MSA With Minitab
MSA With Minitab
Ing. Ricardo Espinosa Álvarez, CQE, CSQP, CRE, CSSBB, CMQ / OE, CPIM, CSCP
ASQ Certified Black Belt
Certified Specialist in Core Tools by AIAG
ISO9001: 2015 Certified Lead Auditor by Exemplar Global
Certified Auditor of Suppliers IATF 16949: 2016 by AIAG
VDA 6.3 Certified Auditor
Email: ricardo_espinosa@kaizensigma.com
www.kaizensigma.com
LinkedIn: Ricardo Espinosa Alvarez
Contents
MSA concept
• The evaluation of measurement systems consists of determining the capacity and stability of
measurement systems through studies of:
• Stability
• Accuracy
• Linearity
• Repeatability
• Reproducibility
• The most commonly used statistical properties to characterize the quality of the information are the
bias (bias) and the variance of the measurement system.
• Bias refers to the location of the data in relation to the reference value.
• Variance refers to the spread of the data.
Bias
Average readings
(Accuracy)
Value of
reference
Variance (Precision)
Reference: AIAG Measurement Systems Analysis Fourth Edition June, 2010
© Copyright by Kaizen Sigma. 5
x xxx
xx xx x
Precise x xxx
xx xx x
x
x x
Not precise x x
x x x x x
x
x x x
x x
x x
© Copyright by Kaizen Sigma. 6
Bias X X X X
Accuracy
Stability X
(Bias)
Linearity X X
MSA
Resolution X X
Repeatability X X X
Precision
(Variance)
Reproducibility X
uncertainty X
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
Calibration
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
Importance of calibration
• To estimate the uncertainty of measurement, you must first identify the sources of the uncertainties.
Then estimate the influence of each of these sources of uncertainty.
• All sources of uncertainty are combined to obtain the combined uncertainty and multiplied by the
coverage factor (usually k = 2) associated with a confidence level (95%).
• Regardless of the sources of uncertainty, there are two ways to estimate uncertainty:
• Type B: obtained from other information such as calibration certificates, manufacturer's specifications,
calculations, publications.
𝑢 = 𝑢 +𝑢
Combined
Type A Type B
Random errors Systematic errors
𝑈 Δ𝑎 Δ𝑎
𝑢 = 𝑢 = 𝑢 =
The us is statistically evaluated 𝑘 12 24
𝑠
∑ 𝑥 −𝑥 𝑢 =
𝑠 =
𝑛−1
𝑛
MSA Summary
MSA Study Matrix
GR&R Range GR&R ANOVA GR&R ANOVA MSA Attributes
Calibration Resolution Stability Accuracy Study Type 1 Linearity
method Crossed Nested (Concordance)
3 operators 1
1 operator 1 3 operators 1
Tolerance / 1 operator 1 1 operator 1 1 operator 1 instrument 10 pieces
instrument 1 2 operators 1 instrument 15 pairs
resolution ≥10 instrument 1 instrument 1 instrument 5 covering the 3 operators 50 pieces
Recommended Uncertainty pattern 5 times instrument 5 pieces of parts spanning
and Process standard standard measured standards tolerance of the measured 3 times 25 OK and
method calculation per shift for 4 measured once per product tolerance, 5
variation / measured 10 50 times (Minitab measured 12 product, measured 3 25 NOT OK (Example AIAG)
w eeks (100 operator pairs measured by
resolution ≥10 times Example) times each times by each
readings) each operator
operator
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
Lower resolution
Resolution = 1
Higher resolution
Resolution = 0.1
Tolerance =
USL-LSL
Nominal
LSL USL
Lower Upper
specification limit specification
limit
Empirical Rule 10 to 1
Tolerancia
The smallest unit of the
instrument should divide the
tolerance or variation of the
process into 10 or more
parts (whichever is less)
6σ
LIE LSE ≥ 10
6σ Resolution
Tolerancia
Product tolerance
≥ 10
Resolution
LIE LSE
6σ
Reference: AIAG Measurement Systems Analysis Fourth Edition June, 2010
© Copyright by Kaizen Sigma. 22
Specification: 150±100 mm
USL= 250 mm
LSL= 50 mm
Tolerance= 200 mm
Std dev= 14.73 mm
Resolution: 1 mm
1 132
2 156
3 124
4 147
5 137
6 161
7 141
8 167
9 142
10 166
Inadequate resolution
• Another good indication of poor resolution is on a normal probability plot, where the data is stacked in
groups rather than flowing along the 45-degree line.
