SJ 20712-1998 Count inspection single-level and multi-level continuous sampling inspection procedures and tables
Some standard content:
Military Standard of the Electronic Industry of the People's Republic of China FL0110
SJ 20712—1998
Single-and multi-level continuous sampling procedures and tables for inspection by counting inspection
Single-and multi-level continuous sampling procedures and tables for inspection by counting inspection attributes1998-03-18 Release
1998-05-01 Implementation
Before approval by the Ministry of Electronics Industry of the People's Republic of China
1. This standard is equivalent to the US military standard MIL-STD-1235C-1988 "Counting Inspection Single-level and Multi-level Continuous Sampling Inspection Procedures and Tables", and its format and sequence are compiled in accordance with the "Interim Regulations on the Compilation of National Military Standards" issued by the National Defense Science and Technology Commission in March 1990. 2. The procedures and tables provided in this standard are for the application of counting inspection continuous sampling inspection plans. The characteristics and interrelationships of these continuous sampling inspection plans are as follows: a. CSP-1 type is a single-level continuous throwing inspection plan, which stipulates that the 100% inspection procedure and the shooting inspection procedure are alternately carried out:
b. C SP--F type continuous sampling inspection scheme is suitable for relatively short unit product series. It is a special type of CSP-1 type continuous sampling inspection scheme, so it allows the use of a smaller number of consecutive qualified products: C. CSP-2 type is a modified continuous sampling inspection scheme of CSP1 type, in which only when there are two unqualified products not exceeding the specified number of consecutive qualified sample units will it return to 100% inspection. D. CSPT type is a multi-level continuous sampling inspection scheme. When the product quality is confirmed to be excellent, this type of continuous sampling inspection scheme stipulates a reduction in the frequency of sample inspections: e. CSP-V type is also a single-level continuous sampling inspection scheme. When the product quality is confirmed to be excellent, this type of continuous sampling inspection scheme stipulates a reduction in the number of consecutive qualified products. When there is no economic value in reducing the sampling inspection frequency, CSP-V type is different from CSP Type -T is another optional continuous sampling inspection plan. For details of the above five different types of continuous sampling inspection plans, see Chapter 5 of this standard. 3. The main differences between this standard and MIL STD--1235C-1988 are as follows: a. This standard provides the method of drawing the function curve of CSP-1 type, CSP-2 type, CSP-T type and CSP-V type continuous sampling inspection plans in Appendix A, Appendix B, Appendix C and Appendix D respectively; while MIL-STD-1235C-1988 directly provides the function curve of CSP-1 type, CSP-2 type, CSP-T type and CSP-V type continuous sampling inspection plans in Appendix A, Appendix B, Appendix C and Appendix D respectively; b. This standard uses .1. of MIL-STD-1235C-1988 as the 100 series of items All contents were moved to Section 5 and rewritten in accordance with the first chapter "Appendix A: Example of Hierarchical Writing of Standards and Guidance Technical Documents (Supplement)" of the "Interim Regulations on the Writing of National Military Standards" issued by the Second National Defense Science and Technology Commission in March 1990: c. This standard defines the terms, abbreviations and symbols in Chapter 3 of MIL-STD-1235C-1988 separately, and renumbers them according to the position and mutual relationship of the terms in the conceptual system. In addition, the two commonly used terms "sample unit" and "sample" are added to the appropriate positions. 4. MIL-STD--1235C-1988 does not give the functional curves of the CSP--F type continuous sampling inspection plan. Since no accurate method has been developed to determine them, this standard does not give the method for drawing the functional curve of the CSP--F type continuous sampling inspection plan.
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Subject content
Scope of application
Application guide
Referenced documents
Abbreviations:
