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1、PROJECT MANAGEMENT FUNDAMENTALSProject Quality ManagementProject Quality ManagementJuly 20102Modern Quality ManagementQuality Management complements Project ManagementProject Management. For example, both disciplines recognize the importance of:Customer satisfactionUnderstanding, evaluating, definin
2、g, and managing expectations so that customer requirements are met. This requires a combination of conformance to requirements (the project must produce what it said it would produce) and fitness for use (the product or service must satisfy real needs). Prevention over inspectionThe cost of preventi
3、ng mistakes is generally much less than the cost of correcting them, as revealed by inspection. Management responsibilitySuccess requires the participation of all members of the team, but it remains the responsibility of management to provide the resources needed to succeed. Continuous improvementTh
4、e plan-do-check-act cycle is the basis for quality improvement (as defined by Shewhart and modified by Deming, in the ASQ Handbook.)348.1 PLAN QUALITY8.1 PLAN QUALITYThe Plan Quality Process refers to identifying which quality standards are relevant to the project and determining how to satisfy them
5、. It is part of the Planning process group.5Plan Quality Tools and TechniquesPlan Quality Tools and TechniquesCost-Benefit AnalysisCost-Benefit AnalysisNot just a comparison between two options.Need to look at the best approach to achieve quality in the project in relation to the monies to complete
6、the work.The study of the quality received in proportion tothe cost to reach those quality expectations.Quality should meet, not exceed, customers expectations6Plan Quality Tools and TechniquesPlan Quality Tools and TechniquesBenchmarking and DOEBenchmarking and DOEBenchmarkingBenchmarkingComparing
7、two similar things to measure which one performs best.Examines project practices against other projects to measure performance, and then selects the best practices for performance in the current projectDesign of Experiments (DOE)Design of Experiments (DOE)A statistical method (what-if scenarios) tha
8、t helps identify which factors may influence specific variables of a product or process under development or in production. Most often used on the product of the project rather than the project itself, however could be used in determining the most efficient crew of resources to put on an activity. 7
9、Plan Quality Tools and TechniquesPlan Quality Tools and TechniquesCost Of QualityCost Of Quality“total costs incurred by investment in preventing nonconformance to requirements, appraising the product or service for conformance to requirements, and failing to meet requirements (rework)”Failure costs
10、 (internal and external) are also called cost of poor quality.PMI emphasizes that quality should be planned into the project, not inspected in. They also advocate the DemingDeming approach:85% of costs of quality are Management responsibility85% of costs of quality are Management responsibilityCosts
11、 of ConformanceCosts of NonconformanceQuality TrainingReworkStudiesScrapSurveysInventory costsValidation and auditsWarranty costs8Plan Quality Tools and TechniquesPlan Quality Tools and TechniquesOther Tools & TechniquesOther Tools & TechniquesBrainstormingBrainstormingA general data gathering and c
12、reativity technique that can be used to identify risks, ideas, or solutions to issues by using a group of team members or subject-matter experts. Typically, a brainstorming session is structured so that each participants ideas are recorded for later analysis. Affinity DiagramsAffinity DiagramsThe af
13、finity diagram is a business tool and is one of the “seven management and planning tools” and is a tool used to organize ideas and data.The tool is commonly used within project management and allows large numbers of ideas to be sorted into groups for review and analysis Force Field AnalysisForce Fie
14、ld AnalysisA useful technique for looking at all the forces for and against a decision. In effect, it is a specialized method of weighing pros and cons.9Plan Quality Tools and TechniquesPlan Quality Tools and TechniquesOther Tools & TechniquesOther Tools & TechniquesNominal Group TechniquesNominal G
15、roup TechniquesA decision-making method using a voting process for use among groups of many sizes. First, every member of the group gives their view of the solution, with a short explanation. Then, duplicate solutions are eliminated from the list of all solutions, and the members proceed to rank the
16、 solutions, 1st, 2nd, 3rd, 4th, and so on. The numbers each solution receives are totaled, and the solution with the lowest (i.e. most favored) total ranking is selected as the final decision. There are variations on how this technique is used.FlowchartsFlowchartsThe depiction in a diagram format of
