AbstractThe Jackson methodology for systems development is seen as a formal methodology. Although it is formal, the analyst has a freedom to specify models of problems in alternative ways without giving any indication which one is the better. Proposals to extend the methodology with the concepts ‘(near) static entity’ and ‘static roles’ give the analyst even more freedom than before. From the maintenance point of view this can lead to problems of understandability of the models. Also some enhancements cannot be done without completely redesigning entities. In this paper we propose to separate the existence aspect of an entity in one process. A second proposal is to model relationships (i.e. aspects comon to two or more entities) between entities explicitly using entity‐relationship notation. In this way, more maintainable specifications will be