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
Stability study
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
• The measurement system must be in statistical control. Under repeatable conditions, variation in the
measurement system is due only to common causes and not special causes. This is known as statistical
stability and is evaluated by graphical methods.
Common causes
• Factors that cause variation that affects only a part of the result of the process.
• They are intermittent and unpredictable
• Special causes are identified by one or more points outside the control limits or non-random patterns
of points within the control limits.
• The process is not stable
• They can be harmful (remove) or beneficial (make permanent)
? ?
Process Stability
Longitud de perno
U C L=3.4728
3.46
Sample M ean
3.44
_
_
3.42 X=3.4227
3.40
3.38
LC L=3.3726
1 3 5 7 9 11 13 15 17 19 21 23 25
Sample
0.20
U C L=0.1838
0.15
Sample Range
0.10 _
R=0.0869
0.05
0.00 LC L=0
1 3 5 7 9 11 13 15 17 19 21 23 25
Sample
Type of
measurement
Continuous
Attribute
variable
Rule 1
Any point outside of limit controls
10.00
9.00 LCS
8.00
Average
7.00
LC
6.00
5.00 LCI
4.00
1 3 5 7 9 11 13 15 17 19 21 23 25
Sample
Rule 1
Any point outside of limit controls
1.6
1.4
1.2
LCS
1
Range
0.8
0.6
0.4
R
0.2
0
LCI
1 3 5 7 9 11 13 15 17 19 21 23 25
Sample
• Obtain a production part in the middle range of the measurements as a standard sample for stability
analysis.
• Measure the standard sample 3-5 times on a periodic basis (daily, weekly) at different times.
• Plot the information on an Average-Range control chart
• Establish control limits and evaluate unstable or out-of-control conditions using standard control chart
analysis
1 operator
1 instrument
1 piece measured multiple
times in a period of time
Reference: AIAG Measurement Systems Analysis Fourth Edition June, 2010
© Copyright by Kaizen Sigma. 36
days, four times a day and five times each 0.251 0.249 0.253 0.247 0.248
3
4 0.252 0.249 0.247 0.249 0.25
time. Evaluate the stability of the measurement 3 1
2
0.251
0.248
0.249
0.255
0.25
0.25
0.251
0.252
0.25
0.252
system 3 0.25 0.25 0.253 0.249 0.248
4 0.251 0.25 0.247 0.249 0.25
4 1 0.249 0.252 0.249 0.25 0.251
2 0.252 0.247 0.25 0.248 0.251
3 0.252 0.25 0.252 0.248 0.253
4 0.248 0.25 0.251 0.254 0.25
5 1 0.25 0.25 0.252 0.249 0.248
2 0.251 0.248 0.247 0.247 0.248
3 0.249 0.246 0.25 0.248 0.252
4 0.249 0.249 0.253 0.251 0.25
Stability.xls
© Copyright by Kaizen Sigma. 38
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
Accuracy study
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
Accuracy study
1 operator
Bias
1 instrument
1 reference
standard measured
multiple times
Accuracy study
Diameter 1 operator
LSL= 50.000 mm
USL= 250.000 mm
1 instrument
Tolerance= 200.000 mm
Reference= 118.000
1 reference standard
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
Type 1 Study
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
Type I Study
• Use Type I Study to assess the capability of a measurement process. This study assesses the combined
effects of bias and repeatability based on multiple measurements of the same part.
• A Type 1 Study should be performed prior to other repeatability and reproducibility studies.
