When you define an
The following equation is used to calculate FFI:
FFI = MTIVE x [(n + 1)(MTED)/MMF]1/n
Note that the information used for the FFI calculation is based upon the concepts in SAE Standard JA1012, "A Guide to the Reliability-Centered Maintenance (RCM) Standard." The process and terminology used in the FFI calculation are described in more detail in this standards document. To use the Failure Finding Activity cells effectively, you will need to be familiar with this standard.
In addition, the FFI calculation is based upon information in the book "Reliability-Centered Maintenance" by John Moubray.
The following table describes the Failure Finding Activity cells in the GE Digital APM Framework.
Cell |
Description |
---|---|
MMF |
Stores the mean time between multiple failures. For example, a 1 in 1,000,000 probability of a multiple failure in one year implies a mean time between failures of 1,000,000 years. The probability of multiple failures occurring in any one year is 1/MMF. |
MTIVE |
Stores the mean time between failures of the protective device. |
MTED |
Stores the mean time between failures of the protected function. For example, if the demand rate of the protected function is once in 200 years, this equals a probability of failure for the protected function of 1 in 200 in any one year, or a mean time between failures of the protected function of 200 years. The probability of failure of the protected function in any one year is 1/MTED. |
n |
The number of protective devices. |
Copyright © 2018 General Electric Company. All rights reserved.