Failure Mode and Effect Analysis for a Programmable Logic Controller-Based Control Unit for a Miniature Neutron Source Reactor Pneumatic Transfer System
Table 1
Severity classification and description used in FMEA.
Effect
System functionality
Rating
Catastrophic
Totally incapacitates the system and fails to satisfy the design intent
10
Critical
Significantly reduces the effectiveness of the system such that it would have little or no benefit and fails to satisfy the design intent
9
8
High
Significantly reduces the effectiveness of the system such that it would fail to satisfy the design intent. However, the system would still operate and significant benefit would be gained from its operation
7
6
Medium
Reduces the level of redundancy that is built into the system. The effectiveness of the system would not be significantly reduced, and the design intent would still be satisfied
5
4
Low
Reduces the effectiveness of the system such that it is outside normal operating limits. However, the design intent would still be satisfied