Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Technical Specifications
10-74 Issue 3 June 2001
Infant Mortality 1 0
Telcordia Technologies requires that the number of circuit pack failures in the first
year of operation should not exceed 2.5 times the number of failures per year
beyond the first year. The ratio of first year failures to failures in subsequent years
is known as the infant mortality factor (IMF). The requirement is to have an IMF of
less than 2.5
*
.
DDM-2000 OC-3 Multiplexer circuit packs are subjected to an environmental
stress testing (EST) program. The purpose of the program is to eliminate early life
failures, conduct failure mode analysis on defective circuit packs, and use
corrective action to make the product more reliable. All new circuit pack codes in
manufacturing are subjected to EST. However, based on field return data, when
the early life failures for any circuit pack codes have been minimal and the infant
mortality factor is below 2.5, these circuit pack codes may be subjected only to
sampling EST.
* TA-NWT-000418, Issue 3, November 1991, p. 40.