Do not confuse frequency of occurrence and failure rate
The frequency of failure occurrence mostly references the average number of failures observed in the course of a given period of time while the failure rate is represented by a function that can vary in time, and gives an instantaneous frequency of occurrence for a very short period of time. This instantaneous frequency of occurrence generally increases with time.
Knowing the statistical function that adequately represents the equipment failure rate is to know, at all times, its reliability function. Utilization of the frequency of occurrence rather than the rate of failure, allows one to obtain an average reliability factor for the period of time under consideration.
The calculation of the average intervals between two failures (MTBF) is often obtained from the frequencies of failure occurrences and not from the true failure rates. The difference is important and is often ignored in conventional reliability and maintainability analyses.
«PBM inc. determines the failure rate of your critical equipment from the data contained in your information systems».
Factors affecting failure rates
At the same time that failure occurrence frequencies are being measured over a given period of time, other effects and impacts are also being measured. These include the effects of how the maintenance policies are being applied, the impact of the efficacy rating of the preventative, or corrective, maintenance interventions that have been done, and the overall effect on the operational context. Consequently, it is often difficult to pinpoint the real causes of failure.
«The performance management approach used by PBM inc. allows you to distinguish, or single out the effect of each of the influence factors separately; thereby giving you the ability to prioritize improvement efforts and focus on where they are most needed.»
