Inventory & Threshold Accumulation

Abstractions about managing stock and exposure against thresholds — reorder policies like min-max inventory and economic order quantity, failure events like stockouts, concentration risk in supply dependencies, and cumulative-dose accumulation that crosses a threshold no single event would.

5 abstractions in this family — domain-specific abstractions that sit near one another in structural-signature space (k-means over structural-signature embeddings). Each is shown with its short description.

• Cumulative Dose — Locate biological harm or benefit in the time-integral of an exposure stream rather than any single event, so a course of individually safe doses can still cross a threshold on the running stock — which reducing the present rate cannot undo.
• Economic Order Quantity — Find the replenishment batch size minimizing total cost by summing a per-event ordering cost that falls with batch size and a per-unit-time holding cost that rises with it, giving a U-shaped curve whose flat-bottomed optimum is √(2DK/h).
• Min–Max Inventory — An inventory policy that manages stock inside a declared band — replenishing up to a maximum ceiling only once on-hand falls to a minimum reorder point, and doing nothing in between — collapsing continuous order decisions into two scalars per item.
• Stockout — Pin inventory's central failure to a precise binary event — on-hand stock for one SKU at one location reaching zero while demand still arrives — whose heterogeneous, mostly-unobservable cost, weighed against holding cost, drives every safety-stock and service-level decision.
• Supplier Concentration Risk — Exposure that arises when a buyer's dependency for a critical input rests on so few suppliers that one node's disruption propagates downstream faster than alternatives can be qualified — a shape property of the dependency distribution, not of any supplier's performance.