Session 4.4: Failure Rate Prediction

Session 4.4 Outline

• 4.4.1: Failure Rate Prediction in Standards Context
• 4.4.2: Create a Failure Rate Prediction Analysis
• 4.4.3: Enter Part Detail Parameters
• 4.4.4: Apply Predicted MTTF to Item(s)

Discussion 4.4.1: Failure Rate Prediction in Standards Context

• MIL-HDBK-217F: Handbook for calculating reliability predictions using the Part Stress Analysis method
• Failure Rate Prediction purpose:
  • Establish & maintain consistent and uniform methods for estimating inherent reliability
  • Provide common basis of reliability prediction during acquisition stage
  • Standard applies to electronic equipment & systems
• Performed during Detailed Design Stages
• Applied to Component & Part-level Items

Exercise 4.4.2: Create a Failure Rate Prediction Analysis

1. Select Analyses > Failure Rate Prediction from the menu bar
2. Select the icon to create a new Failure Rate Analysis
3. Enter the following details:
   • Name: Training Analysis
   • Description: Example Failure Rate Prediction analysis for Control Unit.
   • Verify Failure Rate Standard type is 217F Notice 2 — Electronic Reliability Prediction
   • Select Create
4. In the Predicted Failure Rate section, select the item picker to choose a model item
5. Select Control Unit as the item for analysis
6. Select Next/OK
7. Select Add to add New Parts to the analysis
8. In the New Part dialog, search for PCB
9. Select Connectors, Card Edge, Printed Circuit Board (PCB) from the list
10. Select OK

Exercise 4.4.3: Enter Part Detail Parameters

Verify the following parameters:

• Part Quantity is 1
• Base Failure Rate: Card Edge, Printed Circuit Board (PCB)
• Environment Factor: GB — Ground, Benign
• Quality Factor: LOWER

Change the following parameters:

• Mating/Unmating Factor: > 50 Cycles/10³ Hours
• Connected Ambient Temperature: 40
• Amperes per Contact: 100, 32 Gauge

Exercise 4.4.4: Apply Predicted Failure Rate to Items

• Verify Predicted Failure Rate: 67.6858
• Select Apply
• Verify updated MTTF for Control Unit from the Properties viewer

Session 4.4 Summary

• 4.4.1: Failure Rate Prediction in Standards Context
• 4.4.2: Create a Failure Rate Prediction Analysis
• 4.4.3: Enter Part Detail Parameters
• 4.4.4: Apply Predicted MTTF to Item(s)