Everything you need to model a line, find the constraint, and prove the payback — online, in your browser.
Event-driven simulation of stations, buffers, parallel stages, conveyors and operators. Validated against M/M/1 queueing theory within ~2%.
Identifies the true constraint, decomposes capacity, and applies Theory-of-Constraints reasoning to what to elevate first.
Breaks availability/performance/quality losses into a per-year money waterfall so you fix the expensive losses first.
Paired runs with common random numbers isolate your change from luck — and print its payback.
Parameter sweeps with main-effects, standardized-effects Pareto, and an optimization point with constraint-elevation advice.
Payback, ROI, NPV and IRR on a single page — turn an operations change into a financial decision.
Component feeder lines and multi-product recipes/campaigns model the real bill of materials, not just a single flow.
Cycle-time distributions (Normal, and more), breakdowns, jams, starvation and blocking — realistic, not deterministic.
Opens in any modern browser, always the latest version. The simulation computes on your machine — your line model stays with you.
Stations, buffers, parallel stages, conveyors, operators and component feeders — configured in modals, no code.

Watch flow, jams, starvation and blocking — or run without animation for speed, with statistical distributions on every cycle.

Set up scenario A vs B, or sweep parameters with a full-factorial DOE to find the best configuration.

The executive one-pager and financial study price everything per year and tell you the payback — exportable to PDF, CSV and Excel.

RASQI is a focused discrete-event simulator for serial and assembly production lines, not a general-purpose modeling platform. That focus is why anyone who knows the line can run it in minutes — and it means some line types sit outside its scope. Here's the honest boundary, so you can tell before you buy.
Your line somewhere in between? Tell us about it — we'll say honestly whether RASQI fits as-is, or scope a customization for your specific process.
The free trial is the real app. Open it in your browser and run your line in 10 minutes.