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4. Explain the different types of Quality Control Tools withexamples? Howdo Crosby’s absolutes of quality differ from Deming’s principles?
Ans:
-Quality Control (QC) is a system of routine technical activities, to measureand control the quality of the inventory as it is being developed. The QCsystem is designed to:Provide routine and consistent checks to ensure data integrity, correctness,and completeness; Identify and address errors and omissions; Document andarchive inventory material and record all QC activities.
The following seven are considered basic tools for achieving quality.
Flow ChartCheck sheet HistogramPareto AnalysisScatter DiagramControl ChartCause and Effect Diagram
Flow Chart
It is a visual representation of process showing the various steps. It helps inlocating the points at which a problem exists or an improvement is possible.Detailed data can be collected, analyzed and methods for correction can bedeveloped. A sample is shown below lists out the various steps or activities ina particular job. It classifies them as a procedure or a decision. Each decisionpointgenerates alternatives. Criteria and Consequences that go with decision areamenable to evaluation for purposes of assessing quality. The flow charthelps in pin-pointing the exact at which errors have crept in. A simple chart isshown below.
Check Sheet
These are used to record the number of defects, types of defects, locationsat which they are occurring, times at which they are occurring, workmen bywhom they are occurring. It keeps a record of the frequencies of occurrencewith reference to possible defect causing parameter. It helps to implement acorrective procedure at the point where the frequencies are more, so that thebenefit of correct will be maximum. A sample sheet is shown below.
Histogram
Histograms are graphical representations of distribution of data. They aregenerally used to record huge volumes of data about a process. They revealwhether the pattern of distribution – whether there is a single peak, or manypeak and also the extent of variation around the peak value. This helps inidentifying whether the problem is serious. When used in conjunction withcomparable parameters, the visual patterns help us to identify the problemwhich should be attended to.
Pareto Analysis
This is a tool for classifying problem areas according to the degree of importance and attending to the most important. Pareto principle, also called80-20 rule, states that 80 percent of the problems that we encounter ariseout of 20 percent of items. If we find that, in a day, we have 184 assemblieshave given problems and there are 11 possible causes, it is observed that 80per cent of them i.e. 147 of them have been caused by just 2 or 3 of them. Itwill be easy to focus on these 2 or three and reduce the number of defects toa great extent. When the cause of these defects have been attended, we willobserve that some other defect.
Scatter Diagram
These are used when we have two variables and want to know the degree of relationship between them. We can determine if there is cause and effectrelationship between and its extent over a range of values. Sometimes, wecan observe that there is no relationship, in which we can change oneparameter being sure that it has no effect on the other parameter.
Control Charts
These are used to verify whether a process is under control. Variables whenthey remain within a range will render the product maintain thespecifications. This is the quality of conformance. The range of permitteddeviations is determined by design parameters. Samples are taken and themean and range of the variable of each sample (subgroup) is recorded. Themean of the means of the samples gives the control lines. Assuming normaldistribution, we expect 99.97 per cent of all values to lie within the UCL whenwe take 3 standard deviations – Upper Control Limit – and LCL – LowerControl Limit. The graphical representation of data helps in changing settingsto bring back the process closer to the target.
Cause and Effect Diagram.
This is a diagram in which all possible causes are classified on qualitycharacteristics which lead to a defect. These are arranged in such a way thatdifferent branches — the causes are – leading the stem in the direction of thediscovery of the problem. When each of them is investigated thoroughly wewill be able to pinpoint some factors which cause the problem. We will alsoobserve that a few of them will have cumulative effect or even a cascadingeffect.
Deming Wheel
Deming’s approach is summarized in his 14 points. Constancy of purpose forcontinuous improvement Adopt the TQM philosophy for economic purposesDo not depend on inspection to deliver quality Do not award any businessbased on price alone Improve the system of production and serviceconstantly Conduct meaningful training on the job Adopt modern methods of supervision and leadership Remove fear from the minds of everyoneconnected with the organization Remove barriers between departments andpeople Do not exhort, repeat slogans and put up posters.Do not set up numerical quotas and work standards Give pride of workmanship to the workmen Education and training to be given vigorouslyState and exhibit top management’s commitment for quality and productivityUsing the above principles, Deming gave a four step approach to ensure apurposeful journey of TQM. The slope is shown to indicate that if efforts arelet up the program will roll back
Plan
– means that a problem is identified, processes are determinedand relevant theories are checked out.
Do
– means that the plan is implemented on a trial basis. All inputs arecorrectly measured and recorded.Check/Study/Analyze – means that the trials taken according to the plan arein accordance with the expected results. Act – When all the above steps aresatisfactory regular production is started so that quality outcomes areassured.
Crosby’s Absolutes of Quality
Like Deming, he also lays emphasis on top management commitment andresponsibility for designing the system so that defects are not inevitable. Heurged that there be no restriction on spending for achieving quality. In thelong run, maintaining quality is more economical rather than compromisingon its achievement.His absolutes can be listed as under.Quality is conformance to requirements – not ‘goodness’. Prevention, notappraisal, is the path to quality. Quality is measured as the price paid for non-conformance and as indexes. Quality originates in all factions – not qualitydepartment. There are no quality problems people, design, process createproblems.Crosby also has given 14 points similar to those of Deming. Hisapproach emphasizes on measurement of quality, increasing awareness,corrective action, error cause removal and continuously reinforcing thesystem, so that advantages derived are not lost over time. He desires thatthe quality management regimen should improve the overall health of theorganization and prescribed a vaccine.The ingredients are:Integrity – honesty and commitment to produce everything rightfirst time, every time.Communication – Flow of information between departments,suppliers, customers – helps in identifying opportunities.Systems and operations – These should bring in a qualityenvironment – so that nobody is comfortable with anything less thanthe best.
