Using component-based discrete-event modeling with NSA-DEVS – an invitation

Introduction

Discrete-event modeling:
- many commercial modeling/simulation environments available
  - wide range of components
  - helpful tools
- model behaviour sometimes unexpected
  - documentation not sufficient
  - behaviour of components not defined completely
- precise definitions are essential
DEVS formalisms:
- precise mathematical description of Discrete-EVent Systems
  - single components (atomic models)
  - hierarchical system of components (coupled models)
  - exact behaviour of models (simulator)
- PDEVS (Parallel DEVS)
  - widely used
  - has problems with reusable Mealy components
- RPDEVS (Revised PDEVS)
  - direct description of Mealy components
  - has problems with chains of concurrent events
- NSA-DEVS (Non-Standard Analysis DEVS)
  - uses Mealy description from RPDEVS
  - adds infinitesimal delays to cope with concurrent events
  - has shown to work in many examples
  - free Matlab implementation of simulator and component library