ng bb 23 measurement system analysis - introduction

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  • 1. UNCLASSIFIED / FOUO UNCLASSIFIED / FOUONational Guard Black Belt TrainingModule 23 Measurement System Analysis (MSA)Introduction UNCLASSIFIED / FOUO UNCLASSIFIED / FOUO

2. UNCLASSIFIED / FOUOCPI Roadmap Measure 8-STEP PROCESS 6. See 1.Validate2. Identify 3. Set4. Determine5. Develop 7. Confirm8. StandardizeCounter-the Performance ImprovementRoot Counter- ResultsSuccessfulMeasuresProblem GapsTargetsCause Measures & ProcessProcessesThroughDefineMeasure Analyze ImproveControl TOOLSProcess MappingACTIVITIES Map Current Process / Go & SeeProcess Cycle Efficiency/TOC Identify Key Input, Process, Output Metrics Littles Law Develop Operational Definitions Operational Definitions Develop Data Collection PlanData Collection Plan Validate Measurement System Statistical Sampling Collect Baseline Data Measurement System Analysis Identify Performance Gaps TPM Estimate Financial/Operational Benefits Generic Pull Determine Process Stability/CapabilitySetup Reduction Complete Measure Tollgate Control ChartsHistogramsConstraint IdentificationProcess Capability Note: Activities and tools vary by project. Lists provided here are not necessarily all-inclusive.UNCLASSIFIED / FOUO 2 3. UNCLASSIFIED / FOUO Learning Objectives Understand the importance of good measurements Understand the language of measurement Understand the types of variation in measurement systems UNCLASSIFIED / FOUO 3 4. UNCLASSIFIED / FOUO Exercise: The Three RsUNCLASSIFIED / FOUO 4 5. UNCLASSIFIED / FOUO Examples The Hale Koa Hotel manager wants to reduce customer check-in time The VA wants to reduce VA Home Loan Guarantee Program processing errors The Army Community Service organization wants to improve its customer service performance A VA Hospital is interested in finding ways to improve in-patient and out-patient careUNCLASSIFIED / FOUO 5 6. UNCLASSIFIED / FOUO Why Is MSA Important? Our ability to assess the performance of a process we wishto improve is only as good as our ability to measure it The measurement system is our eyes for our process We need to be able to see the performance of ourprocess clearly in order to improve it Sometimes, improving the ability to measure ourprocess results in immediate process improvementsCan you trust your measurements to tell you the truth? Measurement System AnalysisUNCLASSIFIED / FOUO 6 7. UNCLASSIFIED / FOUOSources Of Observed Process Variation Observed Variation Observed VariationActual Process VariationActual Process Variation Measurement Variation Measurement Variation - Long-term Process Variation - Short-term Process VariationVarianceVarianceVariance VarianceDue to InstrumentDue to InstrumentDue to Operators Due to Operators - Repeatability- Reproducibility - Calibration - Stability - Linearity The variation due to the measurement system must be identified first,then separated from actual process variationUNCLASSIFIED / FOUO 7 8. UNCLASSIFIED / FOUO Variation Is Additive Measured values Actual valuess2 Observed = s2 Measurement + s2 Part + s2 Errors2 Measurement = s2 Observed s2 Part s2 Errors2 Measurement = s2 Repeatability + s2 Reproducibility + s2 ErrorUNCLASSIFIED / FOUO 8 9. UNCLASSIFIED / FOUO Why Worry About Measurement Variation? Consider the reasons why we measure:Assist in Verify processHow might measurement continuous conformity tovariation affect these decisions? improvement specificationsactivitiesWhat if the amount ofProcess Processmeasurement variation is unknown MeasurementMeasurement ?Measurement variation can make our process capabilities appear worse than they are. UNCLASSIFIED / FOUO 9 10. UNCLASSIFIED / FOUO Measurement Variation Measurement Variation is broken down into two components: (Thetwo Rs of Gage R&R) Reproducibility (Equipment or Gage or Operator Variability) Different individuals get different measurements for the same thing Repeatability (Equipment or Gage or Operator Variability) A given individual gets different measurements for the same thing when measured multiple times The tool we use to determine the magnitude of these two sources ofmeasurement system variation is called Gage R&RUNCLASSIFIED / FOUO 10 11. UNCLASSIFIED / FOUO Reproducibility (Operators Precision) Reproducibility is the variation in the average of the measurements made by different operators using the same measuring instrument when measuring the identical characteristic on the same part Inspector As s s2m2g 2 oInspector BInspector CUNCLASSIFIED / FOUO 11 12. UNCLASSIFIED / FOUO Repeatability (Gage Precision) Repeatability is the variation between successive measurements of the same part, same characteristic, by the same person using the same equipment (gage). Also known as test /re-test error, used as an estimate of short-term variation. Ideal Process Targets s s 2 m2g2oUNCLASSIFIED / FOUO 12 13. UNCLASSIFIED / FOUO Measurement ErrorGage R & R variation is the percentage that Generally recognized criteria for measurement variation (repeatability and gage acceptability is whenreproducibility) represents of the variation observed Gage R & R variability to processin the processvariability is :Under 10%: Acceptable gage10% to 30%: Might be Observed MeasurementsacceptableOver 30%: Gage isunacceptable and should becorrected or replacedTrue Values Measurement Error Bias Gage R&R StabilityDiscriminationLinearityRepeatabilityReproducibilityOperatorOperator * Part UNCLASSIFIED / FOUO 13 14. UNCLASSIFIED / FOUO Bias (Instrument Accuracy) Bias is the difference between the observed average value of measurements and the master value. The master value is determined by precise measurement typically by calibration tools linked to an accepted, traceable reference standard.Master Value (Reference Standard) Average ValueUNCLASSIFIED / FOUO 14 15. UNCLASSIFIED / FOUO Stability Stability = If measurements do not change or drift over time, the instrument is considered to be stable Time One Time Two UNCLASSIFIED / FOUO 15 16. UNCLASSIFIED / FOUO Discrimination Discrimination is the capability of detecting small changes in thecharacteristic being measured The instrument may not be appropriate to identify process variation or quantifyindividual part characteristic values if the discrimination is unacceptable If an instrument does not allow differentiation between common variation inthe process and special cause variation, it is unsatisfactory.28.28Ruler.28.28.279 .282Caliper .282 .279.2794.2822 Micrometer.2819.2791UNCLASSIFIED / FOUO 16 17. UNCLASSIFIED / FOUO Linearity Ameasure of the difference in bias (or offset) over the range of the sample characteristic the instrument is expected to see determines linearity. If the bias is constant over the range of measurements, then linearity is good. Over what range of values for a given characteristic can the device be used? When the measurement equipment is used to measure a wide range ofvalues, linearity is a concern.Measurement Variation LowHigh EndMeasurement Scale End UNCLASSIFIED / FOUO 17 18. UNCLASSIFIED / FOUO Name That Problem!Master ValueInstrument 1 Instrument 2Average ValueMaster Value(Reference Standard)Time OneTime Two .28 1. Discrimination .2792. Bias/Accuracy .2791 3. Repeatability 4. Reproducibility Inspector A 5. Instrument Bias Inspector B Inspector C 6. StabilityUNCLASSIFIED / FOUO 18 19. UNCLASSIFIED / FOUOMeasurement Systems Analysis Template The Measurement System used to collect data has been calibrated and is considered to have no potential for significant errors. The data collection tool is reliable, can be counted on, has good resolution, shows no signs of bias and is stable.Type ofMeasurementDescriptionConsiderations to this Project Error The ability of the measurementWork hours can be measured to