The primary consideration in maintenance, repair, and operating (MRO) supply systems typically is:

Maintenance, repair, and operating (MRO) supply systems are systems that manage the inventory and procurement of the items that are used to support the production process, but are not part of the final product. MRO items include spare parts, tools, lubricants, cleaning supplies, safetyequipment, and office supplies. The primary consideration in MRO supply systems typically is stockout costs. Stockout costs are the costs associated with the inability to meet the demand for an item due to insufficient inventory. Stockout costs can include lost sales, customer dissatisfaction, production downtime, emergency orders, and reputation damage. Stockout costs can be very high for MRO items, especially if they are critical for the operation and maintenance of the production equipment. Therefore, MRO supply systems should aim to minimize the risk of stockouts by ensuring adequate availability and accessibility of MRO items.

References: CPIM Exam Content Manual Version 7.0, Domain 5: Plan and Manage Inventory, Section 5.2: Implement Inventory Plans, Subsection 5.2.3: Describe how to implement inventory replenishment techniques (page 46).