DEVS
Sign in to saveDEVS, abbreviating discrete event system specification, is a modular and hierarchical formalism for modeling and analyzing general systems that can be discrete event systems which might be described by state transition tables, and continuous state systems which might be described by differential equations, and hybrid continuous state and discrete event systems. DEVS is a timed event system.
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Article
63 sectionsContents
- History
- Formalism
- Intuitive example
- Atomic DEVS
- Coupled DEVS
- Analysis methods
- Simulation for discrete event systems
- Simulation for continuous state systems
- Verification for discrete event systems
- Timed event system
- Variations of DEVS
- Extensions (superclassing)
- Restrictions (subclassing)
- Behavior
- Atomic DEVS<span class="anchor" id="Behavior of Atomic DEVS"></span>
- View 1: total states = states * elapsed times
- View 2: total states = states * lifespans * elapsed times
- Comparison of view1 and view2
- Features of view1
- Features of view2
- Coupled DEVS<span class="anchor" id="Behavior of Coupled DEVS"></span>
- View1: Total states = states * elapsed times
- View2: Total states = states * lifespan * elapsed times
- Time passage
- For view1
- For view2
- Simulation algorithms
- Atomic DEVS <span class="anchor" id="Simulation Algorithms for Atomic DEVS"></span>
- Common parts
- View 1: total states = states * elapsed times
- View 2: total states = states * lifespans * elapsed times
- Coupled DEVS <span class="anchor" id="Simulation Algorithms for Coupled DEVS"></span>
- FD-DEVS
- History
- Examples
- Ping-pong game
- Two-slot toaster
- Atomic FD-DEVS
- Formal definition
- Behaviors of FD-DEVS models
- Advantages
- Applicability of time-zone abstraction
- Reachability graph
- Decidability of safety
- Decidability of liveness
- Disadvantages
- Weak expressiveness for describing nondeterminism
- Tool
- For verification
- For simulation via XML
- SP-DEVS
- History
- Crosswalk controller example
- Atomic SP-DEVS
- Formal definition
- Behaviors of a SP-DEVS model
- Advantages
- Disadvantages
- Tools
- See also
- DEVS-related articles
- Other formalisms
- References
DEVS, abbreviating discrete event system specification, is a modular and hierarchical formalism for modeling and analyzing general systems that can be discrete event systems which might be described by state transition tables, and continuous state systems which might be described by differential equations, and hybrid continuous state and discrete event systems. DEVS is a timed event system.
==History== DEVS is a formalism for modeling and analysis of discrete event systems (DESs). The DEVS formalism was invented by Bernard P. Zeigler, who is emeritus professor at the University of Arizona. DEVS was introduced to the public in Zeigler's first book, Theory of Modeling and Simulation in 1976, while Zeigler was an associate professor at University of Michigan. DEVS can be seen as an extension of the Moore machine formalism, which is a finite state automaton where the outputs are determined by the current state alone (and do not depend directly on the input). The extension was done by associating a lifespan with each state, providing a hierarchical concept with an operation, called coupling,