【正文】 ation (?m) is not known, the total variation can be estimated using the data in the study. First the part variation is determined: Rp is the range of the part averages, while K3 is a constant based on the number of parts in the study. The total variation (TV) is just the square root of the sum of the squares of Ramp。R study: 1. Verify calibration of measurement equipment to be studied. 2. Obtain a sample of parts that represent the actual or expected range of process variation. 3. Add a concealed mark to each identifying the units as numbers 1 through 10. It is critical that you can identify which unit is which. At the same time it is detrimental if the participants in the study can tell one unit from the other (may bias their measurement should they recall how it measured previously). 4. Request 3 appraisers. Refer to these appraisers as a A, B, and C appraisers. If the measurement will be done repetitively such as in a production environment, it is preferable to use the actual appraiser that will be performing the measurement. For extreme cases, a minimum of two appraisers can be used, but this is strongly discouraged as a less accurate estimate of measurement variation will result. 5. Let appraiser A measure 10 parts in a random order while you record the data noting the concealed marking. Let appraisers B and C measure the same 10 parts Note: Do not allow the appraisers to witness each other performing the measurement. The reason is the same as why the unit markings are concealed, TO PREVENT BIAS. 6. Repeat the measurements for all three appraisers, but this time present the samples to each in a random order different from the original measurements. This is to again help reduce bias in the measurements. Analysis Techniques: Variable Gage Analysis …… 10 Parts 3 Appraisers 3 Trials 1. The Average and Range Method: A range control chart is created to determine if the measurement process is stable and consistent. For each appraiser calculate the range of the repeated measurements for the same part. Analysis Techniques: Variable Gage Analysis Range of Repeated Measures0102030401A 2A 3A 4A 5A 1B 2B 3B 4B 5B 1C 2C 3C 4C 5CM i nXXRR a n g e M a x ??Analysis Techniques: Variable Gage Analysis The average range for each operator is then puted. The average of the measurements taken by an operator is calculated. A control chart of ranges is created. The centerline represents the average range for all operators in the study, while the upper and lower control limit constants are based on the number of times each operator measured each part (trials). P ar t s of N o.R??O p e r a to rRP a r tsT r ia lsXXO p e r a to r *??Analysis Techniques: Variable Gage Analysis RDL C LRDUCLRRRR34O pe r a t o r s N o . o f????The centerline and control limits are graphed onto a control chart and the calculated ranges are then plotted on the control chart. The range control chart is examined to determine measurement process stability. If any of the plotted ranges fall outside the control limits the measurement process is not stable, and further analysis should not take place. However, it is mon to have the particular operator remeasure the particular process output again and use that data if it is incontrol. Analysis Techniques: Variable Gage Analysis Repeatability Equipment Variation (.) The constant d2* is based on the number of measurements used to pute the individual ranges(n) or trials, the number of parts in the study, and the number of different conditions under study. The constant K1 is based on the number of times a part was repeatedly measured (trials). The equipment variation is often pared to the process output tolerance or process output variation to determine a percent equipment variation (%EV). 12** KRdREV ??10 0*)(%10 0*)(%mEVP R O CEVLS LU S LEVTO LEV????Analysis Techniques: Variable Gage Analysis Reproducibility Appraiser Variation(.) Xdiff is the difference between the largest average reading by an operator and the smallest average reading by an operator. The constant K2 is based on the number of different conditions analyzed. The appraiser variation is often pared to the process output tolerance or process output variation to determine a percent appraiser variation (%AV). ? ? ?????????ntEVKXAVD iff222* 100*)(%100*)(%mAVP R O CAVLS LU S LAVT O LAV???Analysis Techniques: Variable Gage Analysis Repeatability and Reproducibility( Gage Ramp。 Reproducibility。 Stability。 Training Material for MEASUREMENT SYSTEM ANALYSIS Contents : 1) INTRODUCTION FOR MEASUREMENT SYSTEM ANALYSIS 2) GENERAL METHODS ILLUSTRATION FOR MEASUREMENT SYSTEM ANALYSIS 1) VARIABLE GAGE ANALYSIS METHOD 1) THE AVERAGERANGE METHOD 2) THE ANOVA METHOD 1) ATTRIBUTE GAGE ANALYSIS METHOD 1) SHORT METHOD 2) HYPOTHESIS TEST ANALYSIS 3) SIGNAL DETECTION THEORY 4) LONG METHOD 3) ACCEPTABILITY CRITERIA 4) CONCLUSION 5) FOUR METHODS COMPARISON Introduction: Basic requirements by QS9000 amp。 Linearity Linearity is the difference in the bias values through the expected operating range of the measurement instrument. It is a systematic error ponent of the measurement system. Linearity Introduction: Where does the variation of measurement system e from? ? The Five Characterizations of Measurement System: 2. Width Variation: Repeatability。 Gage Ramp。R) The gage error (Ramp。R and the part variation 3KRPV p?22amp。R (P/P ratio: % total of total variance。R base on the tolerance (P/T ratio). If the measurement system is going t