General requirements
Classification of defects and nonconforming products…
Qualified quality level,
Average inspection quality…
Submit unit products
Acceptance and rejection
Taking samples|| tt||Continuous sampling inspection plan
Suspend acceptance
Estimate process average
Draw functional sampling line
Average inspection quality curve
Average inspection ratio curve
4.13 Sampling inspection characteristic curve
Detailed requirements
5.1CSP-1 type continuous sampling inspection plan
5.2CSP-F type reverse sampling inspection plan
5. 3CSP-2 type continuous sampling inspection plan
5.4CSP-T type continuous sampling inspection plan
5.5CSP-V type continuous sampling inspection plan
Notes
6.1 Intended use...
6.2 Subject terminology
Appendix Method for drawing function curves for ACSP-1 type continuous sampling inspection plan (reference)Appendix Method for drawing function curves for BCSP-2 type continuous sampling inspection plan (reference)Appendix Method for drawing function curves for CCSP-T type continuous drag sampling inspection plan (reference)Appendix Method for drawing function curves for DCSP-V type continuous sampling inspection plan (reference)iikAoNirkAca
1 Scope
People's Republic of China Electronic Industry Military Standard Counting Inspection Single-level and Multi-level Continuous
Sampling Inspection Procedures and Tables
Singleand multi-level continuous sampling procedures and tables for inspection by attributes1.1 Subject content
SJ 20712-1998
This standard specifies different types of continuous sampling inspection programs for counting inspection, namely CSP-1, CSP-F, CSP2, CSP-T, and CSP-V, and provides corresponding operation procedures and related parameter tables for them.
In addition, this standard also provides the method of drawing function curves for the other four types of continuous sampling inspection programs except CSP-F, as well as the explanation and use of these curves. 1.2 Scope of application
This standard is applicable to the inspection of mobile unit products. 1.3 Application guidelines
Before using the continuous sampling inspection program specified in this standard, the following conditions must be met: a. It is a mobile unit product (see Article 3.1.2) b. When required, it is possible to quickly conduct self-checking. There should be sufficient space, equipment and relevant personnel at or near the inspection site;
C. The inspection is quick and relatively easy:
d. The quality of the process and raw materials is stable (see 5.1.2.2a, 5.2.2.2a, 5.3.2.2a, 5.4.2.2a and 5.5.2.2a);
e. The inspection is non-destructive.
For various physical objects , such as finished products, components, raw materials, data (records) and any other entities, as long as they meet the above-mentioned conditions, can use the continuous sampling inspection plan specified in this standard, but are not limited to the continuous sampling inspection plan specified in this standard. According to the instructions provided by this standard for the use of functional lines, the most appropriate type of continuous sampling should be determined in accordance with this standard. Ministry of Electronics Industry of the People's Republic of China 1998-03-18 Issued 1998-05-01 Implementation
SJ 20712—1998
This standard can be used as a reference for the inspection plan. This standard reserves the right to approve the use of a certain type of continuous inspection plan for the ordering party.
When this standard is cited in specifications, contracts, inspection procedures or similar documents, the application of the continuous sampling plan shall be carried out in accordance with the provisions of this standard. Unless otherwise specified in the above-mentioned referenced documents, the provisions of this standard shall be completed by the contractor.
2 Referenced documents
No pump document in this chapter
3 Definitions
3.1 Terminology
3.t.1 Unit of product
The basic unit for the purpose of continuous sampling inspection is called unit product. It can be a single product, a pair of products, a group of products, a certain length, a certain area, a certain volume, a certain weight, and a final product component or final product. It can be the same as or different from the unit product of procurement, sales, production and transportation.
3.1.2 Moving product Unit products that flow through the inspection station are called moving product units. Typically, they flow through the inspection station on a conveyor belt or assembly line. Unit products can also be moved through the inspection station by hand, push or other transport tools.
3.1.3 Sample unit sampleunit
A unit product randomly selected from the unit products that flow through the inspection station for inspection is called a sample unit. 3.1.4 Sample1 sample
The entirety of the sample units is called a sample.
3.1.5 Conforming unit
A unit product that meets all the specified requirements with respect to the characteristics being considered is called a conforming product. 3.1.6 Defect
A unit product with specified requirements that does not meet any of the requirements is called a defect. 3.1.7 Defect concerned Defect concerned Defects that are listed in the inspection station and are detected by the continuous sampling inspection plan are called concerned defects 3.1.8 Critical defect Critical defect A defect that, according to experience and judgment, will cause a hazard to people who use, protect or rely on the product independently or cause an unsafe situation Adoption Note: They are added to this standard. 12 TKAoNrKAca-SJ 20712—1998 A defect that, according to experience and judgment, will hinder the completion of a tactical mission for an important final product (for example: ships, aircraft, tanks, missiles or air vehicles) is called a fatal defect. 3.1.9 Major defect Major defect A non-fatal defect that will cause a failure for the intended purpose or greatly reduce the actual performance of the unit product is called a major defect.
