A model of systems and projects (Part I)

Modelling of systems and projects by various types of nets is a good tool to deal with such features of systems as concurrence, reliability, cost, etc. Nowadays there exist numerous methods of modeling. The most popular seem to be such methods as PERT, GERT, CPM for analysis of projects, and Petri nets, event structures or discrete event systems for cyclically working systems. In the paper, a common graph-theoretic base for modelling of systems and projects-graphs with limitations is proposed. The proposed model is more general than Petri nets and the corresponding morphisms seem to be a good tool for refinement of such models of systems. In this part of the paper, the notion of a graph with limitation is described.