# GRR (Gage R&R) Nested Anova Method Example

#### Rameshwar25

##### Quite Involved in Discussions
Dear All
Pl find attached excel sheet for calculating GRR using Anova method for Nested Study.
The attached file contains two sheets-one for 5 Parts, 3 App and 2 trials and second sheet for10 parts, 3 App and 3 trials.
The result for sheet1 have been verified using Minitab 16 and Minitab result is given in Sheet 1 in pictorial form. In fact, the data for sheet 1 are from gagenest.mtw which is supplied with Minitab 16.

Although I have prepared these sheets, i have one question left i.e. what is the use of calculating F and P values for nested study. Unlike Crossed study, we do not take any decision about interaction or non-interaction using F and P values. Then why do we need to calculate them?

I would very much appreciate some experts to answer my question and critically check the sheets.

Regards
rameshwar

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B

#### Barbara B

Rameshwar,

thanks for sharing the Excel-template

The formulas are used correctly except for ndc which is the smallest integer of the number calculated, so
ndc = 6.8334 -> ndc = 6
If ndc is less than 1, it is set to 1.

The F- and p-values in the ANOVA show if there are statistically significant differences between the readings of the operators (line "Operator" in Minitab, Appraiser in Excel-sheet) and if the measurements for different parts yield to different readings (line "Part (Operator)" in Minitab, Appraiser by part in Excel-sheet). As in the Gage R&R (crossed) you do not want to get different results with different operators, but there should be different measurements for different parts.

Due to the study design 1 part could only be measured 1 time, therefore there is no chance to calculate the difference of repeated measurements like in the Gage R&R (crossed) -> Repeatability = 0 and you can't determine an interaction between operator and part.

Best regards,

Barbara

#### Rameshwar25

##### Quite Involved in Discussions
Thank you Barbara for comments and explanation,
I am attaching file with revised formula for ndc.

Regards
Rameshwar

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#### Vitaliy Kovalchuk

##### Registered
Hello together,
what are the acceptance criterias for GRR nested? I have just transfered my data in this Excel-sheet from Rameshwar and have got the counted values.

Vitaliy

#### Rameshwar25

##### Quite Involved in Discussions
Dear Vitaliy
The acceptance critera for GRR calculated with Nested Anova Method is same as for Crossed Anova and Average & Range methods i.e. upto 10% accepted, above 10% and upto 30%-acceptable with deviation and beyond 30%- not acceptable.
I could not understand remaining part of your question. Pl clarify so that I can answer.

Regards
rameshwar

#### Vitaliy Kovalchuk

##### Registered
Thanks for confirmation, Rameshwar,
second part of my post was only like explanation. Question is fully answered.

Good luck
Vitaliy

T

#### TamTom

Dear All
Pl find attached excel sheet for calculating GRR using Anova method for Nested Study.
The attached file contains two sheets-one for 5 Parts, 3 App and 2 trials and second sheet for10 parts, 3 App and 3 trials.
The result for sheet1 have been verified using Minitab 16 and Minitab result is given in Sheet 1 in pictorial form. In fact, the data for sheet 1 are from gagenest.mtw which is supplied with Minitab 16.

Although I have prepared these sheets, i have one question left i.e. what is the use of calculating F and P values for nested study. Unlike Crossed study, we do not take any decision about interaction or non-interaction using F and P values. Then why do we need to calculate them?

I would very much appreciate some experts to answer my question and critically check the sheets.

Regards
rameshwar
Hello,

I'm not very familiar with non-replicable MSA. And my English comes to its limits by the statistic vocabulary. Please mind this by reading my question.
We perform a temperature test with an messuring rod, where "paper" thermocouples are put on, and this "system" is then put into the melted alloy.

So I don't only have a non-replicable measuring because the melt change over the time, but also the thermocouples breakes after 3 measurings.

Is the nested Anova method useable for this system?

My idea was, to have anything, to hold the sytem in a furnace, and just have Method 1.

The temperature measuring is important for the process, so I want to have it in the Control Plan, and our ne Auditors are very strikt about the ISO/TS requirement, that all measuring equipment named in the CP must have a MSA.
So I'm welcome every bit of help!

Regards,

TamTom

S

#### sinan_guler

hey i need a anova analysis for my data. here i posted my data and it should be analysed in Minitab.

Thank you very much.

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#### Bev D

##### Heretical Statistician
Staff member
Super Moderator
hey i need a anova analysis for my data. here i posted my data and it should be analysed in Minitab.

Thank you very much.
welcome to the cove!

I have a few clarifying questions:
are you asking someone here to analyze your data for you? or do you have some concerns about the data itself?
why must it be analyzed in Minitab?

S

#### sinan_guler

welcome to the cove!

I have a few clarifying questions:
are you asking someone here to analyze your data for you? or do you have some concerns about the data itself?
why must it be analyzed in Minitab?
No it can be from other softwares but i need the analysis of the data (ANOVA)

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