17、 the inputs, process actions, and outputs of one or more processes within a system.10Plan Quality OutputsPlan Quality OutputsQuality Management PlanQuality Management PlanIt describes how the project management team will implement the quality policy.It is a component of the overall Project Managemen
18、t Plan, and will address the following:Quality ControlQuality Control Monitoring work results to see if they meet relevant quality standards. If standards are not met, PM analyzes to determine root cause and then “eliminates it”.Quality AssuranceQuality Assurance Maps to the Organizations quality po
19、licy and is typically a managerial process. Generally considered the work of the applying the quality plan.Quality ImprovementQuality Improvement Corrective actions applied to improve the product and the project to meet the quality standards.11Plan Quality OutputsPlan Quality OutputsOther OutputsOth
20、er OutputsQuality MetricsQuality Metrics“An Operational definition that describes, in very specific terms, what something is and how the quality control process measures it.” (measures are actual values)Quality ChecklistsQuality ChecklistsSimple approaches to ensure that work is completed according
21、to the quality policy. Usually a list of activities that will be checked off as completed. Usually component-specific.12Plan Quality OutputsPlan Quality OutputsOther OutputsOther OutputsProcess Improvement PlanSubsidiary of the project management plan, it “details the steps for analyzing processes t
22、hat will facilitate the identification of waste and non-value added activity, thus increasing customer value, such as:Process boundaries purpose, start, end, inputs, outputs, data required, owner, etc.Process configuration flowchart with interfaces/linksProcess metrics to maintain control over statu
23、s of processesTargets for improved performance guides the process improvement activities”13Plan Quality OutputsPlan Quality OutputsOther OutputsOther OutputsQuality BaselineRecords and compares the quality objectives for the projectThe measurement of the project performance and the quality of the pr
24、oject objectivesShows the PMT where the project should be improvingProject Management Plan (Updates)14Quality vs. GradeQuality vs. GradeGrade is a way to distinguish between products with the same functional use but different technical attributes. For example:a Grade 1 bolt has a certain strength wh
25、ile a Grade 3 bolt of the same size is stronger and a Grade 5 bolt is even stronger. The Grade 1 bolt, though of low grade, can still be of high quality (no defects, of proper size, etc.)158.2 PERFORM QUALITY ASSURANCE8.2 PERFORM QUALITY ASSURANCEQuality Assurance is the application of planned, syst
26、ematic quality activities to ensure that the project will employ all processes needed to meet requirements.Occurs during the execution phase of the project. 168.2 PERFORM QUALITY ASSURANCE8.2 PERFORM QUALITY ASSURANCEPerform Quality Assurance is the process of regular structured reviews to ensure th
27、e project will comply with the planned quality standardsProvides an umbrella for another important quality activity continuous process improvement, which is an iterative means for improving the quality of all processes.Usually done by means of Quality AuditsQuality Audits.A good quality assurance sy
28、stem will:Identify objectives and standardsBe multifunctional and prevention orientedCollect and use dataEstablish performance measuresInclude a quality auditA A Quality AuditQuality Audit is is “a structured, independent review to determine whether project activities “a structured, independent revi
29、ew to determine whether project activities comply with organizational and project policies, processes, and procedures.”comply with organizational and project policies, processes, and procedures.”178.2 PERFORM QUALITY ASSURANCE 8.2 PERFORM QUALITY ASSURANCE Tools & TechniquesTools & TechniquesQuality
30、 auditsQuality audits are independent evaluations of quality performance to ensure that:Intended quality will be metProducts are safe and fit for useLaws and regulations are followedData systems are adequateCorrective action is taken, if neededImprovement opportunities are identifiedQuality standard
31、s, procedures and methods established during quality planning are reevaluated and are still relevantQuality audits may also identify the lessons learned on the current project to determent how to make things better for this project as well as for other projects within the organization18QUALITY IMPRO