• Type 1 Study
• Measure the standard in the analyzed measurement system, 25-50 consecutive times, removing and
placing the standard.
• Measure the standard 10 times on an alternate measurement system (Micrometer, CMM, etc.) and
obtain the average. This is the reference value in Minitab analysis.
• Analyze in Minitab
• Analyze and eliminate the sources of variation in the measurement system.
Type I Study
• Example: An electrode manufacturer wants to Diameter
evaluate the measurement system that
12.3057
measures the outer diameter of electrode
shafts to determine if the system accurately 12.3009
measures the shaft within the tolerance of 0.05 12.3037
mm. 12.2975
• An operator measures a reference shaft with a 12.3056
known outside diameter of 12.305 mm 50 12.3033
times. 12.3030
12.2965
12,2986
12.3031
12,3051
12.3056
12.3036
12,3091
12.3029
Type I Study
K 0.20
%Var(Repe𝑎𝑡𝑎𝑏𝑖𝑙𝑖𝑡𝑦) = 𝑥100 = 𝑥100 = 43.57%
C 0.46
K 0.20
%Var(Repeteatability 𝑎𝑛𝑑 𝐵𝑖𝑎𝑠) = 𝑥100 = 𝑥100 = 81.10%
Cgk 0.25
MSA Summary
MSA Study Matrix
GR&R Range GR&R ANOVA GR&R ANOVA MSA Attributes
Calibration Resolution Stability Accuracy Study Type 1 Linearity
method Crossed Nested (Concordance)
3 operators 1
1 operator 1 3 operators 1
Tolerance / 1 operator 1 1 operator 1 1 operator 1 instrument 10 pieces
instrument 1 2 operators 1 instrument 15 pairs
resolution ≥10 instrument 1 instrument 1 instrument 5 covering the 3 operators 50 pieces
Recommended Uncertainty pattern 5 times instrument 5 pieces of parts spanning
and Process standard standard measured standards tolerance of the measured 3 times 25 OK and
method calculation per shift for 4 measured once per product tolerance, 5
variation / measured 10 50 times (Minitab measured 12 product, measured 3 25 NOT OK (Example AIAG)
w eeks (100 operator pairs measured by
resolution ≥10 times Example) times each times by each
readings) each operator
operator
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
• Linearity is defined as the difference in accuracy (bias) between the master and the observed average
over the entire operating range of the instrument.
1 operator
Bias 2
1 instrument
Bias 1
Various parts covering
the range of the
instrument
Multiple measurements
of the same part
VR Lower part Top of the 1 pattern reading
of the range range
Linearity
Linearity
• Graph the line “bias = 0” and review the graph for indications of special causes and acceptance of
linearity.
• For the linearity of the system to be acceptable, the line "bias = 0" must be completely within the
confidence interval.
If p˃0.05
Acceptable
linearity
Hypothesis
testing for
accuracy:
Ho: Bias= 0
Ha: Bias ≠ 0
If p˃0.05
Acceptable
bias
Linearity
• Example: An operator measured the thickness of five pieces, 12 times each, with the instrument to be
tested, and once with the standard (master instrument). The parts were selected in such a way as to
cover the operating range of the instrument (measuring instrument). The specification of the part is
0.6 to 1 mm. The information is shown in the following table. Determine the linearity and accuracy of
the instrument
Reading Reading Reading Reading Reading Reading Reading Reading Reading Reading Reading Reading
P a rt Reference 1 2 3 4 5 6 7 8 9 10 11 12
P1 0.60 0.593 0.624 0.632 0.590 0.580 0.610 0.603 0.595 0.600 0.602 0.598 0.608
P2 0.70 0.681 0.711 0.720 0.694 0.700 0.691 0.710 0.723 0.691 0.700 0.700 0.704
P3 0.80 0.795 0.810 0.791 0.814 0.800 0.788 0.798 0.796 0.800 0.810 0.798 0.802
P4 0.90 0.933 0.940 0.910 0.880 0.892 0.887 0.913 0.891 0.874 0.882 0.905 0.895
P5 1.00 0.992 0.990 0.990 0.980 1.000 1.000 1.014 1.022 1.010 0.990 1.010 0.988
MSA.xls data
Linearity
If p˃0.05
Acceptable
linearity
Hypothesis
testing for
accuracy:
Ho: Bias= 0
Ha: Bias ≠ 0
If p˃0.05
Acceptable
bias
MSA Summary
MSA Study Matrix
GR&R Range GR&R ANOVA GR&R ANOVA MSA Attributes
Calibration Resolution Stability Accuracy Study Type 1 Linearity
method Crossed Nested (Concordance)
