A cost-balance exhibit contrasts ordering frequency with average inventory. A rotating replenishment wheel and a draining lot show why increasing order quantity shifts the two annual cost terms in opposite directions.
• A 3D laboratory scene with: Ordering-cost pan; Holding-cost pan; Cost balance beam; Lot depletion column; Replenishment cycle wheel. • Controls: Annual demand D (1000-10000 units/year); Cost per order S (20-200 currency/order); Annual holding cost H (1-10 currency/(unit·year)); Chosen lot size Q (50-2000 units). • Live readouts: Continuous optimum Q*; Annual ordering cost; Annual holding cost; Relevant annual total; Current sawtooth stock; Time between replenishments. • Guided experiments: Small lots; Large lots; Higher ordering cost.
• Q*=√(2DS/H) • Ordering cost=DS/Q; holding cost=HQ/2 • Relevant total=DS/Q+HQ/2 • Cycle=365Q/D days; inventory follows a Q-to-zero sawtooth • One animation second = 5 days.
Classical continuous EOQ with deterministic demand, instantaneous replenishment, no shortages and constant unit price. Purchase cost is excluded because it is independent of Q. No supplier pack rounding, discounts, lead-time risk or storage-capacity constraints. Currency is generic.
Annual ordering and holding costs. The derivative condition sets DS/Q = HQ/2.
No. The basic model has no stochastic demand or lead-time risk.
Ordering cost dominates and replenishment is frequent.
Classical continuous EOQ with deterministic demand, instantaneous replenishment, no shortages and constant unit price. Purchase cost is excluded because it is independent of Q. No supplier pack rounding, discounts, lead-time risk or storage-capacity constraints. Currency is generic.