Supply Pulse
Why does a 25% rise in demand make a plant swing its output by more, run short for weeks and then overshoot? Supply Pulse shows how the delays of a packaged food and dairy supply chain (forecasting, hiring, QA release and shipping) turn reasonable decisions into amplification, shortages and expired stock, and what each lever really costs. In English, Spanish or Danish.
What it does
- Shocks the chainA lasting change in demand, a seasonal surge or a plant outage, with random week-to-week variation that the baseline shares, so comparisons are fair.
- Models what is specific to food and dairyQA release that takes weeks and rejects some batches, shelf life tracked first-in, first-out with a minimum remaining life at delivery, and a workforce that takes time to hire and qualify.
- Adds the rest of the chainA distributor that orders from the plant, and an ingredient supplier far upstream, so you can see where amplification starts, what sharing sales data changes and where a buffer is cheapest.
- Runs a real plantA line shared in campaigns with changeovers, a QA lab that can become the bottleneck in a surge, and customers who are critical or not, with a rule for who goes short.
- Weighs the leversOvertime, expedited QA and the planning policy (cover, forecast, correction speed and the weight on the supply line), measured on profit, fill rate, bullwhip and waste against a saved baseline.
- Supports the decisionA decision lab: scenarios side by side, 100 demand futures with the range of outcomes, a tornado of what matters most, and an optimiser that searches the planning policy. A printable decision report, and your own demand data in place of a pattern.
- TeachesA tutorial in three levels, a play mode where you are the planner, a live stock-and-flow diagram and every equation with its value in any week.
How it is built
The model is a set of stocks and flows integrated week by week in small time steps, in plain JavaScript that runs entirely in your browser. Automated tests check that it starts in exact balance, that every case is accounted for, that a smaller time step gives the same answers, that the forecast matches its exact solution, and that each lever produces the trade-off the tutorial claims. Every claim the tutorial's questions make is checked against the model too.
Author
Supply Pulse was designed and built by Daniel Alberto Sepulveda Estay, PhD, founder of Estay Dynamics. He works on system dynamics, simulation and network optimisation for supply chains and operations. He holds a PhD from the Technical University of Denmark (DTU) and a master's degree from the Massachusetts Institute of Technology (MIT), and is a council member of the System Dynamics Society.
To cite: Sepulveda Estay, D. A. (2026). Supply Pulse: a food and dairy supply chain simulator (version 4.1.0) [Software]. https://kathuman.github.io/supply-pulse/