QUALITY CONTROL AND QUALITY MEASURE

1. Quality Control And
Control Charts

2. QUALITY CONTROL
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3. Definition
Present era is the ‘Era of Quality'. In this age of
cutthroat competition and large-scale
production, only that manufacturer can
survive who supplies better quality goods and
renders service to-the consumers. In fact,
quality control has become major
consideration before establishing an industrial
undertaking. Proper quality control ensures
most effective utilization of available
resources and reduction in cost of production
The word quality control comprises of two
words viz., quality and control. It would be
appropriate to explain these two words
separately to understand clearly the meaning of
quality control.
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4. “
“Quality control means the
recognition and removal of
identifiable causes and defects, and
variables from the set standards”.
by Alford and Beatty
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5. oTo establish the desired quality standards which are acceptable to the customers
oTo discover flaws or variations in the raw materials and the manufacturing processes in
order to ensure smooth and uninterrupted production.
oTo evaluate the methods and processes of production and suggest further improvements
in their functioning
oTo study and determine the extent of quality deviation in a product during the
manufacturing process
oTo analyze in detail the causes responsible for such deviation.
oTo undertake such steps which are helpful in achieving the desired quality of the product
OBJECTIVE
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6. Need For Quality
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Increase productivity Reduce cost of repairs
Increase loyal customer base Butter profits

7. Attribute
◉ A product characteristic
that can be evaluate with
a discrete response
◉ Good –bad , yes – no
Quality measures
Variable
◉ A product characteristic
that is continuous can be
measured
◉ Weight - length
.
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8. Technique of quality control
Inspection
Statistical
quality
control
(SQC)
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9. Control charts
one type of quality control
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10. What is control chart
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The control chart is a graph used to study how a process changes over time.
Data are plotted in time order. A control chart always has a central line for
the average, an upper line for the upper control limit, and a lower line for the
lower control limit. These lines are determined from historical data. By
comparing current data to these lines, you can draw conclusions about
whether the process variation is consistent (in control) or is unpredictable
(out of control, affected by special causes of variation).
The control charts of variables can be classified based on the statistics of
subgroup summary plotted on the chart.
o X chart
o P Chart
o S Chart

11. X-Charts present variable data. Each data point is the statistical mean of a
subgroup of values.
The statistical principles used in calculating the UCL and LCL are based on
normal distribution. By default, UCL and LCL are calculated at three standard
deviations from the mean. However, these values can be adjusted on the Graph
Options dialog box, Statistics tab.
X- chart
UCL : UPPER CONTROL LIMIT LCL: LOWER CONTROL LIMIT 11

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13. P-Charts are used for data that is counted. Each data point is a ratio of
its own discrete sample set. P-Charts can display fraction nonconforming
or percent nonconforming data values. The statistical principles used in
calculating the UCL and LCL are based on binomial distribution
.
P- chart
UCL : UPPER CONTROL LIMIT LCL: LOWER CONTROL LIMIT 13

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15. An S-chart is a type of control chart used to monitor the process
variability (as the standard deviation) when measuring subgroups (n ≥
5) at regular intervals from a process. Each point on the chart represents
the value of a subgroup standard deviation. The center line for each
subgroup is the expected value of the standard deviation statistic. Note
that the center line varies when the subgroup sizes are unequal..
S - chart
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17. Submitted to :
Mr. Rishabh pare
Thanks!
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Submitted by :
Aman Raj
Kshama Bhandari
Vipin Manikpuri
Yuvraj Singh Parihar
(BBA in Aviation
4th semester)