32、VEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESW. Edward DemingW. Edward DemingHe prescribed 14 activities for implementing quality which include:Create constancy of purpose towards improvement of product and serviceAdopt the new philosophy. We can no longer live with commonly accepted levels of
33、 delay, mistakes and defective workmanshipCease dependence on mass inspection. Instead, require statistical evidence that quality is built inEnd the practice of awarding business on the basis of priceFind problems. It is managements job to work continually on the systemInstitute modern methods of tr
34、aining on the jobInstitute modern methods of supervision of production workers, the responsibility of foremen must be changed from numbers to qualityDrive out fear, so that everyone may work effectively for the companyBreak down barriers between departmentsEliminate numerical goals, posters and slog
35、ans for the workforce asking for new levels of productivity without providing methodsEliminate work standards that prescribe numerical quotasRemove barriers that stand between the hourly worker and their right to pride of workmanshipInstitute a vigorous programme of education and retrainingCreate a
36、structure in top management that will push on the above points every day19QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESW. Edward Deming / Walter A. ShewhartW. Edward Deming / Walter A. Shewhart4-step cycle: Plan, Do, Check, Act (PDCA)Plan, Do, Check, Act (PDCA)PlanPlan what is nee
37、dedDoDo itCheckCheck that it worksActAct to correct any problems or improve performancePDCA cycle, known as Deming cycle, has actually been developed by a colleague of Deming, Walter A. Shewhart.20QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESPhilip B. CrosbyPhilip B. CrosbyHe is k
38、nown for the two concepts of:“Quality is Free”“Quality is Free”“Zero Defects”“Zero Defects”Additionally, he stressed 4 Absolutes of Quality4 Absolutes of Quality:Quality is conformance to requirementsQuality is conformance to requirementsThe system of quality is preventionThe system of quality is pr
39、eventionThe performance standard is zero defectsThe performance standard is zero defectsThe measure of quality is the price of nonconformanceThe measure of quality is the price of nonconformance21QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESPhilip B. CrosbyPhilip B. CrosbyHe also
40、had 14 steps to improving quality:Management is committed to a formalized quality policyForm a management level quality improvement team (QIT) with responsibility for quality improvement process planning and administrationDetermine where current and potential quality problems lieEvaluate the cost of
41、 quality and explain its use as a management tool to measure wasteRaise quality awareness and personal concern for quality amongst all employeesTake corrective actions, using established formal systems to remove the root causes of problemsEstablish a zero defects committee and programTrain all emplo
42、yees in quality improvementHold a Zero Defects Day to broadcast the change and as a management recommitment and employee commitmentEncourage individuals and groups to set improvement goalsEncourage employees to communicate to management any obstacles they face in attaining their improvement goalsGiv
43、e formal recognition to all participantsEstablish quality councils for quality management information sharingDo it all over again form a new quality improvement team22QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESJoseph M. JuranJoseph M. JuranDeveloped the “fitness-for-use”“fitness
44、-for-use” concept of quality which emphasizes that the measure of high quality is achieved by ensuring that the product meets the expectations of the stakeholders and customers.His 10 steps are:Build awareness of the need and opportunity for improvementSet goals for improvementOrganize to reach the
45、goalsProvide trainingCarry out projects to solve problemsReport progressGive recognitionCommunicate resultsKeep score of improvements achievedMaintain momentum23QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESJoseph M. JuranJoseph M. JuranJuran established the so-called Juran Trilogy
46、Juran Trilogy for improving quality:Plan: attitude breakthrough, identify vital few new projectsImprove: knowledge breakthrough, conduct analysis, institute changeControl: overcome resistance, institute controlsQUALITY CONTROLQUALITY PLANNINGQUALITY IMPROVEMENTPareto Analysis, Pareto Analysis, Lesso
47、ns LearnedLessons LearnedProject-by-ProjectProject-by-ProjectHolding the GainsHolding the GainsBreakthroughBreakthrough24QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESJoseph M. JuranJoseph M. JuranQUALITY PLANNINGQUALITY PLANNINGQUALITY CONTROLQUALITY CONTROLTIMETIMEOPERATIONSOPERA
