Minimum Reorder Quantity vs Economic Order Quantity: Choosing The Right Rule

Minimum Reorder Quantity is the smallest quantity that may be ordered when replenishing a product. Comparing MRQ to Economic Order Quantity (EOQ) clarifies whether you should order to a supplier minimum or to a calculated economic lot size that balances ordering and holding costs. Retailers often must decide between complying with supplier MRQs and optimizing with EOQ-based models.

EOQ is a theoretical lot size that minimizes the total cost of ordering and holding inventory given deterministic demand and constant lead time. MRQ is a real-world constraint that can force deviations from EOQ. Understanding the gap between MRQ and EOQ is essential to make operational and financial decisions that match your retail model.

What Each Measure Stands For

• MRQ: A contractual or physical lower bound on order size set by supplier or packaging.
• EOQ: A calculated ideal order quantity derived from demand rate, ordering cost, and holding cost.

Why The Distinction Matters

When MRQ exceeds EOQ, retailers accept higher carrying costs or seek ways to reduce order frequency or consolidate purchases. When MRQ is below EOQ, the supplier constraint is not binding and standard inventory optimization can proceed. The business implications influence working capital, markdown risk, and storage utilization.

How To Compare MRQ And EOQ Practically

• Calculate EOQ: Use the EOQ formula or a WMS/TMS that supports lot-sizing; factors are annual demand, ordering cost per order, and annual holding cost per unit.
• Gather MRQ Data: Confirm supplier pack sizes, agreed minimums, and lead time variability.
• Overlay Constraints: If MRQ > EOQ, model the increase in annual holding cost and impact on cash flow and service levels.

When To Accept MRQ Over EOQ

Accepting MRQ makes sense when supplier discounts, freight breaks, or vendor-managed inventory offset higher holding costs. For fast-moving SKUs, MRQ-driven lots may still approximate EOQ. For slow-moving or seasonal items, however, MRQ can create obsolescence risk — consider alternative sourcing or smaller package options.

When To Push Back Or Modify Operations

• Negotiate Smaller Lots: Use forecast-backed commitments or rolling purchase orders to reduce MRQs.
• Consolidate Across SKUs: Ask suppliers for mixed-SKU pallets that meet MRQ but lower per-SKU inventory.
• Implement Cross-Docking: Move MRQ shipments quickly through your DC to stores, reducing average on-hand age.

Decision Flow Example

Imagine EOQ for an accessory is 200 units, but the supplier MRQ is 500. Evaluate: discount offered at 500 vs unit cost at 200; storage cost per unit; expected sell-through in the replenishment cycle. If the 500-unit MRQ yields a supplier discount large enough to offset the holding cost, and you can redistribute stock across locations, accept MRQ. If not, negotiate or find alternate suppliers who permit smaller runs.

In short, the Minimum Reorder Quantity is a constraint that must be compared to EOQ to make informed ordering decisions. Use EOQ as a planning baseline and treat MRQ as a binding constraint to be negotiated or mitigated through sourcing and distribution tactics.