Mro Inventory
MRO (Maintenance, Repair, and Operations) inventory comprises indirect materials, spare parts, consumables, tools, and supplies used to maintain equipment uptime, safety, and regulatory compliance that are not directly incorporated into final products. It includes items like bearings, filters, lubricants, fasteners, PPE, and repairable components.
In a CMMS/Asset Reliability context, MRO inventory is managed by categorizing parts based on criticality (Vital, Essential, Desirable) to determine stock levels—often holding one unit for vital items and zero for others. Optimization involves part number rationalization to eliminate duplicates, setting Min/Max levels using the Asset Criticality Ranking (ACR) model, and calculating safety stock via Poisson distribution (for low variance) or bootstrapping (for high variance) based on 3-year consumption history. Demand forecasting predicts need timing and quantities to prevent stockouts (downtime) and overstocking (capital trap).
How is safety stock calculated for high-variance MRO items?
Use the bootstrapping technique to analyze consumption frequency/probability during lead time when daily variance exceeds 10% of the mean, then apply the standard normal distribution formula for the target service level.
What is the relationship between MRO inventory and reliability goals in CMMS?
EAM/CMMS applications must be customized to track performance data and meet specific reliability goals, integrating supply chain services, asset management, and master data leadership.
What is the 'Reorder Point' formula for MRO?
Reorder Point = Demand during lead time + Safety Stock (e.g., if lead time is 90 days, estimate units needed in 90 days plus a safety buffer).
How does part criticality determine stock levels?
Criticality is determined by factors like functionality, lead time, and lifecycle; Vital items get 1 unit in stock, while Essential and Desirable items may maintain zero stock.