The formula, in words
Declared cover at one location is its demand rate multiplied by its cover days. The proportional rule gives each location the same share of arrival as its share of total demand. The equal days rule raises the lowest post allocation days of cover together, stops each location at its own cover, and leaves any excess unused. where Ci is declared cover in units, di demand per day, and ci cover days. where ai is the proportional allocation, Q arrival units, and j each location in the total. where bi is the equal days allocation, λ the common cover level in days, and si stock on hand. A worked example
- Three locations each use 100 units a day, start with 0 stock and declare cover of 2, 6 and 6 days. The arriving quantity is 600 units and the rule is equal days.
- The first location needs 200 units to reach its 2 day cover. The remaining 400 units raise the other 2 locations to 2 days each.
- Two locations remain below their declared 6 day cover. The first short name is B because B is the second row and comes before C in the typed order.
What this does not model
The proportional rule does not reassign a share after one location reaches cover. The equal days rule does not use units beyond all declared cover.
Demand not entered, transit timing, pack constraints, minimum drops and service consequences are outside the arithmetic.
The count and first name do not rank locations, judge fairness or form a cut list.
What the sweep holds fixed
Only arrival moves. Every location row and the selected rule stay fixed while all 61 quantities from 0 through 12,000 are checked in steps of 200. Identical tracked answers are compressed into bands without interpolation.
Source basis
The two declared rules use standard proportional allocation and water filling arithmetic from public distribution and inventory mathematics. No private source wording is reproduced, and the selected rule comes only from the control on this page.