In-Process Production Test Stations in PFMEA (Process FMEA)

Elsmar Forum Sponsor

Cephissus

Involved In Discussions
#12
It is the case with us, all test items are always mentioned as Detection Actions.

We only add them also as Process Step when the test itself can physically harm/damage the product.
 

John Predmore

Quite Involved in Discussions
#13
The most common control for an inspection process [with a sensor] would be a calibration program. Others might include an R&R study, red rabbit testing, etc.
Thank you, Miner. Many people think of calibration strictly as an annual exercise and R&R as a one-time activity. I had not heard of the term red rabbit testing, but that means putting a known bad part into the process and making sure it's detected.

Taking that idea one step further, my company uses what we call "challenging" the automated test station. A green master part, typically spray painted Green, is created to pass every time, and a red master part is designed to fail every time. For a leak test station, for example, the green master was epoxied shut so it would never leak, and the red master, also epoxied shut but drilled with a single hole of precise diameter, provided a known, stable rate of leak to slightly exceed the leak specification limit. The red/green challenge test was done daily or at the beginning of every shift.

If the green master ever failed the leak test or the red master passed, the the test station was suspect, and manufacturing would halt while the engineers investigate. The advantage of using physical parts modified not to leak (as opposed to internal valves or disabling the vacuum source) was this tactic could discover random causes, such as a pinched tube in the equipment, a clogged filter restricting airflow, a damaged or dirty gasket, or a vacuum fitting which had loosened over time.

In the context of PFMEA, there are dozens of causes for a leak test to fail, too many to consider exhaustively, but the net consequence of failure is a good part might fail as a leak and a leaking part might pass as good. The challenge test I describe is a simple control method to improve the detection score on the FMEA, as an inexpensive way to reduce risk from a myriad of failure mechanisms.
 

nitros1

Starting to get Involved
#14
Guys, speaking of red rabbits for testing, some people say they should be classified in a PFMEA under the detection controls, and others like our OEM customer lead engineer that they should be listed under preventive controls columnm any thoughts? Also, how bad off limit should a bad part be made?

Thanks
 

Cephissus

Involved In Discussions
#15
I would not have thought to mention red rabbits in any of the two columns.

To me the red rabbits are used to verify that a detection system is working fine.

The testing of Red Rabbits, according to my understanding, is a form of Measurement System Analysis and doesn't belong to the PFMEA.

To answer the question: How bad off limit should the part be made? I think you would find your answers in the MSA handbook (from AIAG I think).

For continuous measurements like a height, it doesn't matter how off limit the NOK part, you just need to see if your machine is capable of measuring the real value (the acceptance/rejection is done later through Software controls).
 

dominique

Quality Manager
#16
R&R and Capability is good, but glitches happen fast when sensors are used to check 24/7 for product type features or design intent, I would consider Running Red rabbit checks on known system aspects on a scheduled and Layered frequency, dependent on the severity of the inspection station. Also PM frequencies of the complete unit. If severity is on a life and limb application I would also consider redundancy Power circuit checks; checking that the checks worked.
 
#18
It is the case with us, all test items are always mentioned as Detection Actions.

We only add them also as Process Step when the test itself can physically harm/damage the product.
During our latest IATF 16949 audit we were cited a NC for improper occurence ratings. The auditor used our leak test as an example. He witnessed three leak test failures in a row and said that we should have them represented on the pfmea. We have leal test items on the pfmea but only for failure mode caused by the leak tester. Can you cited the AIAG standard to support your comment above? It will really help us out.
 

AMIT BALLAL

Trusted Information Resource
#19
During our latest IATF 16949 audit we were cited a NC for improper occurence ratings. The auditor used our leak test as an example. He witnessed three leak test failures in a row and said that we should have them represented on the pfmea. We have leal test items on the pfmea but only for failure mode caused by the leak tester. Can you cited the AIAG standard to support your comment above? It will really help us out.
If I didn't understand your process incorrectly, "Failure mode caused by Leak tester" should come under detection- it being a monitoring/measuring equipment used to detect the failure mode. And if there are leakage failures occurring, occurrence rating should reflect the same. You can collect data of defects on a monthly basis (my suggestion, do what is best for your organization) to review whether defects are occurring in order to review occurrence rating.

The FMEA reference manual he might be citing is "AIAG FMEA 4th edition manual" since the AIAG-VDA FMEA is still under the process of implementation and might take some time in order to auditor to start auditing with reference to it. Still, better to check with the auditor which AIAG manual version he is referring to.
 