3.1.10 Minor defect
A defect that does not significantly reduce the actual performance of the unit product for the intended purpose; or a defect that deviates from the standard and has almost no effect on effective use and operation is called a minor defect. 3.1.11 Defective
A unit product with one or more defects is called a defective product. 3.1.12 Critical defectiveA unit product with one or more critical defects and possibly major and/or minor defects is called a critical defective.
3.1.13 Major defectiveA unit product with one or more major defects and possibly minor defects but no fatal defects is called a major defective.
3.1.14 Minor defectiveA unit product with one or more minor defects and no fatal defects and no major defects is called a minor defective.
3.1.15 Inspection
The process of comparing the unit product with the specified requirements by measurement, test or other methods is called inspection. 3.1. 16 Inspection by attributesThe process of determining whether a unit product is qualified or unqualified or calculating the number of defects of a unit product based on the inspection of the characteristics contained in the unit product is called inspection by attributes. 3.1.17 One hundred percenl inspection Checking each unit product according to the relevant defects listed by the inspection station, and eliminating all the unqualified products found is called one hundred percenl inspection. Synonyms: screening 3.1.18 Clearance number The number of continuous qualified products relative to the number of continuous qualified products required by the one hundred percenl inspection measure is the number of continuous qualified products. 3.1.19 Checking inspection To determine the effectiveness of one hundred percenl inspection, the unit product that has undergone one hundred percenl inspection is inspected by the contractor. This is called checking inspection. 3 SJ 20712—1998 3.1.20 Sampling inspection Sampling inspection The method of checking the relevant defects of unit products by random sampling at the inspection station is called sampling inspection. 3.1.21 Sampling inspection frequency The ratio of the number of unit products randomly selected and inspected during the sampling inspection at the inspection station to the number of unit products passing through the inspection station is called the sampling inspection frequency. This standard recommends using fractions such as 1, 1/25, 1/50, etc. to express the sampling inspection frequency.
3.1.22 Continuous sampling inspection Continuous sampling inspection Through the inspection or testing of unit products passing through the inspection station, the unqualified products found by the screening inspectors or sampling inspectors in these unit products are eliminated, and the remaining uninspected unit products and qualified products continue to be transmitted down the production line. 3.1.23 Continuous sampling inspection plan Conlinuous sampling plan The specific procedure that stipulates 100% inspection of the continuous number of qualified products and sampling inspection with a specified sampling inspection frequency, as well as alternating between 100% inspection and sampling inspection, is called continuous sampling inspection plan. 3.1.24 Inspection by individual defect A continuous sampling inspection plan is used independently for the inspection of a single defect, or a continuous sampling inspection plan is used for the inspection of several defects separately, which is called single defect inspection. 3.1.25 Inspection by defect class A continuous sampling inspection plan is used for the inspection of several defects that are grouped together to form a type of defect, which is called type defect inspection.
3.1.26 Single-level continuous sampling inspection plan A continuous sampling plan that does not reduce the sampling inspection frequency according to the previous sampling inspection results is called a single-level continuous sampling inspection plan.
3.1.27 Multi-level continuous sampling inspection plan A continuous sampling inspection plan that can reduce the sampling inspection frequency according to the previous sampling inspection results is called a multi-level continuous sampling inspection plan.
3.1.28 Process average The percentage of nonconforming products in the initial inspection of the unit product submitted by the contractor is called the process average. The initial inspection does not include the inspection results of the unit product submitted again after rework. Synonyms: percentage of nonconforming products submitted unit product 3.1.29 Acceptable quality level The value that serves as an index to retrieve the continuous sampling inspection plan specified in this standard and has no other meaning is called the acceptable quality level.
3.1.30 Average outgoing quality average outgoing quality limit - 4 -
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SJ 20712—1998
For a specific process average, the percentage of unqualified units in the long unit sequence judged as qualified using the continuous sampling inspection plan is called the average outgoing quality (for the understanding of the meaning of the CSPF type continuous sampling inspection plan, see Section 5.2.1).
