Interpreting Type 1 MSA (Measurement Systems Analysis) Results

G

grantmate

#1
Hi Guys

I am a novice at MSA studies but i have been tasked with implementing them into our company, but anyway here goes.
I have been doing GR&R studies on our equipment and appraises but it's been taking longer than expected. So i thought a Type 1 study(less accurate but acceptable by customer) would be quicker.
The issue is, i have started with 2 - 3" Micrometer and got the exact same result 30 times measuring 1 part by 1 appraiser(obviously got 1000000% repeatability) and then tried introducing more parts (5) and measured them in sequence 6 times each(30 results) and got this result(see attached file). now the repeatability is barely acceptable but the capability presented is out.

any suggestions on how best to do a MSA study with only one appraiser to give a repeatability percentage (my current constraints from manager)

any advice would be appreciated

thanks

Grant
 

Attachments

Elsmar Forum Sponsor

Bev D

Heretical Statistician
Staff member
Super Moderator
#2
Re: Type 1 MSA Help intrepreting the results

OK I'm really sorry your boss thinks that someone who is untrained/uneducated in MSA can 'just do the job'. While they may be able to fulfill the cookbook stuff to make a Customer 'happy', they can't do anything else very well. this isn't 'easy' or intuitively obvious. you did the right thing by seeking out help from others who have experience and knowledge in this field.

first - you have to randomize the readings for every part when multipel parts are involved. there is a clear bias towards greater repeatability at teh end of the 6 readings (the resutls are much closer to each other)...if I read you correctly. and of course there is almost no part to part variation. This results in an overinflated SD that makes the Cg ratio look smaller than it really should be.

If you only have one operator and you are really only intereseted in repeatability then my suggestion is to use 30 parts each measured twice. Remember to randomize which parts are measured adn ensure that the second reading of any given part is not sequential to the first reading. ( operators have a human nature response to try to get the same resutls when they 'know' what they got the first time)

You can calculate the measurement error as the average range of the two readings for each of the 30 parts divided by 1.128.

then you can calculate the total observed SD directly.

see this MSA Spreadsheet for templates and references.
 

rickpaul01

Involved in HankyPanky
#3
Re: Type 1 MSA Help intrepreting the results

Hi Bev, The spreadsheet doesn't load correctly from here. Can you email it to me? Do you have my email address?
Thanks
 
G

grantmate

#5
thanks guys this really helped. will try some a few tests to see if i finally have a method nailed down.:applause:
 
