SIM.JS

SIM.JS, a free discrete-event simulation package based on JavaScript

Original author(s)	Maneesh Varshney
Developer(s)	Maneesh Varshney
Stable release	0.26 / January 16, 2012 (2012-01-16)
Written in	JavaScript
Operating system	Cross-platform
Type	Discrete event simulation
License	LGPL
Website	simjs.com code.google.com/p/simjs-source/

SIM.JS is an event-based discrete-event simulation library based on standard JavaScript. The library has been written in order to enable simulation within standard browsers by utilizing web technology.

SIM.JS supports entities, resources (Facility, Buffers and Stores), communication (via Timers, Events and Messages) and statistics (with Data Series, Time Series and Population statistics).

The SIM.JS distribution contains tutorials, in-depth documentation, and a large number of examples.

SIM.JS is released as open source software under the LGPL license. The first version was released in January 2011.

Example

There a several examples bundled with the library download. Traffic light simulation is a standard simulation problem, which may be simulated as within this example:

function trafficLightSimulation(GREEN_TIME, MEAN_ARRIVAL, SEED, SIMTIME) {
   var sim = new Sim();
   var random = new Random(SEED);
   var trafficLights = [new Sim.Event("North-South Light"),
                        new Sim.Event("East-West Light")]; 
   var stats = new Sim.Population("Waiting at Intersection");
   
   var LightController = {
       currentLight: 0,  // the light that is turned on currently
       start: function () {
           sim.log(trafficLights[this.currentLight].name + " OFF"
                   + ", " + trafficLights[1 - this.currentLight].name + " ON");
           sim.log("------------------------------------------");
           // turn off the current light
           trafficLights[this.currentLight].clear();
           // turn on the other light.
           // Note the true parameter: the event must "sustain"
           trafficLights[1 - this.currentLight].fire(true);
           // update the currentLight variable
           this.currentLight = 1 - this.currentLight;
           // Repeat every GREEN_TIME interval
           this.setTimer(GREEN_TIME).done(this.start);
       }
   };

External links

• Anaylsis of the potential role of open source discrete event simulation software in the manufacturing sector issued by Proceedings of the Operational Research Society Simulation Workshop 2012 comparing SIM.JS among other open source simulation solutions
• Bachelor thesis on Web-Based Single-Player Project Simulation Game reviewing SIM.JS
• Interactive Model-Centric Systems Engineering report by Systems Engineering Research Center managed by Stevens Institute of Technology mentioning SIM.JS