Reorder Point & Safety Stock Lab (2D)

This 2D companion runs the same reorder-point inventory theory as the 3D version through a plain canvas line chart built for reading the statistics: mean demand, a Poisson-vs-Gaussian demand-model switch, lead time and target service level (z) all feed a rolling 30-day forecast that recomputes the safety-stock buffer (SS = z·σ·√L) and reorder point (ROP = μ̂·L + SS) every simulated day, while an Economic Order Quantity toggle balances real ordering cost against holding cost. Watch stock dip through the orange reorder line, a purchase order fire and arrive after the lead time, and red stockout columns appear whenever the day's random demand outruns the safety buffer you configured.