use of relations betwe en objects, these relations, other than inheritance and part-of, canno t directly be represented by the conventional object-oriented model. T his means that relations which are identified during analysis and desi gn have to be implemented on top of the object model, i.e. by using me thod code and message passing, rather than by expressing relations dir ectly within the model. It would be beneficial if the object oriented model would support the specification of all relevant types of relatio ns within the model, including application-domain specific relation ty pes. Therefore, we propose a mechanism, implemented in LAYOM-an extend ed object model, that supports the specification of all types of relat ions between objects within the model as components of the object mode l. In addition, an approach for identifying and specifying application -domain relation types is presented.