Hierarchy of System Specification

11 February 2005. Ernesto Posse.

This talk presents a very brief introduction to some general theoretical aspects of Modelling and Simulation. We focus on dynamic systems and show different levels of specification and abstraction for modelling such systems. We present the concept of hierarchies of system specification, and discuss some alternative hierarchies. The notion of system morphism as a means to relate systems either at the same level or at different levels is introduced. Special attention is paid to some behavioural morphisms, specifically (bi)simulation. Abstraction, refinement, and correctness are defined in terms of these morphisms.