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MEASURE PHASE MEASURE PHASE

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Page 1: Measure Phase

MEASURE PHASEMEASURE PHASE

Page 2: Measure Phase

Purposes of the Measure Purposes of the Measure PhasePhase

To focus the improvement effort by To focus the improvement effort by gathering information about the current gathering information about the current situationsituation

To define one or more CTQ To define one or more CTQ characteristics ( dependent characteristics ( dependent variables),map the process in detail, variables),map the process in detail, evaluate the measurement systems, evaluate the measurement systems, assess the current level of process assess the current level of process performance to establish a baseline performance to establish a baseline capability, the short and long term capability, the short and long term process sigma capabilities, and quantify process sigma capabilities, and quantify the problemthe problem

Page 3: Measure Phase

Measure Phase ActivitiesMeasure Phase Activities

Most important tools used in the Most important tools used in the Measure PhaseMeasure Phase Process mappingProcess mapping YX diagramsYX diagrams Failure modes and effects analysis Failure modes and effects analysis

( FMEA)( FMEA) Measurement systems analysis Measurement systems analysis

( MSA)( MSA) Capability analysisCapability analysis

Page 4: Measure Phase

Measure Phase ActivitiesMeasure Phase Activities

Map the process in detailMap the process in detail Process mapping helps a project Process mapping helps a project

team do the following:team do the following: Describe how activities are being doneDescribe how activities are being done Understand the big pictureUnderstand the big picture Identify how, when, or where a process Identify how, when, or where a process

should be measuredshould be measured Investigate where problems might occurInvestigate where problems might occur Identify where modifications might best Identify where modifications might best

be madebe made

Page 5: Measure Phase

Measure Phase ActivitiesMeasure Phase Activities

Map the process in detailMap the process in detail A process map consists of A process map consists of

flowcharts of the steps in a process– flowcharts of the steps in a process– operations, decision points, delays, operations, decision points, delays, movements, handoffs, rework loops, movements, handoffs, rework loops, and control or inspectionsand control or inspections

Mapping a process in detail should Mapping a process in detail should be an iterative process, as the team be an iterative process, as the team learns more about the processlearns more about the process

Page 6: Measure Phase

Measure Phase ActivitiesMeasure Phase Activities

Map the process in detailMap the process in detail

Process maps must identify forms of Process maps must identify forms of wastewaste

All wastes are influenced by and related All wastes are influenced by and related to process bottlenecks and the inability to process bottlenecks and the inability of the process to flow smoothlyof the process to flow smoothly

Page 7: Measure Phase

Measure Phase ActivitiesMeasure Phase Activities

A process map is a graphical A process map is a graphical representation of a process that is representation of a process that is used to identify the following:used to identify the following: All steps as value-added and non-value All steps as value-added and non-value

addedadded Key process inputs ( X’s)Key process inputs ( X’s) Key process outputs ( Y’s)Key process outputs ( Y’s) Data collection pointsData collection points First X’s to put into a FMEAFirst X’s to put into a FMEA Cycle time per stepCycle time per step

Page 8: Measure Phase

Create a YX MatrixCreate a YX Matrix

Takes information first identified in Takes information first identified in the process-mapping exercise and the process-mapping exercise and then documented through then documented through brainstorming methods like the cause brainstorming methods like the cause and effect diagram and effect diagram

Method for quantifying and Method for quantifying and prioritizing the strength of the prioritizing the strength of the relationships between the input relationships between the input variables( X’s) and the output variables( X’s) and the output variables ( Y’s)variables ( Y’s)

Page 9: Measure Phase

Create a YX MatrixCreate a YX Matrix

Helps start thinking analytically Helps start thinking analytically about the process and facilitates about the process and facilitates buy-in for the solutions laterbuy-in for the solutions later

Key success factor in the use of Key success factor in the use of the tool: team make-upthe tool: team make-up

Page 10: Measure Phase

Create a YX MatrixCreate a YX Matrix

Steps for creating a YX diagram:Steps for creating a YX diagram: 1- Call a team meeting and introduce 1- Call a team meeting and introduce

the concepts of the YX diagram and the concepts of the YX diagram and assemble the list of potential X’s assemble the list of potential X’s from the 3 sources: process from the 3 sources: process mapping, brainstorming and mapping, brainstorming and preliminary data analysispreliminary data analysis

2- Enter the process name and 2- Enter the process name and revision date in the matrix revision date in the matrix information sectioninformation section

