failure rate
Technical term used in engineering, reliability analysis, and quality control to express the proportion of items that fail within a given period.
The failure rate of this component is very low.
We reviewed the design to reduce the failure rate.
不良率 refers to the defect rate in manufacturing (proportion of defective items), whereas 故障率 focuses on failures over time during operation.
Compound of 故障 (failure, breakdown) and 率 (rate, proportion).