This document discusses military standards for acceptance sampling, including Military Standard 105E and Military Standard 414. MIL STD 105E provides sampling schemes for attributes data using single, double, or multiple sampling plans. It describes normal, tightened, and reduced inspection levels based on a vendor's quality history. MIL STD 414 provides variables acceptance sampling plans that use sample sizes based on lot size and inspection level, assuming the quality characteristic is normally distributed. It includes plans based on sample standard deviation, range, and known process standard deviation. The document provides examples of using these standards to determine acceptance sampling plans.

1. MILITARY STANDARDS
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Military Standard 105E
 Most widely used acceptance sampling system for attributes
 MIL STD 105E is Acceptance Sampling System
 collection of sampling schemes
 Can be used with single, double or multiple sampling plans
 We will consider single sampling plans for this course

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Inspection Types
 Normal Inspection
 Used at start of inspection activity
 Tightened Inspection
 Instituted when vendor’s recent quality history has deteriorated
 Acceptance requirements for lots are more stringent
 Reduced Inspection
 Instituted when vendor’s recent quality history has been exceptionally
good
 Sample size is usually smaller than under normal inspection

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Switching Rules
- Production Steady
- 10 consecutive lots accepted
- Approved by responsible
authority
NormalReduced Tightened
- Lot rejected
- Irregular production
- Lot meets neither accept
nor reject criteria
- Other conditions warrant
return to normal inspection
2 out of 5 consecutive lots
rejected
5 consecutive
lots accepted
10 consecutive lots remain
on tightened inspection
Start
Discontinue
Inspection
AND conditions
OR conditions

5. Procedure for MIL STD 105E
 Choose AQL
 Choose the inspection level
 Determine the lot size
 Find the appropriate sample code size letter from table A-1.
 Determine the appropriate type of sampling plan to use.
 Enter appropriate table to find the type of plan to be used.
 Determine the corresponding normal and reduced inspection
plans to be used when required.
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Example
 Suppose product comes from vendor in lots of size 2000
units. The acceptable quality level is 0.65%. Determine the
MIL STD 105E acceptance-sampling system.

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Normal Insp. Level
Lot Size
= 2000

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AQL
Plan K
Sample 125 units.
Ac = 2, accept if defects ≤ 2.
Re = 3, reject entire lot if defects ≥ 3.

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AQL
Plan K
Sample 125 units
Ac = 1, accept if defects ≤ 1.
Re = 2, reject entire lot if defects ≥ 2.

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Sample 50 units
Ac = 1, accept if defects ≤ 1.
Re = 3, reject entire lot if defects ≥ 3.
AQL
Plan K

11. Military Standard 414
 MIL STD 414 is a lot-by-lot acceptance-sampling
plan for variables introduced in 1957.
 Sample sizes are a function of the lot size and
the inspection level.
 All sampling plans assume the quality
characteristic of interest is normally distributed.
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12. Military Standard 414
 MIL STD 414 is divided into four sections:
 A: general description of the sampling plans including
definitions, sample size code letters, and OC curves
for the plans.
 B: variables sampling plans based on the sample
standard deviation for the case in which the process or
lot variability is unknown.
 C: variables sampling plans based on the sample
range method
 D: variables sampling plans for the case where the
process standard deviation is known.
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14. Procedure 1 (k-Method)
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15. Procedure 2 (M-Method)
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16. Double specification limit variability
unknown
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17. Example
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18. Range method for variability
unknown
 If mentioned in the question then we will go for
this method.
 In this method all the steps are same as we have
done before only difference is instead of
calculating standard deviation we will calculate
range.
 The table used in this method is C1 or C2 and C3
or C4.
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19. Thank You
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