Lifetime dependency : an abstraction relation for modelling roles, symbolic substance, and relations with attributes

Abstract

Techniques for analysis aim at diminishing the gap between users' concepts of the problem domain of computer systems and the computers' requirements for algorithmic and structural precision. This paper aims at improving techniques for analysis through suggesting a new type of relation between objects. We have defined a new abstraction relation called lifetime dependency: when an object (the dependent) throughout its lifetime depends on the existence of other objects (the support), the dependent stays in a lifetime dependency to the support. Three typical cases of lifetime dependency are when a person has several roles, when symbols are inscribed in a substance, and when relations with attributes or life cycles depend on the existence of the objects connected by the relation. The paper shows that lifetime dependency captures such relations better than any previous mechanisms proposed for modelling subsets of this relation. The previous approaches solved some of the modelling problems, but they often introduced other problems instead, eg, creating additional types of objects or restricting the possibility to express cardinalities. The transition between analysis and design of lifetime dependency is discussed, and guidelines for analysis are provided.

6th Australasian Conference on Information Systems (ACIS'95) September 27-29, 1995