Last edited by a moderator:
Thread starter Similar threads Forum Replies Date
Q Interpreting China Medical Device regulations/standards China Medical Device Regulations 1
P ISO 80369-7 standard - Interpreting which Parts should be in scope Other Medical Device Related Standards 7
K PACS - interpreting MDD and Borderline Guidance CE Marking (Conformité Européene) / CB Scheme 5
M List of Packaging Contents - Medical Devices - Interpreting EU Directive 93/42/EEC CE Marking (Conformité Européene) / CB Scheme 3
D Interpreting Normal vs Weibull Capabilities Capability, Accuracy and Stability - Processes, Machines, etc. 4
P Interpreting Span Measurement - P95-P5 Six Sigma 1
B Interpreting Deviations 5 & 6 in Annex ZA in ISO 14971:2012 ISO 14971 - Medical Device Risk Management 1
B Interpreting "misuse" when assessing Hazardous Situations ISO 14971 - Medical Device Risk Management 2
SteveK Interpreting clause 4.1.5 in ISO 13485:2016 ISO 13485:2016 - Medical Device Quality Management Systems 9
M Interpreting Process Controls - 21 CFR Part 820.70(a) 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 5
M Help interpreting 21 CFR Part 806 (corrections and removals) Other US Medical Device Regulations 1
M Help interpreting MIL-STD-105E Single Sampling Plans Tables Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
M Biocompatibility in Respiratory Products - Help interpreting whitepaper IEC 60601 - Medical Electrical Equipment Safety Standards Series 22
I Interpreting Product Realization (Clause 7) in ISO 9001:2008 for Service Industry ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 5
V GD&T Interpreting Datums in Two Single Segmented Position Tolerances Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
M Interpreting X bar and R Control Charts Statistical Analysis Tools, Techniques and SPC 2
B Help with interpreting stock market terminologies Coffee Break and Water Cooler Discussions 4
V Interpreting Zinc Plating Specification GMW 3044 - 6K96/48 APQP and PPAP 2
K Interpreting and Applying 7.3.2 Design and Development Inputs ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 4
S Interpreting the Calibration Report for my Dial Indicator General Measurement Device and Calibration Topics 3
J Interpreting Process Capability results and ratios Capability, Accuracy and Stability - Processes, Machines, etc. 1
B Length Measure - Interpreting Calibration Results and Measurement Uncertainty (MU) Measurement Uncertainty (MU) 3
S Interpreting Level of Confidence - Round Robin for Tensile Testing - Help needed Statistical Analysis Tools, Techniques and SPC 4
M Interpreting AS9100 Clause 8.2.2 Internal Audit Requirements Internal Auditing 28
T Interpreting my t test in Minitab Using Minitab Software 2
S Interpreting Linear Regression Results from Minitab Using Minitab Software 15
optomist1 Interpreting LMC for Pattern of Slots (GD&T) Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
optomist1 Interpreting Minitab Test For Equal Variances Using Minitab Software 3
V Interpreting Minitab Gauge R&R Results Using Minitab Software 6
A ISO 2081 - Interpreting Coating Thickness Other ISO and International Standards and European Regulations 3
L Interpreting Injection Molding Tooling Documents - Cavities Manufacturing and Related Processes 3
C Interpreting Gage R&R Results - 3 operators, 3 iterations and 10 parts Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
M Interpreting Measurement Uncertainty for Temperature PRT probes Measurement Uncertainty (MU) 2
N Interpreting Hygrometer Calibration Uncertainty - Temperature Coefficient Measurement Uncertainty (MU) 1
mr500 Interpreting Decimals in the mm state - Off Wall Question Inspection, Prints (Drawings), Testing, Sampling and Related Topics 14
J Interpreting clause 7.5.2.1 (validation of software used in production & service) ISO 13485:2016 - Medical Device Quality Management Systems 2
E Interpreting Partial Least Square Results Using Minitab Software 1
C Interpreting Outside Laboratory Calibration Certificate Measurement Uncertainty (MU) 3
M Interpreting MIL-PRF-19500 (Performance Spec, Semicon Dev) - What is LTPD of 20 - ??? Manufacturing and Related Processes 4
T Rules for interpreting control charts Statistical Analysis Tools, Techniques and SPC 2
Q Interpreting Responsibility and Authority Clause 5.5.1 ISO 13485 ISO 13485:2016 - Medical Device Quality Management Systems 18
H Interpreting 'Evaluation of compliance' in ISO 14001 Internal Auditing 4
P Micrometer Gage R&R study - Interpreting the data and suggestions Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
W Interpreting a Normal Probability Plot Statistical Analysis Tools, Techniques and SPC 4
Wes Bucey "Downsizing" ramifications - Evaluating and Interpreting the News World News 0
Q Interpreting calibration result of Air Particle Counter on Counting efficiency General Measurement Device and Calibration Topics 1
A Particle Counter Results - Interpreting Data for a Class 100,000 Cleanroom Other Medical Device Related Standards 12
M GD&T Q&A session - Interpreting FCF (Feature Control Frame) Inspection, Prints (Drawings), Testing, Sampling and Related Topics 43
N TL 9000 - Help Interpreting Normalization Unit for Measurements TL 9000 Telecommunications Standard and QuEST 2
K Question on Cp index - Calculating and Interpreting Cp and Cpl. Statistical Analysis Tools, Techniques and SPC 6

Similar threads

Top Bottom