This model is based on the concept that the failure rate of a pair of mated connectors in the operational mode depends on the number of active pins (or contacts), the operational environment in which it is being used and also upon the frequency of making and breaking (cycling) the male and female halves. The failure rate model for a pair of mated connectors is:

Where:

λp= The predicted operational failure rate (in failures per 106 hours) of a pair of mated connectors under stated environmental and operating conditions.

λB= The operational base failure rate of the particular type of connector in the ground fixed environment (Table A-1).

KE= The environmental factor appropriate to the operational environment of the connector (Table A-1).

Kp= The active pin (or contact) factor appropriate to the number of active pins ( ) in the connector (Table A-37).

NP= The number of active pins (or contacts) in the pair of connectors.

λcyc= The cycling failure rate appropriate to the number of cycling operations per 1000 operating hours (Table A-36).