36-37Urbano & Uy
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Transcript of 36-37Urbano & Uy
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Quality Monitoring toolsControl ChartRadar Chart
Histogram
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Objectives:
To be able to enumerate and discusswhat are the quality monitoring tools.
To be able to define what are control
chart, histogram, and radar charts; whouses it, when to use it and how to use it.
To be able to explain the differences ofcontrol chart, histogram, and radarchart.
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Introduction
Most of the organizations use quality toolsfor various purposes related to controllingand assuring quality.
Although there are a good number of
quality tools specific to certain domains,fields, and practices, some of the qualitytools can be used across such domains.
These quality tools are quite generic and canbe applied to any condition.Control chart, radar chart and histogram
are some quality monitoring tools used in
organizations. These tools can provide much
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Control charts statistical tools used toanalyze and understand process,
variables, to determine the processscapability to perform with respect tothose variables, and to monitor the
effect of those variables betweencustomer needs and processperformance.
A Control Chart is a tool you can useto monitor a process. It graphicallydepicts the average value and the
upper and lower control limits (the
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Who uses it?
The management, the team.
Why use it?
All processes have some form ofvariation. A Control Chart helps youdistinguish between normal and
unusual variation in a process. If youwant to reduce the amount ofvariation in a process, you need to
compare the results of the process
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Variation can exist for tworeasons:
1. Common causes are flawsinherent in the design of theprocess.
2. Special causes are variationsfrom standards caused byemployees or by unusualcircumstances or events.
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Most variations in processes are
caused by flaws in the system or theprocess, not by the employees. Onceyou realize this, you can stop blamingthe employees and start changing thesystems and processes that cause theemployees to make mistakes. (It isimportant to remember, however,
that some variations are not"mistakes" introduced by employees,but, rather, they areinnovations.
Some variations are
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When to use it?First, you need to define the
standards of how things should be. Then,you need to monitor (collect data) aboutprocesses in your organization. Then, youcreate a control graph using the monitoringdata.
How to use it:1. Select the process to be charted and
decide on the type of control chart to
use.. Use a Percent Nonconforming Chart if
you have data measured using twooutcomes (for example, the billing can be
correct or incorrect)..
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2. Determine your sampling method and
plan: Choose the sample size (how manysamples will you obtain?).
Choose the frequency of sampling,
depending on the process to beevaluated (months, days, years?). Make sure you get samples at random
(don't always get data from the same
person, on the same day of the week,etc.).
3. Start data collection:
Gather the sampled data.
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4. Calculate the appropriate statistics (the controllimits) depending on the type of graph.
5. Observation:The control graph is divided into zones:______________________________ Upper Control Limit
(UCL)
______________________________ Standard (average)
______________________________ Lower Control Limit(LCL)
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6. Interpret the graph: If the data fluctuates within the
limits, it is the result of commoncauses within the process (flawsinherent in the process) and can
only be affected if the system isimproved or changed.
If the data falls outside of the limits,
it is the result of special causes (inhuman service organizations,special causes can include badinstruction, lack of training,ineffective processes, or
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These special causes must beeliminated before the control chart
can be used as a monitoring tool.In a health setting, for example,staff may need better instructionor training, or processes may need
to be improved, before the processis "under control." Once theprocess is "under control," samplescan be taken at regular intervals toassure that the process does notfundamentally change.
A process is said to be "out ofcontrol" if one or more points fallsoutside the control limits.
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A radar chart graphically shows the sizeof the gaps among five to ten
organizational performance areas. Thechart displays the important categories ofperformance and makes visibleconcentrations of strengths and
weaknesses.
When to use it:
A radar chart shows how a team hasevaluated a number of organizationalperformance areas. It is thereforeessential that the initial evaluation includevaried perspectives to provide an overall
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How to use it:
Create categories. Use headers from anaffinity diagram or brainstorm majorcategories of organizational performance tobe plotted. A radar chart can normally
include five to ten categories.
