Introduction
- PDEVS formalism:
- mathematical description of complex discrete systems
using components
- method and book (Zeigler et al.) widely popular
- but: not used in standard simulation
environments
- Basic obstacle for practical PDEVS use:
- uses Moore architecture (output depends on state,
not on input)
- Mealy only via transitional states
- → changes the expected order of concurrent
events
- → makes description complicated
- → behaviour of such components depends on
context
- serious drawback for a library of reusable
blocks
- RPDEVS:
- "revised" PDEVS by Preyser et al.
- basic goal: make PDEVS fit for real-life
libraries
- allows for Mealy-like behaviour directly
- changes the way chains of concurrent events are
handled
- notoriously difficult problem, needs more
analysis
- Therefore:
- test PDEVS and RPDEVS with a crucial example
- has problems in RPDEVS → find a scheme that
might work (NSA-DEVS)
- NSA-DEVS should make handling of concurrent
events as clear as possible
- check that it works