Watch a simulation actually run
A discrete-event model is usually a table of numbers at the end of a run. It doesn't have to be. Every animation on this site is a real KSL run, replayed in your browser — no install, no plugin, no video.
A drive-through pharmacy: cars arrive, wait in one line, and are served by whichever pharmacist is free. Press pause — it is a simulation being replayed, not a clip.
It is the model you already wrote
Animation is not a second implementation of your simulation. You do not describe the picture to the simulator or the simulator to the picture. Capture is a flag on a run: the model executes exactly as it always did and writes down what happened, and everything on this site is drawn from those recordings afterwards.
That matters more than it sounds. An animation built by hand can disagree with the model, and when it does, it lies convincingly. One replayed from the run cannot.
Three steps
Capture
Run the model with capture switched on. It writes a trace — every arrival, seize, move and release, with the time it happened.
Lay it out
A layout says where a queue sits and what color an entity is. You do not start from a blank canvas: the app derives one from the trace, and you adjust what it guessed.
Replay
Scrub, pause, slow it down, run it back. The trace is a file — keep it, send it to a student, open it again next year.
The same picture in two places
The desktop application and this website draw through one renderer over one trace format. A page here is not an export or an approximation of what the app shows; it is the same drawing code reading the same file. Each animation below offers its trace for download, so you can open it in the app and lay it out yourself.
What it can draw
Queues and resources
Lines forming and clearing, servers busy and idle, blocking when a buffer fills.
Movement
Parts on conveyors, workers carrying loads, vehicles routing around congestion.
Agents in space
Crowds through doorways, epidemics across a grid, flocking on a world whose edges join.
Live statistics
Charts and counters that advance with the run, beside the thing they are counting.
Have a look
Fifteen worked examples, from a single queue to a warehouse of bidding vehicles. Each one says what it is and what to watch for while it plays.