Standardize performance definitions.Have all evaluators agree to usestandardized definitions of both fullperformance and non-performance in eachcategory so that ratings are performed
consistently. Define the scoring range
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Rate each performancecategory. Each evaluator rateseach category individually, andthe team then develops anaverage or consensus score for
each category. Alternatively, theteam as a whole may initiallydevelop an average or consensus
score for each category.
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Construct the chart.
1. Draw a large circle and insert as manyspokes or radii as there are performancecategories.
1. Around the perimeter of the circle, label each
spoke with the title of a performancecategory.
1. Subdivide each spoke into the number of
increments established in the rating scale.Label the center of the circle where spokesjoin as 0 (no performance) and place the
highest rating number (full or exceptionalperformance) at the end of the spoke at theouter ring. (You may want to draw additional
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Plot the ratings. For each performancecategory, plot on the chart the associatedrating. Then connect the plotted points onall the spokes. Highlight the enclosed
central shape as necessary for ease inviewing.
Interpret and use the results. The resulting
radar chart will graphically show areas ofrelative strength and relative weakness, aswell as depicting general overallperformance.
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Radar/Spider ChartExample
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The histogram can be helpful in
estimating process capability.Alternatively, a stem-and-leaf diagrammay be substituted for the histogram. Atleast 100 or more observations shouldbe available for the histogram (or thestem-and-leaf diagram) to bemoderately stable so that a reasonably
reliable estimate of process capabilitymay be obtained. An advantage of usingthe histogram to estimate processcapability is that it gives an immediate,
visual impression of process
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Why use it?
Measure numerical quantities asopposed to categorical classifications. Theytypically examine intervals rather thansingle numbers, although either type ofvalue is acceptable for histograms. Thesecond key component of a histogram is anatural order of values; the variables must
be plotted and graphed in a certainsequence. For example, graphing the agerange 18-35 adjacent to 65+ would makelittle sense and could create a misleading
or confusing representation of data.
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Appearance
The x-axis of a histogram contains aset of numerical values, which areusually intervals; some possibilitiesare age ranges, rainfall amounts or
height intervals. The y-axis showsthe scale by which the chosennumerical value is being measured.
For example, to graph the numberof people in a group in certain ageranges, plot the age ranges on thex-axis and the number of people onthe -axis. The bars of a histo ram
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Applications
Histograms organize distributions ofdata into an easily understoodgraphical form. Their primary use is
showing how often different sets ofvariables occur, and they help you tellat a glance which variable occursmost frequently. Additionally,
histograms can reveal whether thefrequency of variables is evenlydistributed or skewed to one side ofthe graph because the numericalvalues must be plotted in order.
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Differences of the charts
Histogram is used for illustrating thefrequency and the extent in the context oftwo variables. Chart with columns. Thisrepresents the distribution by mean.
Control chart is the best tool for monitoringthe performance of a process. used formonitoring any processes related to
function of the organization.
Radar charts are useful when you want tolook at several different factors all related
to one item. Radar charts have multiple
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Lesson learned
In this study, we are able toenumerate and discuss what arethe quality monitoring tools. We
are also able to define what arecontrol chart, histogram, andradar charts; who uses it, when
to use it, how to use it and theirdifferences.
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Click to edit Master subtitle style
Bibliography:Books:Montgomery, Douglas, C.,(2001).Introduction to Statistical QualityControl Using the Histogram;John Wiley & sons, Inc., p352
Gitlow, Howard, S., Oppenheim, Alan, J., Oppenheim, Rosa.,Levine, David, M.(3rd edition). Quality management The structureof control charts; Mcgraw-Hill companies, Inc., p150
Electronic Resources:http://www.tutorialspoint.com/.07-07-12
http://erc.msh.org.07-07-12
http://www.ehow.com.07-07-12
http://erc.msh.org.07-07-12/http://www.tutorialspoint.com/.07-07-12http://erc.msh.org.07-07-12/http://erc.msh.org.07-07-12/http://erc.msh.org.07-07-12/http://www.tutorialspoint.com/.07-07-12http://www.tutorialspoint.com/.07-07-12