Appendix E. Reliability
179
Electronic Equipment Procedure
Other methods may be used to estimate the reliability of certain products and/or subsystems.
System reliability predictions take into account the impact of redundant components.
Component Parameters and Assumptions
The default methodology for MTBF predictions is Telcordia method 1, case 3.
Assumptions include 25
˚ C system inlet air temperature, quality level II components, ground
-
based, fixed, controlled environment, and 100% duty cycle. Components internal to the system
are generally assumed to be operating at 40
˚ C ambient and 50% electrical stress.
Supplier MTBF Data
In developing system MTBF predictions, VIDYO uses MTBF data provided by suppliers.
Apart from using industry standard prediction methodologies, suppliers may derive MTBF data
from reliability demonstration testing, life testing, actual field failure rate, or specification and
datasheets.
Supplier data is provided as is to VIDYO, and VIDYO generally does not verify the accuracy of
Supplier data.
Subsystem MTBF Data Release Policy
VIDYO does not release MTBF data below the system level.
The reasons for this policy are:
VIDYO considers internally designed subsystem MTBF data to be confidential intellectual
property.
VIDYO obtains supplier subsystem MTBF data under NDA and is prohibited from sharing such
data outside of VIDYO.
MTBF Reliability
The MTBF prediction is calculated using component and subassembly random failure rates. The
calculation is based on the Telcordia SR-332 Issue 2, Method I, Case 3.
Product
Part Number
MTBF
HD-40B
DEV-RM-HD40-B-SA-0A
640 hours
HD-100D
DEV-RM-HD100-D9020-SA-0A & DEV-RM-
HD100-D-NTPM-SA-0A
75,400 hours
