A checklist to help your Organization identify your critical spares MRO inventory

Critical Spare Criteria

This form can be used to help decide if an item is a critical spare to be stocked. Criteria are weighed to make data driven vs subjective decision based on the risk tolerance of your organization. The form is broken into three main sections:

  • General Data (completed with support from Reliability Engineer)
  • Part Failure Criticality data
  • Usage, risk, carrying costs

General Date




Purchase price of an item

Lead Time

The number of days between ordering a part and receiving it

Delivery Cost

Expedited delivery fees

Part failure criticality data



Confidence in detecting failure before disruption

The % confidence level that the failure will be detected in the time given in the “time to Production Disruption” column.

Time to Production Disruption

Est. number of days between when failure is detected and/or the need for a spare is identified and when production will stop. If a site is using predictive technologies or has designed-in redundancy, the warning window will be larger.

Criticality Score

The asset’s criticality score. This will be combined with how easy the part is to procure and attain, how early failure can be detected and it’s cost to arrive at an MRO criticality score. Score from 0-100.

MRO Criticality

Spare criticality ranking that consider the asset’s criticality score, part availability, failure detection confidence and cost factors. Score 0-100.

Carrying Cost

The total cost of carrying inventory. This can include storage, distribution, security, insurance, taxes, damage, spoilage, obsolescence and/or the cost of money. Calculated by multiplying a % by the total value of your inventory.

Usage, risk, carrying costs



Estimated annual usage

The approximate number of times the part will be expected to fail within one year. Thus can be forecast and/or based on historical data.

# of parts in use

Number of components used throughout the facility.