Assignment title: Information
ASSIGNMENT III
Question 1
Consider the ChSP-1 plan and obtain the relative slope at the unity Indifference Quality Level
(IQL, np0) using the definition
h dlogPa
dlogp
2dPa
0 dnp
p p0 p np0
.
Obtain the parameters of the 'matching' single sampling plans using the empirical relationship
2
h
20
= n
sp0 + 0.06 = Ac + 0.73
where n
s is the sample size of the matching single sampling plan with fractional acceptance
number. Provide a comparison of single and chain sampling plans using the unity sample sizes np0
and n
sp0.
Question 2
Zero acceptance number single sampling plans require the minimum sample size for a given one
point on the operating characteristic curve when compared to single (Ac 1), double and multiple
sampling plans. This question requires you to employ it as a 'reference sampling plan' in the
Skip-lot sampling plan SkSP-2 of Perry (1973a; reproduced in the Book of Readings).
Explore the advantages of using zero acceptance number plan as a reference plan in a SkSP-2
system. Draw few OC curves of the SkSP-2 scheme assuming any reasonable plan parametric
values. That is, consider two or three combinations of i, f and n and draw the OC curves of the zero
acceptance number and SkSP-2 plans. What advantages are seen in employing the zero acceptance
number plan as a reference sampling plan?
Based on the observations made on the behaviour of the SkSP-2 OC function, develop a procedure
for designing a SkSP-2 plan with a zero acceptance number reference plan for given values of p1,
p2, and . In your answer, you may provide a Table of unity values or simply indicate how a
search procedure based on the properties of the OC function can be developed.
What are the limitations of a SkSP-2 plan having a zero acceptance number reference plan?
Discuss.Question 3
CSP-1 continuous sampling plan requires 100% inspection to be performed when required and
hence the AOQL is the suitable index for designing. Explain how you may proceed to find the
AOQL of a given CSP-1 plan. Your answer may be deriving an expression for AOQL in terms the
parameters i and f or writing a suitable computer program to compute the AOQL for given i and f.
You should include a numerical example to illustrate the computation of AOQL.
Question 4
Given AQL = 0.5% and LQL = 2%. Assume that these quality levels are not associated with any
given values of and but it is desired that the risks are kept as small as possible. For
administrative reasons, the sample size is fixed as 200. Derive a formula for the acceptance number
of the single sampling plan which minimises the sum of producer's and consumer's risks namely
1-P
a(p1)+ Pa(p2) assuming binomial distribution for OC curve. Verify your result numerically.
What are the advantages with this designing approach?
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