Item Failure Rate
The failure rate (FR) for an item in the FMEA Worksheet table indicates the number of times it is likely to fail over some time period. The item FR is calculated when FMEA results are calculated. The item FR uses the failure rate multiplier when it is shown. If Item Failure Rate Percentage is blank, a value of 100% is assumed.
• In a component FMEA, the item FR is calculated at the item level based on linked prediction data. The equation for calculating the item FR for a part or assembly is:
The predicted FR comes from the part or assembly to which the item is tied.
• In a functional or process FMEA, the item FR is calculated at the item level for linked items based on the FR data for the linked items. The equation for calculating item FR for a linked item is:
The linked FR is the FR of the record to which the FMEA part or assembly is linked.
◦ In a functional or process FMEA, you must specify the item FR for a non-linked item. When an item is not linked, the item FR percentage is not used.
◦ In a functional or process FMEA, when considering the FR for subassemblies, you must enter a failure rate percentage so that the item FR can be calculated. The value that you enter represents the percentage of the total subassembly FR that applies to this specific item.