Thread starter Similar threads Forum Replies Date
Sidney Vianna AS9100 News PPAP in the Aerospace Sector - What is it? AS9145 - Requirements for Advanced Product Quality Planning and Production Part Approval Process AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 10
H Informational What is PPAP (Production Part Approval Process)? APQP and PPAP 22
K AS9100D production process scheduling requirements Internal Auditing 14
A Statistical Process Control and Inspection in Footwear Production Statistical Analysis Tools, Techniques and SPC 0
J Differences between a Risk Management Plan vs. Production Part Approval Process AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 3
K FAI (First Article Inspection) vs PPAP (Production Part Approval Process) APQP and PPAP 15
M Cement Production Process Audit Process Audits and Layered Process Audits 3
I Where to find VDA 6.3 Robust Production Process (rpp) PDF file ? VDA Standards - Germany's Automotive Standards 1
S Production Process Sheet Review Meetings ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
R Calibration of processing equipment - 21 CFR 820.70 Production and process controls 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 3
Q Form for Managing Coating Process Parameter Changes during Production Document Control Systems, Procedures, Forms and Templates 2
Q Introducing Process based approach on Production Floor Manufacturing and Related Processes 6
J PPAP (Production Part Approval Process) Requirements for Annual Revalidations APQP and PPAP 1
B Example of Production Process Change having Significant Consequences AS9100C 7.5.1.2 AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 0
V Production Development Process APQP Methodology APQP and PPAP 9
M Changes Assessment as per AS9100 Clause 7.5.1.2 Control of Production Process Changes AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 5
V Supplier?s PPAP - Production Process Control Plan Review, Evaluation and Approval? FMEA and Control Plans 5
G AS9100 Clause 7.5.1.1 Production Process Verification Requirements AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 7
T How to link Process Design Changes in Serial Production to Design & Development? Design and Development of Products and Processes 6
P Risk Assessment Production Process Milling for Implantable Joints EU Medical Device Regulations 2
B ISO 9001 Clause 7.5.2 - Validation of Process for Production and Service Provision ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 29
J Production Process Verification - AS9100 Clause 7.5.1.1 AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 9
J Production Process vs. Manufacturing Process - Differences IATF 16949 - Automotive Quality Systems Standard 2
P Production Process deviated from Documented Procedure ISO 13485:2016 - Medical Device Quality Management Systems 2
T Nylon Fiber Production - Job Interview - New to this type of process Manufacturing and Related Processes 1
R Suppliers Defects found during Production Process - Supplier Scorecards Quality Tools, Improvement and Analysis 6
B Complicated Production Process - Sub-Process Documentation Requirements ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 5
S Part Marking: When in the production process to mark parts? AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 9
S Validation of Production Process - Practical Example ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
Q Methods for doing Production Process Risk Analysis ISO 14971 - Medical Device Risk Management 4
A LPA's (Layered Process Audits) for Non-Production Support Processes Process Audits and Layered Process Audits 13
M Correlation Production Time Study on a Process on an Assembly Line Manufacturing and Related Processes 3
R Starting In-Process Quality Inspection in the Production Shopfloor Inspection, Prints (Drawings), Testing, Sampling and Related Topics 13
W Process of Pre-Production under Mass Production Conditions IATF 16949 - Automotive Quality Systems Standard 6
P Robots in a Production Line - Control Plan and Process FMEA Manufacturing and Related Processes 9
M PPAP (Production Part Approval Process) files for Ford APQP and PPAP 11
K Process Validation of Low Volume Production of Medical Devices ISO 13485:2016 - Medical Device Quality Management Systems 9
R Line Leader Assessment form - Qualification process for production line leader Training - Internal, External, Online and Distance Learning 1
A Production Process Planning - Medical Devices ISO 13485:2016 - Medical Device Quality Management Systems 4
S Quality Control during the Production Process (Space Constraints for QC Inspectors) Misc. Quality Assurance and Business Systems Related Topics 8
S Forms for changing process specifications during production Document Control Systems, Procedures, Forms and Templates 5
A Self-controlled production process - OK according to ISO 9001 requirements? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
A What is PPAP (Production Part Approval Process) Why submit it and/with PSW APQP and PPAP 2
B Help for beginner - PPAP (Production Part Approval Process) APQP and PPAP 9
S APQP Application - Product/process modification and production transfer APQP and PPAP 6
D Production Process in Ceramics - Toyota Production System Process Maps, Process Mapping and Turtle Diagrams 3
R Is Kappa Study Required during PPAP (Production Part Approval Process)? IATF 16949 - Automotive Quality Systems Standard 9
D "Special Production Process" Validation and TS16949 Clause 7.5.2.1 IATF 16949 - Automotive Quality Systems Standard 5
T Production Part Approval Process (PPAP) Presentation in ppt. format APQP and PPAP 3
M Audit of Goods In as part of the QSIT "Production & Process Controls" Schedule 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 4
Similar threads


















































Top Bottom