3 operators 1
1 operator 1 3 operators 1
Tolerance / 1 operator 1 1 operator 1 1 operator 1 instrument 10 pieces
instrument 1 2 operators 1 instrument 15 pairs
resolution ≥10 instrument 1 instrument 1 instrument 5 covering the 3 operators 50 pieces
Recommended Uncertainty pattern 5 times instrument 5 pieces of parts spanning
and Process standard standard measured standards tolerance of the measured 3 times 25 OK and
method calculation per shift for 4 measured once per product tolerance, 5
variation / measured 10 50 times (Minitab measured 12 product, measured 3 25 NOT OK (Example AIAG)
w eeks (100 operator pairs measured by
resolution ≥10 times Example) times each times by each
readings) each operator
operator
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
• For product control, the variability of the measurement system should be small compared to the
specification limits. Evaluate the measurement system against the tolerance of the characteristic.
6𝜎 &
• %𝐺𝑅𝑅
For process control, the = of the measurement
variability 𝑥100 system must demonstrate effective resolution
𝑇𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒
and be small compared to the variation of the manufacturing process. Evaluate the measurement
system against the 6 sigmas of process variation and / or the total variation of the MSA study.
𝜎 &
%𝐺𝑅𝑅 = 𝑥100
𝜎
• Repeatability
• Variation in measurements obtained with a measuring instrument when used multiple times by an
operator when measuring the identical characteristic in the same part
• Reproducibility
• Variation in the average of measurements made by different operators using the same instrument
when measuring a characteristic in a part
• GRR or Gage R&R
• Instrument repeatability and reproducibility: the combined estimation of repeatability and
reproducibility of the measurement system.
Repeatability
• Repeatability or precision is the variation in measurements made by a single operator on the same part
and with the same measuring instrument.
VR 1 operator
1 instrument
1 piece measured
several times
Repeatability
𝜎 & 6𝜎 &
%𝐺𝑅𝑅 = 𝑥100 %𝐺𝑅𝑅 = 𝑥100
𝜎 𝑇𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑖𝑎
𝜎
N𝑑𝑐 = 1.41
𝜎 &
• It is the number of divisions that the measurement system can measure through process variation.
• Indicates how well the process variation (runs and improvements) can be detected.
• There must be 5 or more different categories for the measurement system to be acceptable.
1 Data Category
3
Categori
es
10
Categories
• Acceptable methods:
• Range method
• Average and Range method (including control chart method)
• ANOVA method
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA method
(Crossed)
Range method
∑𝑅
A𝑣𝑒𝑟𝑎𝑔𝑒 R =
𝑛
𝑅
𝐺𝑅𝑅 =
𝑑∗
𝐺𝑅𝑅
%𝐺𝑅𝑅 = 100 ∗
𝑃𝑟𝑜𝑐𝑒𝑠𝑠 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑑𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛
MSA Summary
MSA Study Matrix
GR&R Range GR&R ANOVA GR&R ANOVA MSA Attributes
Calibration Resolution Stability Accuracy Study Type 1 Linearity
method Crossed Nested (Concordance)
3 operators 1
1 operator 1 3 operators 1
Tolerance / 1 operator 1 1 operator 1 1 operator 1 instrument 10 pieces
instrument 1 2 operators 1 instrument 15 pairs
resolution ≥10 instrument 1 instrument 1 instrument 5 covering the 3 operators 50 pieces
Recommended Uncertainty pattern 5 times instrument 5 pieces of parts spanning
and Process standard standard measured standards tolerance of the measured 3 times 25 OK and
method calculation per shift for 4 measured once per product tolerance, 5
variation / measured 10 50 times (Minitab measured 12 product, measured 3 25 NOT OK (Example AIAG)
w eeks (100 operator pairs measured by
resolution ≥10 times Example) times each times by each
readings) each operator
operator
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
Calibration
Resolution
Stability
Accuracy
Type 1
Linearity
GR&R
Range method
GR&R
ANOVA
(Crossed)
method
• Study method.
