What are the general rules / guidelines when doing a machine capability study?

M

maxschnau

#1
WHat are the general rules / guidelines when doing say a 30 pc measurement capability study on a dimension on a part. Say one part is out of spec, can you get another part?, can you refixture the part?, etc, and if you have the anser to these rules, what source do they come from?

THANKS!!!
 
Elsmar Forum Sponsor

Jim Wynne

Leader
Admin
#2
maxschnau said:
WHat are the general rules / guidelines when doing say a 30 pc measurement capability study on a dimension on a part. Say one part is out of spec, can you get another part?, can you refixture the part?, etc, and if you have the anser to these rules, what source do they come from?

THANKS!!!
Please explain what you mean by "capability study." What information are you hoping to get from the study?
 
M

maxschnau

#3
I mean capability study - Initial Capability Studay as is required by Automotive. I would be looking to achieve a 1.33 or above CPK.
 

Jim Wynne

Leader
Admin
#4
maxschnau said:
I mean capability study - Initial Capability Studay as is required by Automotive. I would be looking to achieve a 1.33 or above CPK.
You can't do that (by default) with just 30 pieces. Here are the default requirements as stated in the AIAG PPAP manual (3rd Edition):
For those characteristics that can be studied using X-bar and R charts, a short term study should be based on a minimum of 25 subgroups containing at least 100 readings from consecutive parts of the significant production run...
Furthermore, you can't calculate Cpk without first verifying that the process is in a state of statistical control, and I don't know how you can do that with a 30-piece sample.
 
M

maxschnau

#5
OK, Let's say it's a 300 Piece Study. What are the rules of remeasuring or refixturing or replacing a part that is considered a flyer by the data.........
 
R

ralphsulser

#6
Plus, when you find something in your sample size out of spec. you can't throw it out and ignore it, or change the gauge either :rolleyes:
 
M

maxschnau

#7
OK, Let's say it's a 300 Piece Study. What are the rules of remeasuring or refixturing or replacing a part that is considered a flyer by the data.........
 

Miner

Forum Moderator
Leader
Admin
#8
maxschnau said:
OK, Let's say it's a 300 Piece Study. What are the rules of remeasuring or refixturing or replacing a part that is considered a flyer by the data.........
You cannot ignore a part that is flyer unless there is a legitimate reason. By your questions about refixturing, it appears that you suspect that the part was incorrectly loaded into a measurement fixture, or there was debris between the part and fixture that threw the reading out. In a case such as these, you could legitimately clean the fixture, remeasure the same part and substitute the results.

However, in another example, this would not be true. Let's say that during the manufacture of product, a change occurred (material lot, etc.), the process shifted, then was adjusted back. In this example, the "flyer" is a legitimate part of the data that is telling you that the process is not always in control. You cannot simply throw this data out. You have to bring the process into control and re-study.
 