48、TIONSPercentage defecctiveQ QU UA AL LI IT TY Y I IMMP PR RO OV VE EMME EN NT TNEW ZONE OF QUALITY CONTROLORIGINAL ZONE OF QUALITY CONTROLCHRONIC WASTE(possible improvements)SPORADIC SPIKE020400LESSONS LEARNED25QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESArmand V. FeigenbaumArman
49、d V. FeigenbaumHe originated the Total Quality Control Total Quality Control, which he defined as:“An effective system for integrating quality development, quality maintenance and quality improvement efforts of the various groups within an organization, so as to enable production and service at the
50、most economical levels that allow full customer satisfaction”.Dr. Feigenbaums 3 basic steps are:Quality leadershipQuality leadershipModern quality technologyModern quality technologyOrganizational commitmentOrganizational commitment26QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESDr
51、. Kaoru IshikawaDr. Kaoru IshikawaHe is well known for his total quality perspective, company wide quality control, his attention to the human side of quality, the Ishikawa diagram and the assembly and use of the “seven basic tools of qualityseven basic tools of quality”:Pareto analysis Pareto analy
52、sis which are the main problems?Cause and effect diagrams Cause and effect diagrams what causes the problems?Stratification Stratification how is the data made up?Check sheets Check sheets how often it occurs or is done?Histograms Histograms what do overall variations look like?Scatter charts Scatte
53、r charts what are the relationships between factors?Process control charts Process control charts which variations to control and how?27QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESDr. Genichi TaguchiDr. Genichi TaguchiHe has introduced the extensive use of Design of Experiments (
54、DOE)Design of Experiments (DOE) in quality.DOE is a statistical method (what-if scenarios) that helps identify which factors may influence specific variables of a product or process under development or in production. Most often used on the product of the project rather than the project itself, howe
55、ver could be used in determining the most efficient crew of resources to put on an activity. Quality and reliability are developed off-line, during the product design phase. In fact he considered better to design a robust product, insensitive to variation in the manufacturing process, rather than co
56、ntrolling variations during manufacturing.The 3 stages of the Taguchi methodology are:System DesignSystem DesignParameter DesignParameter DesignTolerance DesignTolerance Design28QUALITY IMPROVEMENT PHILOSOPHIESQUALITY IMPROVEMENT PHILOSOPHIESShigeo ShingoShigeo ShingoHe is well known for:Just-in-Tim
57、e manufacturing, Just-in-Time manufacturing, Single Minute Exchange of Die (SMED) systemSingle Minute Exchange of Die (SMED) systemPoka-Yoke (mistake proofing) system.Poka-Yoke (mistake proofing) system. In Poka Yoke, defects are examined, the production system stopped and immediate feedback given s
58、o that the root causes of the problem may be identified and prevented from occurring again. Poka Yoke are supposed to prevent errorserrors from becoming defectsdefectsIn order to avoid making mistakes or forget something, the use of checklists is fostered.The ideal production system should have Zero
59、 quality control.298.3 PERFORM QUALITY CONTROL8.3 PERFORM QUALITY CONTROL308.3 PERFORM QUALITY CONTROL8.3 PERFORM QUALITY CONTROLThis process involves measurement of the process or performance using quality measurement of the process or performance using quality control tools; and determine whether
60、they comply with relevant quality standards control tools; and determine whether they comply with relevant quality standards and identifying ways to eliminate causes of unsatisfactory results.and identifying ways to eliminate causes of unsatisfactory results. Perform Quality Control is part of the M
61、onitoring and Controlling Process Group. A good quality control system will:Select what to controlSet standardsEstablish measurement methodsCompare actuals to standardsAct when standards are not met318.3 PERFORM QUALITY CONTROL8.3 PERFORM QUALITY CONTROLThe project team should do the following to en
62、sure competency in quality control:Conduct statistical quality control measures, such as sampling and probabilityInspect the product to keep errors away from the customerPerform attribute sampling to measure conformance to quality on a per-unit basisConduct variable sampling to measure the degree of
63、 conformanceStudy special causes to determine anomalies to qualityResearch random causes to determine expected variances of qualityCheck the tolerance range to determine if the results are within or without an acceptable level of qualityObserve control limits to determine if the results are in or ou