• Obtain a sample of n≥10 parts that represent the current or expected range of the process variation.
• Refer the operators as A, B, C, etc. and number the parts from 1 to n in such a way that the numbers
are not visible to operators.
• Calibrate the instrument if this is part of the normal measurement system procedure. Have the
operator A measure n parts in random order and record the results on row 1.
• Make operators B and C measure the same n parts without seeing each other's readings. Enter the
results on lines 6 and 11, respectively.
• Example: It is desired to carry out a repeatability and reproducibility study, for which 3 operators and a
calibrator were selected to measure the thickness of certain seals, whose specification is 3 to 5 mm.
These seals were measured three times by each operator. See data table.
•
MSA
Data>Stack>Columns
𝜎 & =𝜎 +𝜎
𝜎 =𝜎 +𝜎 ∗
𝜎 &
%𝐺𝑅𝑅 = 𝑥100
𝜎
6𝜎 &
%𝐺𝑅𝑅 = 𝑥100
𝑇𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒
<10=Acceptable
10-30=Marginal
>30=Non aceptable
ndc = 1.41
𝜎
Ndc shall be 5 or more
𝜎
92
&
© Copyright by Kaizen Sigma.
4.0
50
3.6
0 1 10 2 3 4 5 6 7 8 9
There should be no Gage R&R Repeat Reprod Part-to-Part
Pieza
out-of-control points R Chart by Operador
A B C Valor by Operador
UCL=0.1051
Sample Range
0.10 4.4
0.05 _
R=0.0408 4.0
0.00 LCL=0
3.6
1 1 0 2 3 4 5 6 7 8 9 1 10 2 3 4 5 6 7 8 9 1 1 0 2 3 4 5 6 7 8 9
Pieza A B C
More than Operador
50% of Xbar Chart by Operador
A B C
Pieza * Operador Interaction
points must 4.4
Sample Mean
UCL=3.966 4.4
be outside 4.0
__
X=3.924
Operador
A
the limits of B
Average
4.0 C
3.6 LCL=3.883
control
1 1 0 2 3 4 5 6 7 8 9 1 10 2 3 4 5 6 7 8 9 1 1 0 2 3 4 5 6 7 8 9 3.6
Pieza 1 10 2 3 4 5 6 7 8 9
Pieza
MSA Summary
MSA Study Matrix
GR&R Range GR&R ANOVA GR&R ANOVA MSA Attributes
Calibration Resolution Stability Accuracy Study Type 1 Linearity
method Crossed Nested (Concordance)
3 operators 1
1 operator 1 3 operators 1
Tolerance / 1 operator 1 1 operator 1 1 operator 1 instrument 10 pieces
instrument 1 2 operators 1 instrument 15 pairs
resolution ≥10 instrument 1 instrument 1 instrument 5 covering the 3 operators 50 pieces
Recommended Uncertainty pattern 5 times instrument 5 pieces of parts spanning
and Process standard standard measured standards tolerance of the measured 3 times 25 OK and
method calculation per shift for 4 measured once per product tolerance, 5
variation / measured 10 50 times (Minitab measured 12 product, measured 3 25 NOT OK (Example AIAG)
w eeks (100 operator pairs measured by
resolution ≥10 times Example) times each times by each
readings) each operator
operator
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
• Study methodology:
• 3 Operators are selected
• It is done with a measuring instrument
• 15 pairs of pieces are taken and assigned to each operator (5 pairs to
each). Each pair is made of consecutive pieces.
