Checklist attribute (defined for failure effects) containing the possible severity classes that can be assigned to each effect. The checklist must be set to “mutually exclusive” and have values assigned to each class (with the most severe class having the highest value). By default, a Severity attribute is included in each model, representing the four severity classes from MIL-STD- 1629A: I - Catastrophic, II - Critical, III - Marginal & IV - Minor. When omitted, the model will use the following six severity classes: Loss of Life, Loss of Equipment, Loss of Mission, Loss of Operation, Degraded Performance & No Effect.
This Attribute when defined replaces the default Severities
eXpress default Severities
MIL-STD- 1629A Severities
This predefined Attribute may be added to existing Attributes using Manage Design Templates
Calculating the RPN Values using Special Severity Attributes
RPN Severity calculations can overide the normal calculated values by creating an attributes for failure effects called “SeverityRating”, “SeverityPctg” or “SeverityMap”. When one or more of these attributes are included as columns in an eXpress FMECA chart, the calculated RPN will use these values (rather that the automatic calculations) as the corresponding rating factor. RPN Definition:Risk Priority Number (RPN).