64、t of quality control328.3 PERFORM QUALITY CONTROL8.3 PERFORM QUALITY CONTROLQuality Control GlossaryQuality Control GlossaryPreventionPrevention: keeping errors out of the processInspectionInspection: keeping errors out of the hands of the customerAttribute samplingAttribute sampling: the result con
65、forms, or it does not Variables samplingVariables sampling: the result is rated on a continuous scale that measures the degree of conformitySpecial causesSpecial causes: unusual eventsCommon causesCommon causes (also called Random causes): normal process variation TolerancesTolerances: the result is
66、 acceptable if it falls within the range specified by the toleranceControl limitsControl limits: the process is in control if the result falls within the control limit33STATISTICAL PROCESS CONTROLSTATISTICAL PROCESS CONTROLSPC is a tool used to manage processes. It is also used as a mean for reducin
67、g the variability in products, deliveries, materials, equipment, attitudes and processes, which are the cause of most quality problems. SPC will focuses on whether a process is “in controlin control” stable and exhibiting only random variation, or “out of controlout of control” and needing attention
68、. It also gives warnings on declining performance, and can support with long-term defect reduction, detection of special or assignable causes, decrease or removal of causes of variation and achievement of a closest possible level of desired performance.In SPC, data (numbers) are the basis for decisi
69、ons and actions, and a thorough and reliable data recording system is fundamental. Furthemore, a set of tools to analyse and interpret the data is required. One of this tools is represented by CONTROL CHARTSCONTROL CHARTS.34CONTROL CHARTSCONTROL CHARTSA control chart is a statistical tool used to di
70、scriminate between variation in a process resulting from common causescommon causes or from special causesspecial causes. It is a graphic exhibit representing how stable a process is over time.Control limitsControl limits are the limits of variation that a statistically controlled process should be
71、respect. Control limits are set at +/- 3 standard deviations (3 sigma) from the centerline.Control limits must not be confused with specification limitsspecification limits, which correspond to the desired process performance.In short, control charts:Monitor process variation over timeDifferentiate
72、between special cause and common cause variationAssess effectiveness of changesCommunicate process performance35CONTROL CHARTSCONTROL CHARTSValuePercent Correct+/ 1 sigma68.26 percent +/ 2 sigma 95.46 percent +/ 3 sigma 99.73 percent +/ 6 sigma 99.99 percent36CONTROL CHARTSCONTROL CHARTSTIMETIME37CO
73、NTROL CHARTS: RULE OF SEVENCONTROL CHARTS: RULE OF SEVENUCLLCLAvg.UCLLCLAvg.UCLLCLAvg.UCLLCLAvg.TIMETIMETIMETIMETIMETIMETIMETIME38HISTOGRAMSHISTOGRAMSA Histogram is a vertical bar chart that shows the distribution of a data set. A Histogram does not represent process performance over time. Should we
74、 compare it to a control chart, the latter would be like a movie, while the former would be like a snapshot.In short, histograms:Summarize large data sets graphicallyCompare measurements to specificationsCommunicate information to the teamAssist in decision making39HISTOGRAM sampleHISTOGRAM sampleAn
75、alyzing number of shots at a certain distance from a target:40HISTOGRAM sampleHISTOGRAM sampleTARGETHITSMISSESMISSES41HISTOGRAMSHISTOGRAMS42HISTOGRAMSHISTOGRAMSTARGETTARGETTARGETTARGETSmall amount of variationLarge amount of variation43HISTOGRAMSHISTOGRAMSTARGETTARGETTARGETTARGET44HISTOGRAMSHISTOGRA
76、MSTARGETTARGETTARGETTARGET45HISTOGRAMSHISTOGRAMSTARGETTARGETTARGETTARGETLSLLSLUSLUSLUSL: Upper Specification LimitLSL: Lower Specification LimitWITHIN LIMITSOUT OF SPECS46HISTOGRAMSHISTOGRAMSTwo peaksIsolated islandunusual condition in materials and processesdata of two or more different origins are
77、 included such as products produced by two different machines, operators, shifts, etc.)47PARETO CHARTPARETO CHARTA Pareto Chart is “a series of bars whose heights reflect the frequency or impact of problems. The bars “a series of bars whose heights reflect the frequency or impact of problems. The ba
78、rs are arranged in descending order of height from left to right. This means the are arranged in descending order of height from left to right. This means the categories represented by the tall bars on the left are relatively more significant than categories represented by the tall bars on the left
