write what symbol indicates
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Within each symbol, write down what the
symbol represents.
This could be the start or finish of the process,
the action to be taken, or the decision to be
made.
Symbols are connected one to the other by
arrows, showing the flow of the process.
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Points to note
Flow charts are simple diagrams that map out a process
so that it can easily be communicated to other people.
To draw a flowchart, brainstorm the tasks and decisions
made during a process, and write them down in order. Then map these out in flow chart format using
appropriate symbols for the start and end of a process,
for actions to be taken and for decisions to be made.
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Finally, challenge your flow chart to make sure
that its an accurate representation of the
process, and that that it represents the most
efficient way of doing the job
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3. Check sheets
The intent and purpose of collecting data is to either
control the production process, to see the relationship
between cause-and-effect, or for the continuous
improvement of those processes that produce any type
of defect or nonconforming product.
A Check Sheet is used for the purpose of collecting data
to compile in such a way as to be easily used, understood
and analyzed automatically.
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The Check Sheet, as it is being completed,
actually becomes a graphical representation
of the data you are collecting, thus you do
NOT need any computer software, or
spreadsheet to record the data.
It can be simply done with pencil and paper
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The main functions - Checks
Production process distribution checks -
where the distribution lies.
Defective item checks - to determine what
kind of defects exist in the process.
Defect location checks - to determine where
the common defects on a part are located.
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Defective cause checks - type of defect and
thus validate the cause thereof.
Check-up confirmation checks - final phase of
assembly to check the finished product or
work.
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4. Histograms
The common person believes that if a part is made in
mass production from a machine, all of the parts will be
exactly alike.
The truth is that even with the best of machines and processes, no
two parts are exactly the same.
The product will have a main or "mean" specification limit, with
plus/minus tolerance that states that as long as the part is
produced within this range, to that range, it is an acceptable part.
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The object is to hit the target specification, however, that
is not always totally possible.
The purpose of a Histogram is to take the data that is
collected from a process and then display it graphically toview how the distribution of the data, centers itself
around the mean, or main specification.
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The histogram will graphically show
The center of the data.
The spread of the data.
Any data skewness (slant, bias or run at anangle).
The presence of outliers (product outside the
specification range).
The presence of multiple modes (or peaks)
within the data.
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5. Scatter diagrams
The Scatter Diagram is another Quality Tool that can beused to show the relationship between "paired data",and can provide more useful information about aproduction process.
What is meant by "paired data"?
The term "cause-and-effect" relationship between twokinds of data may also refer to a relationship betweenone cause and another, or between one cause and
several others.
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For example, you could consider the relationshipbetween an ingredient and the product hardness;between the cutting speed of a blade and the variationsobserved in length of parts; or the relationship between
the illumination levels on the production floor and themistakes made in quality inspection of product produced.
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6. Control charts
Control charts are generally used in a
production or manufacturing environment
and are used to control, monitor and
IMPROVE a process.
Common causes are always present and
generally attributed to machines, material and
time vs. temperature.
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This normally takes a minor adjustment to the process to
make the correction and return the process to a normal
output.
However, when making a change to the process, it should always be
a MINOR change.
If a plot is observed that shows a slight deviation trend
upward or downward, the "tweaking" adjustment should
be a slight change, and then another observation should
be made.
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Too often people will over-correct by making
too big of an adjustment which then causes
the process to dramatically shift in the other
direction.
For that reason, all changes to the process
should be SLIGHT and GRADUAL!
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Control Lines
A control chart is a graph or chart with limit
lines, called control lines.
There are basically three kinds of control lines:
the upper control limit (UCL),
the central line (actual nominal size of
product),
the lower control limit (LCL).
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The Xbar & R Control Chart
An Xbar & R Control Chart is one that shows both
the mean value ( X ), and the range ( R ).
The Xbar portion of the chart mainly shows any
changes in the mean value of the process, while
the R portion shows any changes in the dispersion
of the process.
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This chart is particularly useful in that it shows
changes in mean value and dispersion of the
process at the same time, making it a very effective
method for checking abnormalities within theprocess; and if charted while in progress, also
points out a problem in the production flow in real
time mode.
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7. Fishbone diagram
Cause & Effect Diagrams
Identifying the Likely Causes of Problems
Also called Fish or Fishbone Diagram andIshikawa Diagrams
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Cause and Effect analysis helps you to think
through causes of a problem thoroughly.
Their major benefit is that they push you to
consider all possible causes of the problem,
rather than just the ones that are most
obvious
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Conclusion.
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