Failure rate

The analysis of parts and components to predict the rate at which an item fails. In parts count prediction, the expected or known failure rates for all components within an item are tallied to estimate the item’s overall failure rate. (However, this method is proven to be very inaccurate at estimating the actual field failure rate.)

The mathematical and/or graphical analysis of time-to-failure data of items in use by customers. Analysis of field data enables an estimate of the actual field time-to-failure distribution or failure rate.

1) an equivalent activation energy for use with complex structures (IC for example) to estimate the time to failure distribution. 2) a calculated activation energy using the relationship between stress and failure rate (empirically derived) representing the relationship between the applied stress and time-to-failure for a specific failure mechanism.

The fraction of units that have failed referenced to the survivors (not to the initial number of units). The value of this function at a specified time t₁ is given by the integral of the instantaneous failure rate (hazard rate), h(t), from t = 0 to t = t₁.

The failure rate within the defined duration of early life.