Thread starter Similar threads Forum Replies Date
Jim Wynne Informational Control Chart Interpretation - General "Rules" Statistical Analysis Tools, Techniques and SPC 92
A Difference between general PMCF and PMS EU Medical Device Regulations 0
Dan Pare Density Column setup for Measuring General Purpose ABS General Measurement Device and Calibration Topics 0
Watchcat REGULATORY WATCHCAT - De Novo Proposed Rule - General Comments Other US Medical Device Regulations 2
E Technical documentation for IVDD General/ other CE Marking (Conformité Européene) / CB Scheme 3
C Certification vs Accreditation Training (General) Training - Internal, External, Online and Distance Learning 1
Judy Abbott General temperature used in the blasting process and laser process Manufacturing and Related Processes 2
D Preventive Maintenance vs. General Cleaning ISO 13485:2016 - Medical Device Quality Management Systems 2
Y What are different Special Inspection Level 1-4 and General spesification 1-3 ? AQL - Acceptable Quality Level 0
B General Motors and Honda Alliance - What does this mean to suppliers? IATF 16949 - Automotive Quality Systems Standard 3
F General Data Protection Regulation (GDRP) CE Marking (Conformité Européene) / CB Scheme 6
A Interpretation of GMP Requirements for class 1 medical device manufacturer (device GMP exempt, only General controls applicable) 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 4
D Importing a general wellness low risk product Other US Medical Device Regulations 3
M ISO 13485 for general purpose disinfectants? ISO 13485:2016 - Medical Device Quality Management Systems 9
M Do you need an Applicable general safety and performance requirements Checklist? EU Medical Device Regulations 2
DitchDigger UDI, Labeling Accessories, General Insanity, Etc. US Food and Drug Administration (FDA) 1
G Problem Resolution Report Monitoring - Customer complaint or PRR as general motors use Customer Complaints 12
P Is there a counterpart to the General Safety and Performance Regulations for the USA? Other US Medical Device Regulations 4
C CE marking for general IVD (self-certified) & ISO 13485 QMS requirements - auditing EU Medical Device Regulations 6
M Informational WHO – Report by the Director-General – Standardization of medical devices nomenclature Medical Device and FDA Regulations and Standards News 0
J General Motors SSE Launch Algorithm - SCMS's Service Industry Specific Topics 0
D Incoming (Receiving) Inspection - General form for incoming part inspection Document Control Systems, Procedures, Forms and Templates 17
M Informational 2019 Meeting Materials of the General and Plastic Surgery Devices Panel Medical Device and FDA Regulations and Standards News 0
M FDA Guidance - general wellness products - wearables Other Medical Device Related Standards 5
MrTetris GDPR - General Data Protection Regulation - Only applicable to EU data? Other ISO and International Standards and European Regulations 6
M Informational The USFDA Announces General and Plastic Surgery Devices Panel of the Medical Devices Advisory Committee Meeting on March 25-26, 2019 Medical Device and FDA Regulations and Standards News 0
M Oxygen enriched environment applicability - Operating table used in general surgeries in hospital IEC 60601 - Medical Electrical Equipment Safety Standards Series 0
Marc Definition GSPR - General Safety and Performance Requirements Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 0
M Annex I - General Safety and Performance Requirements. Precise identity - how provided EU Medical Device Regulations 6
E What is the general time line to prepare for IATF Letter of Conformance? IATF 16949 - Automotive Quality Systems Standard 1
S General Awareness Training for AS9100 Rev.D AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 8
B IVD or a general product test kit (if such a thing exists) EU Medical Device Regulations 0
L GDPR scope - "Personal data" definition - General Data Protection Regulation EU Medical Device Regulations 5
S GDPR (General Data Protection Regulation) - My company is ISMS certified IEC 27001 - Information Security Management Systems (ISMS) 5
S Business development and support - Getting business general liability insurance Career and Occupation Discussions 5
DietCokeofEvil What is the general consensus on Caliper tolerances? General Measurement Device and Calibration Topics 1
W EU GDPR General Data Protection Regulation - What we need to update for our QMS EU Medical Device Regulations 14
Y Change Control - General Processes ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 1
D General questions about Medical Device MOPs and MOPPs IEC 60601 - Medical Electrical Equipment Safety Standards Series 31
Albert G. What are general examples of audit findings with ISO 9001:2015? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 15
H ISO 9001:2015 Cl. 9.3.1 - General Director doesn't participate in Management Review ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 8
T GDPR - General Data Protection Regulation (EU and UK 2018) Other ISO and International Standards and European Regulations 7
S AS9100D Transitional Audit General Question Checklist AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 5
S Dates on Labels acceptable to the USA - GS1 General Specification 3.4.4 Other US Medical Device Regulations 3
K Thoughts on the impact of the General Data Protection Regulation? Medical Information Technology, Medical Software and Health Informatics 5
Pmarszal Clarification for 21 CFR Part 11.100 - General Requirements Other US Medical Device Regulations 14
T Difference betwee General vs. Follow-up Inspections US Food and Drug Administration (FDA) 3
L Wrist Actigraph Device - IEC 60601-1 general questions IEC 60601 - Medical Electrical Equipment Safety Standards Series 1
C When is a device considered "sold to the general public?" Canada Medical Device Regulations 2
C Iran - Who is holder of an Iranian registration in general? Other Medical Device Regulations World-Wide 2

Similar threads

Top Bottom