Page 11: Measure Phase

Create a YX MatrixCreate a YX Matrix

Steps for creating a YX diagram:Steps for creating a YX diagram: 3- Enter the Y’s deemed important 3- Enter the Y’s deemed important

by the team and/or customerby the team and/or customer 4- Score each Y from 1 to 104- Score each Y from 1 to 10 5- Enter all potential X’s felt to 5- Enter all potential X’s felt to

impact Yimpact Y 6- Score the impact of each X on 6- Score the impact of each X on

each Yeach Y 7- Analyze the results7- Analyze the results

Page 12: Measure Phase

Create a YX MatrixCreate a YX Matrix

YX Diagram: Priority compass to YX Diagram: Priority compass to indicate where to start looking indicate where to start looking for the practical factors causing for the practical factors causing the defectthe defect

Page 13: Measure Phase

Failure Modes and Effects Failure Modes and Effects AnalysisAnalysis

Technique allowing to study all Technique allowing to study all possible problems in a process, the possible problems in a process, the potential impact of each problem, and potential impact of each problem, and how to deal with each problemhow to deal with each problem

FMEA starts with tribal knowledge, FMEA starts with tribal knowledge, known defects, and current data known defects, and current data collectioncollection

FMEA is not a tool to resolve the X’s FMEA is not a tool to resolve the X’s that cause Y’s and eliminate X’sthat cause Y’s and eliminate X’s

Page 14: Measure Phase

Failure Modes and Effects Failure Modes and Effects AnalysisAnalysis

Main steps for conducting an Main steps for conducting an FMEA:FMEA: List process functions ( steps)List process functions ( steps) List potential failure modesList potential failure modes List potential failure effectsList potential failure effects Assign severity of each effectAssign severity of each effect List potential failure causesList potential failure causes Assign occurrence level to each Assign occurrence level to each

causecause

Page 15: Measure Phase

Failure Modes and Effects Failure Modes and Effects AnalysisAnalysis

Main steps for conducting an FMEA:Main steps for conducting an FMEA: List current process controls for the List current process controls for the

prevention / detection of failure modesprevention / detection of failure modes Assign detection levels to failure modesAssign detection levels to failure modes Calculate the risk priority numberCalculate the risk priority number Specify recommended actionsSpecify recommended actions Assign responsibilityAssign responsibility Assign actions to be takenAssign actions to be taken Recalculate the risk priority numberRecalculate the risk priority number

Page 16: Measure Phase

Failure Modes and Effects Failure Modes and Effects AnalysisAnalysis

Description of some terms:Description of some terms: SEV rating ( severity) ( 1 to 10): SEV rating ( severity) ( 1 to 10):

seriousness of the falure modeseriousness of the falure mode OCC rating ( occurrence) ( 1 to 10): OCC rating ( occurrence) ( 1 to 10):

probability that failure mode will occurprobability that failure mode will occur DET rating ( 1 to 10): ability of controls to DET rating ( 1 to 10): ability of controls to

find the failure modefind the failure mode RPN ( risk priority number): overall rating RPN ( risk priority number): overall rating

calculated by multiplying the 3 ratings: calculated by multiplying the 3 ratings: SEV, OCC and DETSEV, OCC and DET

Page 17: Measure Phase

Failure Modes and Effects Failure Modes and Effects AnalysisAnalysis

Practical rules for using an FMEA:Practical rules for using an FMEA: An RPN greater than 80 is an indicator of An RPN greater than 80 is an indicator of

a critical need for immediate actiona critical need for immediate action A severity rating greater than 5 starts into A severity rating greater than 5 starts into

safety-related defectssafety-related defects A high RPN with a low probability of A high RPN with a low probability of

detection P(DET) is likely to result in detection P(DET) is likely to result in defects escaping internal tests and defects escaping internal tests and reaching customersreaching customers

A high probability of occurrence is an A high probability of occurrence is an indicator of poor capabilityindicator of poor capability

Page 18: Measure Phase

Conduct a Measurement Conduct a Measurement System AnalysisSystem Analysis

If variation due to the process If variation due to the process use of statistical process control use of statistical process control to identify the sources and to identify the sources and reducing that variation as much reducing that variation as much as possibleas possible

