The final lesson states the boundary: this is deterministic inventory-position arithmetic.

highlighted = computed this step

Exact rule

The exact rule uses reorder point 10 and order quantity 12.

rule: order when positionR\text{rule: order when position}\le R
Lead-time receiptThe chart shows deterministic lead-time demand, safety stock left, and receipt.lead-time receiptR = 6 + 4 = 10inventory position checksnapshoton handon orderbackorderspositiondecisionexample day812020waitlater100010orderlead-time arithmeticdemand 6safety left 4start 10receipt +12after receipt 16deterministic demand and lead time only

Constant inputs

The model assumes constant demand rate and constant lead time.

constant demand and lead time\text{constant demand and lead time}
Lead-time receiptThe chart shows deterministic lead-time demand, safety stock left, and receipt.lead-time receiptR = 6 + 4 = 10inventory position checksnapshoton handon orderbackorderspositiondecisionexample day812020waitlater100010orderlead-time arithmeticdemand 6safety left 4start 10receipt +12after receipt 16deterministic demand and lead time only

Not modeled

It does not model service-level probability, lead-time uncertainty, lost sales, or demand forecasting.

outside scope: uncertainty and lost sales\text{outside scope: uncertainty and lost sales}
Lead-time receiptThe chart shows deterministic lead-time demand, safety stock left, and receipt.lead-time receiptR = 6 + 4 = 10inventory position checksnapshoton handon orderbackorderspositiondecisionexample day812020waitlater100010orderlead-time arithmeticdemand 6safety left 4start 10receipt +12after receipt 16deterministic demand and lead time only

Honesty note

This is deterministic constant-demand, constant-lead-time arithmetic only. It does not model service-level probability, lead-time uncertainty, lost sales, or demand forecasting.

deterministic inventory-position arithmetic only\text{deterministic inventory-position arithmetic only}
Lead-time receiptThe chart shows deterministic lead-time demand, safety stock left, and receipt.lead-time receiptR = 6 + 4 = 10inventory position checksnapshoton handon orderbackorderspositiondecisionexample day812020waitlater100010orderlead-time arithmeticdemand 6safety left 4start 10receipt +12after receipt 16deterministic demand and lead time only