Net system morphisms and observability in system design

The process of specifying distributed systems in terms of elementary net (EN) systems, a class of Petri nets, can be supported by conceptual tools like morphisms and preorders, together with state observability. These concepts allow the designer to build system descriptions at different levels of detail and to compare them in a sound way. The approach is that understanding some problems and finding some solutions within basic net system models (i.e., not dealing with data structures) can be of help in finding understanding problems and finding solutions in the high level net framework. The EN systems whose behavior is represented by local state transformation algebras defined together with the morphisms supporting the comparison between them and the notion of observability of states. The author illustrates the use of the conceptual tools in system design.<>