This presentation gives a basic idea about application of double and multi sampling methods with application.

1. DOUBLE AND MULTI SAMPLING PLAN
Presented
By
Hiran Gabriel D J
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2. Sampling
Sampling is the act, process, or technique of selecting a
suitable sample, or a representative part of a population for the
purpose of determining parameters or characteristics of the
whole population.
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3. Double
sampling
Defined by four parameters:
n1 = sample size of first sample.
c1 = acceptance number of first sample.
n2 = sample size of first sample.
c2 = acceptance number of first sample.
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4. Process flow
chart
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5. Conditions for double sampling plan
One sample is
drawn initially.
If number of
defectives is less
than or equal to
some lower
rejection value lot is
accepted.
If not the lot is
rejected.
Then a second
larger sample is
drawn.
Lot is either
accepted or rejected
based on the given
data.
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6. Design of
Double
sampling plan
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7. Advantages and disadvantages
Advantages
• Reduces total number of rejections.
• Gives a second chance for vendor.
Disadvantages
• Can loose economical advantage.
• Customer is at risk.
• More record keeping.
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8. Case study
A bearing cap has been evaluated by double acceptance
sampling techniques in a bakery machines manufacturing company
in turkey.
Software used
WinQSB acceptance sampling module
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9. Design of
experiment
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10. Results
obtained
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11. Sampling
parameters
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12. Graphs
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13. Multiple sampling plan
Multiple sampling is an extension of double sampling.
It involves inspection of 1 to successive samples as required to reach
an ultimate decision.
Multiple sampling plans are usually presented in tabular form.
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14. Merits
• It is very flexible as compared to other methods of sampling.
• It leads to administrative efficiency by permitting the field work to be
concentrated and yet covering a large area.
• It is of great utility in surveys of undeveloped areas where no up to-date and
accurate frame is available for subdivision of the materials into reasonably small
sample units.
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15. Demerits
• It is likely to cause many errors as it involves a process of divisions
and sub-divisions of the various strata or clusters in different stages.
• It leads to greater variability of the estimates than any other method of
sampling,
• In general, it is less efficient than a suitable single stage random
sampling.
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16. Reference
An Application of Single and Double Acceptance Sampling Plans for a
Manufacturing System Erdal AYDEMIR, Mehmet Onur OLGUN
Suleyman Demirel University, Engineering and Architecture Faculty,
Industrial Engineering Department, Isparta, Turkey
eaydemir@mmf.sdu.edu.tr , onurolgun@mmf.sdu.edu.tr