Page 19: Measure Phase

Conduct a Measurement Conduct a Measurement System AnalysisSystem Analysis

If variation due to the If variation due to the measurement system, errors can measurement system, errors can be classified into two categories:be classified into two categories: Accuracy: difference between Accuracy: difference between

recorded measurements and actual recorded measurements and actual value for the parts measuredvalue for the parts measured

Precision: variation in Precision: variation in measurements when a device is measurements when a device is used to measure the same part used to measure the same part repeatedlyrepeatedly

Page 20: Measure Phase

Conduct a Measurement Conduct a Measurement System AnalysisSystem Analysis

Accuracy: 3 componentsAccuracy: 3 components Stability: freedom from special Stability: freedom from special

cause variation over timecause variation over time Bias: influence of any factor that Bias: influence of any factor that

causes the sample data to appear causes the sample data to appear different from what it actually isdifferent from what it actually is

Linearity: statistical consistency in Linearity: statistical consistency in measurements over the full range of measurements over the full range of expected valuesexpected values

Page 21: Measure Phase

Conduct a Measurement Conduct a Measurement System AnalysisSystem Analysis

Precision: 2 componentsPrecision: 2 components Reproducibility: variation due to the Reproducibility: variation due to the

measurement systemmeasurement system Repeatability: variation due to the Repeatability: variation due to the

measuring devicemeasuring device

Page 22: Measure Phase

Conduct a Measurement Conduct a Measurement System AnalysisSystem Analysis

Reproducibility and repeatability are Reproducibility and repeatability are the object of a specific study called a the object of a specific study called a gauge repeatability and gauge repeatability and reproducibility studyreproducibility study Can be performed on both attribute-based Can be performed on both attribute-based

and variable-based measurement systemsand variable-based measurement systems Attributes data: fit into categories that can be Attributes data: fit into categories that can be

described in terms of words ( such as good or described in terms of words ( such as good or bad, pass or fail,..) and countedbad, pass or fail,..) and counted

Variables data: quantitative data consisting of Variables data: quantitative data consisting of discrete data that are counted and continuous discrete data that are counted and continuous data that are on a continuum, usually in data that are on a continuum, usually in decimal formdecimal form

Page 23: Measure Phase

Determine the process Determine the process capabilitycapability

Determine whether a process, given its Determine whether a process, given its natural short term variation, has the natural short term variation, has the potential long term capability to meet potential long term capability to meet established customer requirements or established customer requirements or specificationsspecifications A short term capability study covers a A short term capability study covers a

relatively short period of time and consists of relatively short period of time and consists of 30 to 50 data points30 to 50 data points

It measures the potential ( short term) capability of It measures the potential ( short term) capability of the processthe process

This method of estimating sigma considers the This method of estimating sigma considers the variation within a subgroupvariation within a subgroup

Does not consider the shift and drift between or Does not consider the shift and drift between or among subgroupsamong subgroups

Page 24: Measure Phase

Determine the process Determine the process capabilitycapability

A long term capability study covers A long term capability study covers a relatively long period of time and a relatively long period of time and consists of 100-200 data pointsconsists of 100-200 data points Measures the actual ( long term) Measures the actual ( long term)

capability of the processcapability of the process Total standard deviation says to Total standard deviation says to

estimate sigma considering the estimate sigma considering the variation both within and between variation both within and between or among subgroupsor among subgroups

Page 25: Measure Phase

Determine the process Determine the process capabilitycapability

A subgroup is a logical grouping of A subgroup is a logical grouping of objects or events that displays only objects or events that displays only random event-to-event variationsrandom event-to-event variations The objects or events are grouped to The objects or events are grouped to

create homogenous groups free of create homogenous groups free of assignable or special causesassignable or special causes

By virtue of the minimum within-group By virtue of the minimum within-group variability, any change in the central variability, any change in the central tendency or variance of the universe will tendency or variance of the universe will be reflected inthe subgroup-to-subgroup be reflected inthe subgroup-to-subgroup variabilityvariability

Page 26: Measure Phase

Conduct the Measure Conduct the Measure Phase- Gate ReviewPhase- Gate Review

The black belt reports to the executive The black belt reports to the executive team on the status of the projectteam on the status of the project

To prepare for the review, the black To prepare for the review, the black belt and the champion should meet to belt and the champion should meet to discuss questions such as the following:discuss questions such as the following: What is the main problem?What is the main problem? How have you selected critical measures?How have you selected critical measures? In what ways have you validated the In what ways have you validated the

measurement system?measurement system? What is the current process capability?What is the current process capability?