Open topic with navigation

About Degradation Mechanism Evaluations (DMEs)

For each Degradation Mechanism (DM) that belongs to an RBI Criticality Analysis, a corresponding Criticality Degradation Mech Evaluation record also belongs to that RBI Criticality Analysis. In each Criticality Degradation Mech Evaluation that is associated with a qualitative degradation mechanism (i.e., the corresponding RBI Degradation Mechanisms record was created from a Potential Degradation Mechanism with the value Qualitative in the Methodology Type field), you can specify the probability that the corresponding component will fail due to that degradation mechanism.

For example, if an RBI Criticality Analysis contains an ErosionDM, it will also contain a corresponding Erosion Criticality Degradation Mech Evaluation. In this DME, you can specify a value in the Probability Category field to indicate the probability that the RBI Component will fail due to erosion.

After you select a value in the Probability Category field and calculate the RBI Criticality Analysis, the Probability Category Description field will be populated automatically based on the values in an existing Degradation Mechanisms Evaluation Factors record.

Example: Degradation Mechanisms

Suppose a Degradation Mechanisms Evaluation Factors record contains the following values in the following fields:

• Degradation Mechanism: Erosion
• Ranking: 1
• Ranking Description: Erosion - Impact Resistant Material. Good Inspection History with no evidence of Damage.

If an RBI Analysis is linked to an Erosion Criticality Degradation Mech Evaluation, and you select 1 in the Probability Category field, the value in the Probability Category Description field will be populated with the value in the Ranking Description field in the Degradation Mechanisms Evaluation Factors record containing the values Erosion and 1. In this example, the Probability Category Description field would be populated with the value Erosion - Impact Resistant Material. Good Inspection History with no evidence of Damage.