CAOS SimLab — A Didactic Lab for Simulation (DES & ABM)
Published:
An open, didactic lab for Discrete-Event Simulation (DES) and Agent-Based Modeling (ABM). Instead of a toy script or a GUI that hides the model, you arrive directly in a running simulation, move the sliders, and watch the dynamics change — across ten worked scenarios, with a from-zero curriculum that teaches the real tools (SimPy, Mesa, OR-Tools). Live at simlab.fasl-work.com.
Two lanes, decided by measurement
A run is a pure function of (params, seed) that produces a compact trace; the front end only animates it, so live and precomputed render through one code path — replay is truth. A measured 3-gate rule (pure-Python and under 3 s and trace under 1 MB) decides the lane:
- Live — light scenarios run in your browser via Pyodide; edit parameters, re-run, watch it animate. No server, nothing to install.
- Precomputed — heavy scenarios (native solvers like OR-Tools, large agent counts) are run offline into a seeded trace and replayed with a timeline scrubber under a clear “precomputed due to cost” banner.
Honest simulation
The lab teaches what most demos skip: a single run is noisy, so results come from replications + confidence intervals; steady-state metrics need a warm-up cut; the same seed must reproduce the same result; and an animation is a hypothesis generator, not evidence. Each scenario validates against theory or a baseline where one exists — the M/M/c queue against the closed-form Erlang-C.
Coverage
Ten scenarios across six visualization families (queue · agent-grid · chart · flow · gantt · route): bank/clinic queue, Schelling segregation, SIR epidemic, ED patient flow, the beer game, job-shop scheduling, construction haul routing, vehicle routing, ambulance dispatch, and a Monte-Carlo/CI study.