Specifications

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Maintenance
Reliability
All specifications in this section assume that the SX-2000 system is operating within its specified
environmental limits. No reliability performance can be defined outside those limits. Some
degradation of the quoted failure rates can be expected when a system operates at the extremes
of the
environmental specification, page 73. MILITARY HANDBOOK 217D has been used for
failure rate calculations. Degradation from the nominal failure rates is approximately double
the calculated failure rate for every 18ºF (10ºC) rise above the external room ambient of 68ºF
(20ºC).
Early life effect is defined as the first six months after installation, where hardware reliability
performance is affected by the component’s infant mortality and production quality defects.
After the early life period, the average number of maintenance actions do not exceed 0.200
per 100 stations per month. Early life effects are determined in terms of hardware early life
effect and system early life effect.
• Hardware: The early life effect for hardware failure is less than twice the useful life failure
rate averaged over the first six months of operation. This is equivalent to 0.40 failures/100
stations/month. This does not include Dead On Arrivals or No Faults Found.
• System: The system outages or downtimes are also affected during the early life period.
This affects all newly installed systems and is greater than three times that specified as
the nominal. This is averaged over the first six months after installation, and does not
exceed 0.90 failures/100 stations/month.
Program Load Times: The time required to reload the subsystems of the SX-2000 system
does not exceed 10 minutes. The time required from attendant console power-on to being able
to process simple calls is less than 5 minutes, not including cold system start-up time.
Maintenance and Service
General
• Service documentation is structured so that personnel with varying levels of experience
or technical knowledge can easily locate and understand the desired information. The
documentation is targeted at technically qualified service personnel.
• All system-detected errors (both software and hardware) are automatically entered in an
Error Log which is maintained in non-volatile storage. All pertinent information necessary
to uniquely identify the elements associated with the error is logged in the file or pointers
are provided to identify its location in storage.
• Maintenance activity can be performed concurrently, with no perceived impact on user
operations, except for those resources required to correct the malfunction.