79、are relatively more significant than those on the right”.those on the right”.The chart gets its name from the Pareto Principle, which postulates that 80% of the trouble comes from 20% of the problems80% of the trouble comes from 20% of the problems 48PARETO CHARTPARETO CHARTPareto Charts help breaki
80、ng big problems down to issues with a more manageable size and indentifying the ones who are more relevant.We consider than the “Vital FewVital Few”, i.e. the problems to be addressed in the first place and the “Trivial ManyTrivial Many”, i.e. the ones who are not contributing much. In the process o
81、f continuous improvement, some of the trivial many could become vital few, once we have addressed and improved the original vital many.In short, Pareto Charts:Breaks big problem into smaller piecesIdentifies most significant factorsShows where to focus effortsAllows better use of limited resources49
82、PARETO CHARTPARETO CHARTVertical bar chart presenting defects in order of decreasing occurrence.Helps identify the vital few defects (the 20% that are typically causing 80% of the problem.)“Things that matter most must never be at the mercy of things that matter least.”Johann GoetheType of Furniture
83、 Returns - Store #11 months salesChairsCouchesFine DiningSetsLamps BedsDressers605040302010 0100%80%50%10%50PARETO CHART ExamplePARETO CHART Example51PARETO CHART ExamplePARETO CHART Example52FLOWCHARTSFLOWCHARTSA FlowchartFlowchart, aka Flow DiagramFlow Diagram, is a diagram that uses graphic symbo
84、ls to depict the nature and flow of the steps in a process.During an improvement stage, it helps understanding how the current process works.In short, flowcharts:Promote process understandingProvide tool for trainingIdentify problem areas and improvement opportunitiesDepict customer-supplier relatio
85、nships53FLOWCHART sampleFLOWCHART sample54CAUSE-AND-EFFECT DIAGRAMSCAUSE-AND-EFFECT DIAGRAMSA Cause-and-Effect DiagramCause-and-Effect Diagram is a helps recognize, sort, and exhibit possible causes of a specific problem or quality characteristic. It graphically illustrates the relationship between
86、a given outcome and all the factors that influence the outcome. This type of diagram is sometimes called an Ishikawa diagramIshikawa diagram“ because it was invented by Kaoru Ishikawa, or a fishbone diagramfishbone diagram because of the way it looks.In short, cause-and-effect diagrams:Facilitate fi
87、nding out root causesPromote team involvementUse an methodical, easy-to-read formatPoint out possible causes of variationImprove process knowledgeIdentify areas for data collection55CAUSE-AND-EFFECT DIAGRAMSCAUSE-AND-EFFECT DIAGRAMSEFFECTCAUSE ACAUSE CCAUSE BCAUSE D56CAUSE-AND-EFFECT DIAGRAMSCAUSE-A
88、ND-EFFECT DIAGRAMSHIGH FUEL CONSUMPTIONEQUIPMENTPEOPLEMATERIALSMAIN CATEGORIESMAIN CATEGORIES57CAUSE-AND-EFFECT DIAGRAMSCAUSE-AND-EFFECT DIAGRAMSHIGH FUEL CONSUMPTIONEQUIPMENTPEOPLEMATERIALSTires are not inflated correctlyCarburator needs set-upUse wrong gearDrive too fastPoor maintenanceUse wrong f
89、uelUse wrong oil58CAUSE-AND-EFFECT DIAGRAMSCAUSE-AND-EFFECT DIAGRAMSPEOPLEUse wrong gearDrive too fastPoor maintenanceCant hear engineHearing problemKeep stereo too loud59CHECK SHEETSCHECK SHEETSData are frequently collected using check sheetscheck sheets structured forms designed to collect and org
90、anize data in a systematic way. Each check sheet is used for collecting and recording data referred to a specific process, therefore, it can be designed in a customized way, suitable for the particular process and data set.In short, check sheets:Record data for further analysisProvide historical rec
91、ordIntroduce Data Collection methods60CHECK SHEETSCHECK SHEETSTABULAR FORMAT61CHECK SHEETSCHECK SHEETSXXXXLOCATION FORMAT62SCATTER DIAGRAMSSCATTER DIAGRAMSA Scatter Diagram is a graphical way of representing how two variables are correlated, i.e. how one variable changes with respect to another. The
92、 variables are plotted on axes at right angles to each other and the scatter in the points gives a measure of confidence in any correlation shown.63SCATTER DIAGRAMSSCATTER DIAGRAMSNO CORRELATIONNO CORRELATION64SCATTER DIAGRAMSSCATTER DIAGRAMSWhen one increases, the other increasesPOSITIVE CORRELATIO
93、NPOSITIVE CORRELATION65SCATTER DIAGRAMSSCATTER DIAGRAMSWhen one increases, the other decreasesNEGATIVE CORRELATIONNEGATIVE CORRELATION66SCATTER DIAGRAMSSCATTER DIAGRAMSRelationship fluctuates between positive and negative correlationCURVILINEAR CORRELATIONCURVILINEAR CORRELATION67SCATTER DIAGRAMSSCA
94、TTER DIAGRAMSJust because there appears to be a relationship between variables, it is not necessarily a cause-and-effect relationship!Avoiding Pitfalls:Get a large sample 20 to 25 data pointsInvolve people who understand the processWEAK CORRELATIONWEAK CORRELATIONSTRONG CORRELATIONSTRONG CORRELATION68