Discrete-event simulation software

Simulation modeling based on a discrete-event approach is called discrete-event simulation.

Discrete-event simulation is an effective way to obtain system characteristics when analytical methods are insufficient — either no exact formula exists, or the computation is too slow to be practical.

Computer simulation software using discrete-event simulation is used in

traffic simulation,
network simulation,
emergency evacuation modeling,

and many other fields in science, engineering, and education.

Two styles of simulation

The OpenSIMPLY is scientific software for researching both simple and large, complex systems.

It is good for users with any modeling experience and supports both engineering and educational use.

The source code is currently compatible with Object Pascal dialects such as Delphi and Free Pascal (Lazarus) and can be modified from the application level down to the kernel.

OpenSIMPLY offers two simulation styles: block simulation and Simula-like simulation.

Block simulation

This high-level approach does not require knowledge of the implementation of discrete-event simulation, but just a basic knowledge. You simply connect ready-to-use blocks and set their parameters. Each block represents a complete modeling component. Here is a model of an M/M/C queueing system in terms of block simulation:

In this example

the Generator block represents the source of entity flow,
the Queue represents the waiting line,
the Server represents the time delay during servicing,
the Selector represents the distributor of entities between servers.

Blocks are fully extensible: you can add custom parameters, functionality, distribution laws, selection rules, or create entirely new blocks.

Explore queuing theory simulation examples to see how OpenSIMPLY works.

M/M/C queue system in terms of block simulation

Simula-like simulation

This low-level approach follows the ideology of the Simula programming language. It provides maximum flexibility for describing any system behavior.

Key mechanism: activation and suspension of processes. Models run significantly faster than in block simulation. Even adapted Simula models can be run in OpenSIMPLY.