3.1.31 Average outgoing quality upper limit average outgoing quality limit The maximum value of all possible average outgoing qualities of the long-term continuous sampling inspection plan is called the average outgoing quality upper limit (for the understanding of the meaning of the CSP-F type continuous sampling inspection plan, see Section 5.2.1). 3.1.32 Nominal average outgoing quality upper limit target average outgoing quality limit The upper limit value of the average outgoing quality used to determine the parameters of the continuous sampling inspection plan is called the nominal average outgoing quality upper limit. Because there is no set of parameters for a continuous sampling inspection plan that is exactly equal to the nominal average inspection quality upper limit in all cases, the actual average inspection quality upper limit may be slightly different from the nominal average inspection quality upper limit.
3.1.33 Average inspection proportion averagefractioninspected For a specific process average, the percentage of unit products submitted to the inspection point using the continuous sampling inspection plan on a long unit product sequence is called the average inspection proportion. 3.1.34 Production time interval productioninterval The time interval before the normal shift change in the production process is called the production time interval. If it can be reasonably ensured that the shift change will not affect the quality of the product, the production time interval can be one day, but it should not exceed one day. 3.1.35 Sampling inspection characteristics operationalcharacteristics For a specific process average, the percentage of unit products judged as qualified during the sampling inspection period to the submitted unit products using a continuous sampling inspection plan on a long unit product sequence is called the sampling inspection characteristic. 3.1.36 Functional curve functionalcurve The curve that describes the relationship between certain characteristics of the continuous sampling inspection plan and the percentage of defective units submitted is called a functional curve. This standard provides methods for drawing functional lines (average pick-out quality curve, average inspection ratio curve and sampling inspection characteristic line) for the other four types of continuous sampling inspection plans except the CSPF type continuous sampling inspection plan.
3.2 Abbreviations
a. CSP-11 continuous sampling inspection plan
b. CSP-FF reverse sampling inspection plan
c. CSP-22 continuous sampling inspection plan
d. CSP-TT continuous sampling inspection plan
e. CSPVV continuous sampling inspection plan
f. A0Q average detection quality
g. AOQL average detection quality upper limit
SJ 20712—1998
Note: AOQL (%) means the value of AOQL is a percentage. h. AOL qualified quality level
Note: AQL (%) means the value of AQL is a percentage. i. AFI average inspection ratio
Note: AFI (%) means the value of AFI is a percentage. j. SFCL sampling inspection frequency code
k. OC sampling inspection characteristics
1. PA process average
m. PAest process average estimate
Note: PAest (%) means that the value of PAest is a percentage. 3.3 Symbols
P. (%) Percentage of unit products judged as qualified during sampling inspectiona.
bP (%) Percentage of unit products submitted as non-conformingc. Pull sampling inspection frequency
d. Number of consecutive qualified products
ex Number of consecutive qualified products
fS 100% inspection cumulative number of unit products inspectedg, N The number of unit products should be specified when using CSP-F type continuous sampling inspection plan 4 General requirements
4.1 Classification of defects and non-conformities
4.1.1 Classification of embedded
Classify the defects that may occur in unit products according to the severity of the defects. Generally, all defects are classified into one or several categories according to fatal defects, minor defects and minor defects. All defects can also be classified into other categories or subcategories of these categories.
4.1.2 Classification of nonconforming products
All nonconforming products are generally classified into fatal nonconforming products, major nonconforming products and minor nonconforming products. They can also be classified into other categories of nonconforming products.
4.2 Acceptable quality level
4.2.1 The acceptable quality level can be used together with the sampling inspection frequency code to retrieve the continuous sampling inspection plan specified in this standard. The continuous sampling inspection plan specified in this standard can also be retrieved according to the nominal average detection quality upper limit and the sampling inspection frequency code.
4.2.2 Limitation
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The provisions of the acceptable quality level should not be understood as the contractor having the right to deliberately supply nonconforming products. 4.2.3 Specification of acceptable quality levels
Quality levels are specified in military specifications, in the purchase contract or by the responsible party. Different acceptable quality levels may be specified for customer defects or for individual defects. 4.2.4 Preferred acceptable quality levels
The acceptable quality levels given in the tables of this standard are preferred acceptable quality levels. If acceptable quality levels other than the preferred acceptable quality levels are specified, these tables do not apply. 4.3 Maximum average detected quality
4.3.1 Limits
The upper limits of the nominal average detected quality given in the tables of this standard shall not be construed as giving the contractor the right to intentionally supply nonconforming product.