Ans:
-Quality Control (QC) is a system of routine technical activities, to measureand control the quality of the inventory as it is being developed. The QCsystem is designed to:Provide routine and consistent checks to ensure data integrity, correctness,and completeness; Identify and address errors and omissions; Document andarchive inventory material and record all QC activities.
The following seven are considered basic tools for achieving quality.
Flow ChartCheck sheet HistogramPareto AnalysisScatter DiagramControl ChartCause and Effect Diagram
Flow Chart
It is a visual representation of process showing the various steps. It helps inlocating the points at which a problem exists or an improvement is possible.Detailed data can be collected, analyzed and methods for correction can bedeveloped. A sample is shown below lists out the various steps or activities ina particular job. It classifies them as a procedure or a decision. Each decisionpointgenerates alternatives. Criteria and Consequences that go with decision areamenable to evaluation for purposes of assessing quality. The flow charthelps in pin-pointing the exact at which errors have crept in. A simple chart isshown below.
Check Sheet
These are used to record the number of defects, types of defects, locationsat which they are occurring, times at which they are occurring, workmen bywhom they are occurring. It keeps a record of the frequencies of occurrencewith reference to possible defect causing parameter. It helps to implement acorrective procedure at the point where the frequencies are more, so that thebenefit of correct will be maximum. A sample sheet is shown below.
Histogram
Histograms are graphical representations of distribution of data. They aregenerally used to record huge volumes of data about a process. They revealwhether the pattern of distribution – whether there is a single peak, or manypeak and also the extent of variation around the peak value. This helps inidentifying whether the problem is serious. When used in conjunction withcomparable parameters, the visual patterns help us to identify the problemwhich should be attended to.
Pareto Analysis
This is a tool for classifying problem areas according to the degree of importance and attending to the most important. Pareto principle, also called80-20 rule, states that 80 percent of the problems that we encounter ariseout of 20 percent of items. If we find that, in a day, we have 184 assemblieshave given problems and there are 11 possible causes, it is observed that 80per cent of them i.e. 147 of them have been caused by just 2 or 3 of them. Itwill be easy to focus on these 2 or three and reduce the number of defects toa great extent. When the cause of these defects have been attended, we willobserve that some other defect.
Scatter Diagram
These are used when we have two variables and want to know the degree of relationship between them. We can determine if there is cause and effectrelationship between and its extent over a range of values. Sometimes, wecan observe that there is no relationship, in which we can change oneparameter being sure that it has no effect on the other parameter.
Control Charts
These are used to verify whether a process is under control. Variables whenthey remain within a range will render the product maintain thespecifications. This is the quality of conformance. The range of permitteddeviations is determined by design parameters. Samples are taken and themean and range of the variable of each sample (subgroup) is recorded. Themean of the means of the samples gives the control lines. Assuming normaldistribution, we expect 99.97 per cent of all values to lie within the UCL whenwe take 3 standard deviations – Upper Control Limit – and LCL – LowerControl Limit. The graphical representation of data helps in changing settingsto bring back the process closer to the target.
Cause and Effect Diagram.
This is a diagram in which all possible causes are classified on qualitycharacteristics which lead to a defect. These are arranged in such a way thatdifferent branches — the causes are – leading the stem in the direction of thediscovery of the problem. When each of them is investigated thoroughly wewill be able to pinpoint some factors which cause the problem. We will alsoobserve that a few of them will have cumulative effect or even a cascadingeffect.
Deming Wheel
Deming’s approach is summarized in his 14 points. Constancy of purpose forcontinuous improvement Adopt the TQM philosophy for economic purposesDo not depend on inspection to deliver quality Do not award any businessbased on price alone Improve the system of production and serviceconstantly Conduct meaningful training on the job Adopt modern methods of supervision and leadership Remove fear from the minds of everyoneconnected with the organization Remove barriers between departments andpeople Do not exhort, repeat slogans and put up posters.Do not set up numerical quotas and work standards Give pride of workmanship to the workmen Education and training to be given vigorouslyState and exhibit top management’s commitment for quality and productivityUsing the above principles, Deming gave a four step approach to ensure apurposeful journey of TQM. The slope is shown to indicate that if efforts arelet up the program will roll back
Plan
– means that a problem is identified, processes are determinedand relevant theories are checked out.
Do
– means that the plan is implemented on a trial basis. All inputs arecorrectly measured and recorded.Check/Study/Analyze – means that the trials taken according to the plan arein accordance with the expected results. Act – When all the above steps aresatisfactory regular production is started so that quality outcomes areassured.
Crosby’s Absolutes of Quality
Like Deming, he also lays emphasis on top management commitment andresponsibility for designing the system so that defects are not inevitable. Heurged that there be no restriction on spending for achieving quality. In thelong run, maintaining quality is more economical rather than compromisingon its achievement.His absolutes can be listed as under.Quality is conformance to requirements – not ‘goodness’. Prevention, notappraisal, is the path to quality. Quality is measured as the price paid for non-conformance and as indexes. Quality originates in all factions – not qualitydepartment. There are no quality problems people, design, process createproblems.Crosby also has given 14 points similar to those of Deming. Hisapproach emphasizes on measurement of quality, increasing awareness,corrective action, error cause removal and continuously reinforcing thesystem, so that advantages derived are not lost over time. He desires thatthe quality management regimen should improve the overall health of theorganization and prescribed a vaccine.The ingredients are:Integrity – honesty and commitment to produce everything rightfirst time, every time.Communication – Flow of information between departments,suppliers, customers – helps in identifying opportunities.Systems and operations – These should bring in a qualityenvironment – so that nobody is comfortable with anything less thanthe best.
