MRO spare parts planning
Plan stock around service risk, not averages alone.
Separate expected demand, uncertainty buffers, order quantities, and criticality. Formula output is an input to a replenishment policy, not the policy itself.
Exposure
Lead-time demand
Expected use before replenishment arrives.
TriggerReorder point
Lead-time demand plus safety stock.
BufferSafety stock
Demand variation buffer.
Order policyEOQ
Ordering and carrying cost balance.
Store healthInventory turnover
Annual movement of inventory value.
Criticality changes the answer.
Intermittent demand and high outage consequence can make a purely statistical setting unsafe. Combine formulas with failure mode, installed base, shelf life, repairability, and supply recovery review. Read MRO safety stock planning.