Minitab limit definition from R & R

#1
Hi everyone,
I have recently started to use minitab and since 3-4 weeks I have a problem.
We have a new machine in factory and products.
The problem is we don't know how to qualify machine as we don't know the limits related to our products. We would like to detemine product limits experimentally.

The machine has 3 palettes which carry products.

My boss demanded me to run R & R first, and I have run it 3 palettes, 10 samples, 3 times and I have the values.

Now, client demand me to find limit values of the products from obtained R & R results.
I can simply give them the mean value and 6*standart deviaiton as limits but my boss warned me that will be only valid for the samples that we have tested and there is a risque that we will not be correct in future.

At this point I need your help dear professionnals.

How can I determine limits from my R & R results in minitab and determine which samples are our of limit. As currently the machine has no limits, it can say all samples are good so I don't know which samples are good in this test conditions.

I need a setup of the limits first from R & R values and also determine if some of the samples in R & R study is good / bad according to those experimentally determined limits.

For information, I am totally beginner in this minitab subject and statistical analysis. So, please help me and with specific explications so that I can understand.

Thank you very much.

Sincerly.
 
Elsmar Forum Sponsor

Statistical Steven

Statistician
Staff member
Super Moderator
#2
Gage R&R studies are not statements about the product, but the measurement system. You cannot or should not set product specifications based on the data from a R&R study.
 

optomist1

A Sea of Statistics
Trusted Information Resource
#3
Amen, others in industry have attempted the same.....good call, its is more accurate (no pun intended) to use the Measurement System Analysis, in lieu of Gage R&R - Optomist1
 

Miner

Forum Moderator
Staff member
Admin
#4
The previous posters are correct. You need to perform a study that includes the process stream variation (i.e., pallet to pallet) and the longer term variation (e.g., setup to setup, batch to batch, etc.). Very few R&R studies would include all these sources of variation and the sample size of 10 is way too small. You need at least 100.

Since you do not have specifications yet, you can't perform a true capability study, but Minitab does have a "Tolerance Interval" analysis that will return tolerance intervals for a specified percentage of the population. If you specify 100%, it will return intervals that should yield a Cp/Cpk = 1. You will want to increase the tolerance interval to ensure you have better Cp/Cpk results.
 
Last edited:
#5
Dear all,
Thank you very much for your input.
We have decided to conduct more studies. If the things willl change / improve, I wil llet you know. thank you for your help.
Sincerly.
 
Thread starter Similar threads Forum Replies Date
S CpK in Minitab when 0.0 is the lower spec limit Statistical Analysis Tools, Techniques and SPC 7
D Control limit calculation (Xbar R charts) using Minitab Statistical Analysis Tools, Techniques and SPC 14
G Changing LCL (Lower Control Limit) on a Minitab Control Chart Using Minitab Software 13
Z Minitab - Updating Graph with specific data points Using Minitab Software 2
S Need help with analysing a survey on minitab Using Minitab Software 1
M Minitab assistant: 1-Sample % Defective Test Using Minitab Software 1
0 Interesting Discussion Analysis of half normal distribution in minitab Using Minitab Software 11
G Batch printing reports in Minitab Using Minitab Software 3
B Minitab Type 1 Gage Study on True Position Question Measurement Uncertainty (MU) 1
V Minitab GRR crossed Xbar and r method macro needed Using Minitab Software 7
I Number of decimals in equation calculated by MiniTab Using Minitab Software 0
A Acceptance p-value for linearity and bias analysis in minitab results Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 0
M How to change the display of optimization plot in Minitab 18 Using Minitab Software 2
M Minitab tool to evaluate PM (Preventive Maintenance) process Using Minitab Software 6
E Input to ANOVA 1-WAY - How can I perform this analysis in minitab? Using Minitab Software 2
N Tolerance Interval plots in Minitab Statistical Analysis Tools, Techniques and SPC 0
J Including Repeats in DoE using Minitab Using Minitab Software 5
A Minitab 18: How to automate GRR Summary Table save Reliability Analysis - Predictions, Testing and Standards 1
N What subcommands can be used with "Stop" in Minitab 18? Using Minitab Software 8
S Minitab - Factor Analysis: Label on second series of data for Biplot Using Minitab Software 4
J Which Anova dropdown to use for R&R in Minitab? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
J DoE - Number of runs in Plackett-Burman (Minitab) Using Minitab Software 2
D Asterix when pasting a column of values from Excel into Minitab (V17) Using Minitab Software 5
A Generating samples from a population in Minitab Using Minitab Software 0
Ron Rompen Random data generation in Minitab Statistical Analysis Tools, Techniques and SPC 2
I DOE: High variance and small effects in Minitab Using Minitab Software 1
B Informational Expanded Gage R&R Analysis using Minitab Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 18
R Rank Deficiency Error Minitab Using Minitab Software 5
H Minitab 15 - Factorial Design - 3 factors: 4x3x2 - How to? Using Minitab Software 4
A Capability Analysis for Packaging Seal Strength with spec. >0.1 Kgf using Minitab Using Minitab Software 6
Coury Ferguson MiniTab 17 Question-Standard Deviation Default Capability, Accuracy and Stability - Processes, Machines, etc. 5
N Regression Model (Minitab 18) - Which values my input parameters should have Using Minitab Software 2
L MINITAB 17 - Changing Data Using Minitab Software 3
R Conjoint Analysis - Minitab 18 Statistical Analysis Tools, Techniques and SPC 2
F How to make an ANOVA of a design with repeats (not replicates) in Minitab? Using Minitab Software 18
W Definitive screening design in Minitab 17 Manufacturing and Related Processes 1
S Minitab runs at different speeds on identical PCs Using Minitab Software 5
S Response Surface Method to create design matrix in Minitab Using Minitab Software 5
G ANOVA GR&R: Minitab vs AIAG MSA results Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 7
S Standard Deviation Selection on Control Charts - Minitab "pooled deviation" Statistical Analysis Tools, Techniques and SPC 3
P Minitab Data Analysis - Understanding if a Process is in Control or Not Using Minitab Software 2
P Basic Minitab Help - It's about Linear Regression Using Minitab Software 1
A Taguchi Minitab - Continuous Data - What should I choose as response variable? Using Minitab Software 3
K Taguchi Experiments for Factorial Design Analysis - Reliability of Minitab Results Using Minitab Software 1
G How to create a mixed OAs in Minitab Using Minitab Software 1
V Looking for advice on Pooled Standard Deviation between Minitab and MS Excel Statistical Analysis Tools, Techniques and SPC 1
N DOE (design of experiments) in Minitab 16 Using Minitab Software 6
R How To Calculate & Print CDF and Lower Bound CDF value for some t(time) with Minitab? Using Minitab Software 1
D minitab macro to pull access query with parameters Using Minitab Software 1
B Could I combine IQ, OQ and PQ for Minitab Software Validation ? Software Quality Assurance 3

Similar threads

Top Bottom