Occurrence is a rating corresponding to the likelihood that a particular failure mode will occur within a specific time period.
Note: Controls can be used to prevent or minimize the likelihood that failure cause(s) will occur. In this event, the presence or application of the control should be considered when estimating the Occurrence rating.
For each cause listed in Column 14, estimate the possible failure rates and/or mean time between failure.
The occurrence of failure can be based upon historical data, including the service history, warranty data, and maintenance experience with similar or surrogate parts.