• See the following scheme:
Thursday
Par 5 Pair 10 Par 15
Friday
Destructiva.xls
© Copyright by Kaizen Sigma. 99
𝜎 &
%𝐺𝑅𝑅 = 𝑥100
𝜎
6𝜎 &
%𝐺𝑅𝑅 = 𝑥100
𝑇𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒
<10=Acceptable
10-30=Marginal
>30=Non aceptable
MSA Summary
MSA Study Matrix
GR&R Range GR&R ANOVA GR&R ANOVA MSA Attributes
Calibration Resolution Stability Accuracy Study Type 1 Linearity
method Crossed Nested (Concordance)
3 operators 1
1 operator 1 3 operators 1
Tolerance / 1 operator 1 1 operator 1 1 operator 1 instrument 10 pieces
instrument 1 2 operators 1 instrument 15 pairs
resolution ≥10 instrument 1 instrument 1 instrument 5 covering the 3 operators 50 pieces
Recommended Uncertainty pattern 5 times instrument 5 pieces of parts spanning
and Process standard standard measured standards tolerance of the measured 3 times 25 OK and
method calculation per shift for 4 measured once per product tolerance, 5
variation / measured 10 50 times (Minitab measured 12 product, measured 3 25 NOT OK (Example AIAG)
w eeks (100 operator pairs measured by
resolution ≥10 times Example) times each times by each
readings) each operator
operator
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
MSA by attributes
50 pieces were taken for visual inspection and a Reproducibility and Repeatability analysis.
Three operators inspected each part three times each.
MSA by attributes
Effectiveness
≥90% Acceptable
≥80% Marginal
<80% Not acceptable
Kappa
<0.4 Bad
> 0.75 Good to excellent
Effectiveness
≥90% Acceptable
≥80% Marginal
<80% Not acceptable
Kappa
<0.4 Bad
> 0.75 Good to excellent
MSA by attributes
Effectiveness
≥90% Acceptable
≥80% Marginal
<80% Not acceptable
Kappa
<0.4 Bad
> 0.75 Good to excellent
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
MSA by attributes
Agreement Study with Minitab Assistant
% GR & R:
Tolerance /
<10% is % GR & R: <10%
resolution % agreement:
Acceptable 10% is Acceptable 10%
≥10 and The 95% bias Bias: p-value> ≥ 90% Acceptable ≥ 80%
AIAG acceptance No out of to 30% to 30% Acceptable
None Process interval None 0.05 Linearity: p- None Marginal <80% Not
criteria control points Acceptable with with improvement
variation / contains zero. value> 0.05 Acceptable Kappa: <0.4 Bad>
improvement plan. > 30% Not
resolution 0.75 Good to excellent
plan. > 30% Not Acceptable ndc≥ 5
≥10
Acceptable
Practical:% GR &
Practical:% GR &
R: <10% is % GR & R: <10% is
GM: Uncertainty VDA: GM: Bias less VDA: Cg> 1.33 R: <10% is
Practical: No GM: Bias and Acceptable 10% Acceptable 10% to Practical:% agreement: ≥
<5% of Resolution than 10% of and Cgk> 1.33 Acceptable 10% to
Other acceptance points outside linearity <10% to 30% 30% Acceptable with 90% Acceptable ≥ 80%
product <5% of the tolerance Resolution <5% 30% Acceptable
criteria the control of product Acceptable with improvement plan. > Marginal <80% Not
tolerance product of the of product with improvement
limits tolerance improvement 30% Not Acceptable Acceptable
(Example) tolerance product tolerance plan. > 30% Not
plan. > 30% Not ndc≥ 5
Acceptable ndc ≥ 5
Acceptable
1 instrument for
1 instrument for each 1 instrument for each
Number of studies each type of 1 measuring system for each
All instruments All instruments As required All instruments All instruments As required type of measurement type of measurement
(recommended) measurement type of measuring system
system system
system
Frequency (AIAG /
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
IATF)
• Thank you