Steps
1. Open the Control Plan
Navigate to Risks space → Control Plan - AEB Sensor Unit to access the control plan Risksheet.
Scroll to the characteristic row where you need to define measurement methods. The Control Plan uses a three-level hierarchy:
3. Add or Edit the Control Method Row
Click the ➕ icon next to the characteristic to add a new Control Method (Level 3) row, or click an existing control method row to edit.
4. Select the Measurement Type
In the Control Method column, choose from:
- Error-Proofing (poka-yoke) - Physical design prevents defects
- Automated Gauging - Measurement devices with auto-stop
- Variable Gauging - Measurement with tolerance checking
- Attribute Gauging - Go/No-Go checking
- SPC Charting - Statistical process control monitoring
- Visual Inspection - Operator visual verification
Your measurement method directly affects the PFMEA Detection rating:
- Error-proofing → Detection = 1 (Almost Certain)
- Automated gauging → Detection = 2-3
- Variable/attribute gauging → Detection = 4-5
- SPC charting → Detection = 6
- Visual inspection (double) → Detection = 7
- Visual inspection (single) → Detection = 8
Lower detection ratings reduce RPN and improve risk mitigation effectiveness. 5. Define the Measurement Equipment
In the Equipment/Gauge column, specify the measurement device:
- CMM (Coordinate Measuring Machine) for dimensional verification
- Digital calipers or micrometers for manual measurement
- Automated vision systems for automated inspection
- Torque wrenches for fastener verification
- Multimeters or oscilloscopes for electrical testing
All measurement equipment must be calibrated and traceable to standards. Document calibration intervals and procedures in your quality system. The Control Plan does not enforce calibration tracking—this is managed externally.
| Column | Purpose | Example |
|---|
| Target Value | Nominal specification | 25.0 mm |
| Tolerance | Allowable variation | ±0.05 mm |
| Characteristic | What to measure | Housing bore diameter |
7. Link to the Characteristic
The Control Method row automatically inherits the characteristic link from its parent (Level 2). Verify the Class column displays:
- SC badge (orange background) for Special Characteristics
- CC badge (red background) for Critical Characteristics
8. Document the Measurement Procedure
In the Control Description column, provide step-by-step measurement instructions:
1. Zero CMM at reference datum A
2. Measure bore diameter at 3 points (0°, 120°, 240°)
3. Record average value
4. Verify within 25.0 ±0.05 mm tolerance
9. Verify Configuration
You should now see:
- ✅ Measurement method selected with appropriate Detection rating
- ✅ Equipment/gauge specified
- ✅ Target value and tolerance displayed from characteristic link
- ✅ SC/CC classification badge visible (if applicable)
- ✅ Measurement procedure documented
Control Method Decision Matrix
| Characteristic Criticality | Measurement Method | Detection Rating | Typical Equipment |
|---|
| CC (Critical) | Error-Proofing or Automated Gauging | 1-3 | Fixture with sensors |
| SC (Special) | Variable Gauging or SPC | 4-6 | CMM, calipers, SPC chart |
| Standard | Attribute Gauging or Visual | 5-8 | Go/No-Go gauge, visual |
Start with available measurement methods (visual, manual gauging) in initial control plans. As manufacturing matures, upgrade to automated detection and error-proofing for critical characteristics to reduce Detection ratings and improve process capability.
See Also
