This is a PFMEA example for a made-up welded bracket, rated with Action Priority (AP) instead of RPN. Each row has severity, occurrence and detection, and the AP comes from the AIAG and VDA Action Priority table: high is the top priority for action, medium means act or justify, low means action is optional. The weld row started as a high and dropped to a low once the actions were in place.
The case: bracket 4410-B is a laser cut, press brake formed steel bracket with an M8 nut projection welded on. The customer bolts it into an assembly. Lot 2610-14, 1,200 pieces, shipped and then came back as a complaint: nuts spinning loose when the bolt was torqued. This PFMEA covers the bracket process after that complaint.
Process steps
10 Receive steel blanks. 20 Laser cut profile and holes. 30 Press brake bend. 40 Projection weld M8 nut. 50 Final inspect and pack.
The PFMEA, as found
| Step | Failure mode | Effect | S | Cause | Prevention | O | Detection | D | AP |
|---|---|---|---|---|---|---|---|---|---|
| 40 Weld nut | Weak weld | Nut spins at customer torque. Line stop, parts scrapped. | 8 | Electrode tip worn past limit | Tip dress once per shift | 5 | Push-out test, first piece of shift | 7 | H |
| 40 Weld nut | Nut missing | Bolt cannot be fitted. Line stop. | 7 | Nut not loaded | Work instruction, training | 4 | Nut presence sensor, interlocked | 2 | M |
| 30 Bend | Angle out of tolerance | Holes misalign at assembly. Bracket forced to fit. | 6 | Springback varies between coils | Setup sheet | 6 | Angle check, first piece and hourly | 6 | M |
| 20 Laser cut | Hole position off | Bracket will not mount. | 7 | Wrong program loaded | Program called by barcode on traveler | 2 | Check fixture, first piece | 4 | L |
| 50 Pack | Mixed revisions in a box | Wrong part at the customer. Line stop. | 7 | Old revision left at the cell at changeover | Line clearance checklist | 3 | Visual at pack | 7 | M |
Actions and re-rating
| Row | Action taken | New O | New D | New AP |
|---|---|---|---|---|
| Weak weld | Tip dress every 400 welds with controller interlock. Weld current monitoring with fault stop and reject on every weld. | 3 | 3 | L |
| Nut missing | No change. Presence sensor already stops the cell. Decision and reason recorded in the PFMEA. | 4 | 2 | M |
| Angle out of tolerance | Bend program per material thickness with springback compensation. | 4 | 6 | L |
| Hole position off | No action needed. | 2 | 4 | L |
| Mixed revisions | Pack station scans each label against the traveler revision. | 3 | 4 | L |
How to read the AP
- Severity comes first. AP is looked up from the three ratings together, with severity weighted first. It is not a product like RPN, so a 7, 4, 2 can still be medium while an 8, 3, 3 is low.
- High is the top priority. The handbook expects an action, or a written reason why the current controls are enough. The weld row was the only high, and it got the actions first.
- Medium means act or justify. The missing nut row stayed medium. The team kept it and wrote down why: a sensor already stops the cell, and occurrence is not driven by anything they can change cheaply.
- Re-rate after the action is proven, not when it is planned. The new ratings went in after the 8D effectiveness data came in.
AP values on this page were looked up in the AIAG and VDA PFMEA Action Priority table. Check them against your own copy of the handbook and your customer requirements. Ratings scales are your company's.
The controls in the right-hand columns carry straight into the Control Plan example. The weld row came out of the 8D report example.
Everything on this page is made up for the example: the part, the numbers, the customer and the team. Use your own forms, rating scales and customer requirements.
Use these next
- How to write a PFMEA, the method behind this example
- 8D report example
- 5 Why example
- Control Plan example
- Quality glossary, for any term on this page
- Free tool: PFMEA to Control Plan check
- On Etsy: the Process FMEA workbook, the same form ready to fill in