4.4 Submission of Unit Products
Although batches are not used for the selection of a continuous sampling inspection plan, it is practical to maintain this form based on the principles of quality uniformity, acceptance and ease of delivery. 4.4.2 Unit Product Sequence
In order to facilitate the discovery of the source of quality problems and take corrective measures, all single product sequences that have not yet been added should be inspected. For example, unit products from two or more identical production lines are combined before inspection: in this case it is not possible to maintain the unit product sequence. If the combination of unit products from these identical production lines is complete, the continuous sampling inspection plan specified in this standard can still be used. Therefore, it is essential to ensure that any non-conforming product in the unit product sequence has a time limit.
4.4.3 Unit Product Submission
It must be arranged so that all unit products can pass through each inspection position. There is no restriction on the contractor arranging process inspections before the unit products arrive at the inspection station, and there is no restriction on the contractor rejecting or returning defective unit products before the unit products are submitted. However, if the ordering party believes that the unit product sequence formed by the sequence inspection method arranged by the contractor during the screening and picking is not representative, and it is expected that such unit product sequence may appear in the future, the ordering party has reason to reserve the right to require the contractor to improve the sequence inspection method. 4.5 Acceptance and Rejection
4.5.1 ResponsibilitiesWww.bzxZ.net
Although both the contractor and the ordering party can reject (reject) unqualified products, only the ordering party has the right to accept (purchase) unit products. Since the contractor is responsible for the compliance of the submitted products with the contract requirements, the contractor will use a continuous sampling inspection plan indexed by the specified quality level to check whether the quality of the products submitted by the ordering party meets the contract requirements: 7
4.5.2 Special restrictions on fatal defects
SJ207t2-199B
The department responsible for fatal defects may arbitrarily require the inspection of each unit product, or perform another inspection procedure related to fatal defects. If a fatal defect has been found in a unit product, even if the current inspection does not find a unit product with a fatal defect, the contractor shall still perform the inspection procedure specified by the ordering party for the inspection of fatal defects.
4.5.3 Handling of non-conforming products
Non-conforming products in the unit product sequence shall be eliminated by the contractor or the ordering party, and the eliminated non-conforming products shall remain separated from the unit product sequence. The contractor may rework these non-conforming products and submit them to the ordering party again after 100% inspection in a state separated from the normal unit product sequence. If the ordering party considers these re-submitted unit products to be qualified, these unit products shall be immediately returned to the production line after the inspection station where these non-conforming products appeared.
4.6 Taking out samples
4.6.1 Samples
In the case of continuous sampling inspection, a sample is composed of a unit product randomly taken from a production line passing through a set inspection station, that is, a sample consists of a sample unit. 4.6.2 Sampling inspection frequency
The value of the sampling inspection frequency determines each sampling inspection plan. 4.6.3 Taking out sample units
The sample units taken out according to the selected sampling inspection frequency should give each unit product an equal chance. The sampling inspection personnel should allow the interval of the sample units to vary slightly. Instead of taking out the sample units strictly at the specified intervals.
4.7 Continuous Sampling Inspection Plan
4.7.1 Sampling Inspection Frequency Code
The sampling inspection plan is determined based on the sampling inspection frequency code. Table 1 provides the total number of unit products within the production time interval to determine the allowable sampling inspection frequency code. The sampling inspection frequency code and the corresponding sampling inspection frequency should be selected after considering the time for each unit product inspection, the processing cost and the influencing factors of other adjacent inspection stations. Among them, time is a major factor. It is usually better to choose a continuous sampling inspection plan with a larger batch inspection frequency and a smaller number of continuous qualified products. 4.7.2 Obtaining the continuous sampling inspection plan
Using the qualified quality level (or the upper limit of the nominal average detection quality) and the sampling inspection frequency code, the continuous sampling inspection plans of CSP-1, CSP-2, CSP-T and CSP-V can be obtained from Tables 2, 16, 18 and 20 respectively. Using the qualified quality level (or the upper limit of the nominal average detection quality), the sampling inspection frequency code and the specified unit price and product number, the continuous sampling inspection plan of CSP-F can be obtained from Tables 4 to 15. 8-
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