Title:
Engineering Specification: 12.1-inch AMLCD Monitor
Page
23 of 27
Document Number
: 023-0284-00
Revision:
A
9.0
RELIABILITY
9.1 Design Workload
The Monitor is capable of operating 24 hours a day, 365 days a year under the specified environmental
conditions per section 3.1.
9.2 Critical Failures
Critical failures is defined as failures that render the Monitor inoperable to the end user. The MTBCF
(Mean Time Between Critical Failures) value excludes the fluorescent backlight assembly which
requires periodic replacement and assumes periodic cleaning of air filtration screens to ensure
adequate air flow for cooling.
The Monitor MTBCF is > 40,000 hours.
Note: MTBCF excludes fluorescent tubes from calculation. Calculation is made per MIL Reliability
Handbook 217 Method 3.
9.3 Failure Definition
In general, the term failure denotes a fully functional Monitor unit ceasing to function within its
required performance capability because of conditions internal to the Monitor unit. The requirements
of Section refer to critical failures, defined and distinguished from others as follows:
Monitor Failure
- Monitor ceases full operation. The failure cannot be corrected without at least one
of the following: tools, test equipment, replacement parts, checks of the Monitor unit, and knowledge
beyond performing routine operations.
Nuisance Failure
- A component in the Monitor unit has ceased operation but does not impair the
required operation of the unit.
Not Machine Failures
- Malfunctions attributable to the following causes shall not be classified as
failures:
•
Improper installation or maintenance
•
Abuse or misuse
•
Exposure to environments outside the specified design range.
•
Lack of prescribed preventative maintenance.
•
Failures caused by test equipment used to control cycle and check the operation of Display units
on test.
