Presentation is loading. Please wait.

Presentation is loading. Please wait.

Repeatability & Reproducibility הישנות ו הדירות Repeatability and Reproducibility (R & R) Studies Evaluate the precision of a measurement system. It is.

Similar presentations


Presentation on theme: "Repeatability & Reproducibility הישנות ו הדירות Repeatability and Reproducibility (R & R) Studies Evaluate the precision of a measurement system. It is."— Presentation transcript:

1 Repeatability & Reproducibility הישנות ו הדירות Repeatability and Reproducibility (R & R) Studies Evaluate the precision of a measurement system. It is important that the gauge be properly calibrated Before starting the Gauge R & R Study.

2 Precision and Accuracy

3 Precision Repeatability Problem: The same person (or station) can’t get the same result twice on the same subject Reproducibility Problem: Different people (or stations) can’t agree on the result obtained on the same subject Within Inspector Errorbetween Inspector Error Precision Is the closeness of agreement between randomly selected individual measurement or test results.

4 Gauge Repeatability & Reproducibility Gage R&R is a study to measure the measurement error in measurement systems. The 10% rule tells us that if the percent of tolerance consumed by the R&R does not exceed 10%, the measurement system is excellent. R&R = 15% means that 15% of the variation in product measurements is due to the measurement System.

5 Each independent component of the model is variable: –Product quality characteristic - –Gauge, measurement error - Total observed variance in product quality characteristic measurements: Total observed variance

6 Gauge variance If more than one operator used in study then measurement (gauge) error has two components of variance: Repeatability: – - Variance due to measuring instrument Reproducibility: – - Variance due to different operators

7 Experiments to estimate the components & are called: gauge repeatability and reproducibility studies (gauge R&R studies).

8 Repeatability & Reproducibility Report n - number of parts r – number of operators For example : 2 operators, r=2 j=1…r 10 items, n=10 i=1…n

9 Repeatability = Equipment Variation Trials234 K1K Average and Range method Standard deviation for Repeatability Where d2 is a factor that depends on the number of trials (sample size): n d זהו החלק של השונות, בטווח הסיבולת, הנגרמת ע"י הציוד!

10 Average and Range method Standard deviation for Reproducibility Reproducibility = Appraiser Variation Operators234 K2K זהו החלק של השונות, בטווח הסיבולת, הנגרמת ע"י המפעילים!

11 Combined Gage Variation זהו החלק של השונות, בטווח הסיבולת, הנגרמת ע"י מערכת המדידה!


Download ppt "Repeatability & Reproducibility הישנות ו הדירות Repeatability and Reproducibility (R & R) Studies Evaluate the precision of a measurement system. It is."

Similar presentations


Ads by Google