Sampling procedures and tables for lot-by-lot inspection by attributes (Apply to inspection of successive lots or batches)
Some standard content:
National Standard of the People's Republic of China
Sampling procedures and tables for lot-by-lot inspection by attrlbutes (Apply to inspection of successive lots orbatches)UDC658.562:519
.2 : 620.11
GB 282 8
Replaces GB 282&
This standard specifies the first, second and fifth sampling plans and sampling procedures with the qualified quality level (expressed by the number of unqualified products per hundred units or the number of unqualified products per unit) as the quality indicator. It is applicable to the inspection of consecutive lots. 2 Terms and symbols
2.1 Terms
2.1.1 Unit product
The basic unit divided for the purpose of implementing sampling inspection is called unit product. For example: a single product, a pair of products, a group of products, a component or... a product of a fixed length, a fixed area, a fixed volume, a fixed quantity. It may or may not be consistent with the unit product specified for procurement, sales, production and shipment. 2.7.2 Inspection lot (abbreviated as: lot)
The unit products collected for sampling inspection are called inspection lot, abbreviated as lot. 2.1.3 Continuous lot
The batch to be inspected can be continuously submitted for inspection using the quality information provided by the most recent inspection batch, which is called a continuous batch. 2.1.4 Batch
The number of unit products contained in the batch is called the batch. 2.1. 5 Sample unit
The unit product extracted from the batch for inspection is called the sample unit. 2.1.6 Sample
The entirety of the sample units is called the sample.
2.1.7 Sample size
The number of sample units contained in the sample is called the sample size. 2.1.8 Nonconformity
A unit product’s quality characteristics that do not meet the requirements are called nonconformity. Nonconformity is classified according to the importance of the quality characteristics of the unit product, or according to the severity of the nonconformity of the quality characteristics. Generally, nonconformity is divided into: Class A nonconformity, Class 13 nonconformity, and Class C nonconformity. 2.1.9 Class A nonconformity
The unit product's most important quality characteristics do not meet the requirements, or the unit product's quality characteristics do not meet the requirements seriously, which is called Class B nonconformity:
2.1.10 Class B nonconformity
Approved by the National Bureau of Standards on December 11, 1987
Implemented on May 1, 1988
CB 2828 87
The unit product's important quality characteristics do not meet the requirements: or the unit product's quality characteristics do not meet the requirements seriously, which is called Class B nonconformity2. 1. 11 Class C nonconformity
The unit product's general quality characteristics do not meet the requirements, or the unit product's quality characteristics do not meet the requirements slightly, which is called Class C nonconformity.
2. 1. 12 Nonconforming products
The unit product with one or more nonconforming products is called a nonconforming product. According to the type of nonconformity, it can be generally divided into: Class A nonconformity, Class B nonconformity, and Class C nonconformity.
2.1.13 Class A nonconformity
A unit product with one or more Class A nonconformity, and possibly Class B and/or Class C nonconformity, is called Class A nonconformity.
2.1.14 Class B nonconformity
A unit product with one or more Class B nonconformity, and possibly Class C nonconformity, but not including Class A nonconformity, is called Class C nonconformity.
2.1.15 Class B nonconformity
A unit product with one or more Class C nonconformity, but not including Class A and Class B nonconformity, is called Class C nonconformity. 2.1.16 Number of nonconformity per 100 units of products The total number of all nonconformity in the batch divided by the batch size, and then multiplied by 100, is called the number of nonconformity per 100 units of products. That is: number of unqualified products per 100 units of products = total number of unqualified products in a batch × 109 batch
2.1.17 number of unqualified products per 100 units
The total number of unqualified products in all units of products in a batch divided by the batch, and then multiplied by 100, is called the number of unqualified products per 100 units of products. That is: number of unqualified products per 100 units of products = total number of unqualified products in all units of products in a batch × 100 batch
2.1.78 batch quality
The quality of a single batch submitted for inspection (expressed in the number of unqualified products per 100 units of products or the number of unqualified products per 100 units of products) is called batch quality. 2.1.79 process average
The average quality of a series of batches submitted for inspection for the first time (expressed in the number of unqualified products per 100 units of products or the number of unqualified products per 100 units of products) is called process average.
Note: The first batch submitted for inspection includes the batches that are judged as unqualified in the first submission for inspection and are resubmitted for inspection after rework. 2.1.20 Acceptable quality level
In sampling inspection, the average upper limit of the process of continuously submitted inspection batches that are considered acceptable is called the acceptable quality level. 2.1-21 Inspection
The process of comparing a single product with the technical requirements by measurement, test or other methods is called inspection. 2.1.22 Counting inspection
Determining whether a unit product is a qualified product or a non-qualified product, or calculating the number of non-qualified units of products according to a group or a technical requirement specified in the product technical standard is called counting inspection. 2.1.23 Batch inspection
In order to determine whether the batch quality of each batch submitted for inspection meets the specified requirements, the inspection of 100% or sampling from the batch is called batch inspection.
2.1.24 Qualified judgment number
The maximum number of non-qualified products or non-qualified numbers allowed in the sample for making a batch qualified judgment is called the qualified judgment number. 2.1.25 Unqualified judgment number
GB2828—87
The minimum number of unqualified products or unqualified numbers not allowed in the sample for making a batch unqualified judgment is called the unqualified judgment number. 2.1.26 Decision array
The qualified judgment number and the unqualified judgment number or the qualified judgment number series and the unqualified judgment number series are combined together, which is called the decision array. 2.1.27 Sampling plan
The sample size or the sample size series and the decision array are combined together, which is called the sampling plan. 2.1.28 Sampling procedure
The process of using the sampling plan to judge whether the batch is qualified or not is called the sampling procedure. 2.1.29 The primary sampling plan
consists of the sample size, and the decision array [A, R. The sampling plan composed of the first sample size, the second sample size and the judgment array [A, , , , , ] is called a one-time sampling plan: 2.1.30 Two-time sampling plan
The sampling plan composed of the first sample size, the second sample size and the judgment array [A, , , , , , , ] is called a two-time sampling plan.
2.1.31 Five-time sampling plan
The sampling plan composed of the first sample size, the second sample size, the third sample size, the fourth sample size, the fifth sample size, and the judgment array [A, ... 34 Relaxed inspection
The inspection conducted when the process average is significantly better than the qualified quality level is called relaxed inspection. 2.1.35 Extra wide inspection
The inspection conducted when a batch that was judged as unqualified by an extra wide inspection is re-judged is called extended inspection. 2.1.36 Inspection level
The hierarchical correspondence between the batch size and the sample size of the batch submitted for inspection is called the inspection level. 2.1.37 Sample size code
The letter code for the sample size determined according to the batch size and the inspection level of the batch submitted for inspection is called the sample size code. 2.1.38 Batch conformity probability
For a batch with known quality, the probability of judging the batch as a qualified batch according to a given sampling plan is called the batch conformity probability. 2.1.39 Half-mean sample size
For a batch with known quality, the probability of judging the batch as a qualified batch according to the given sampling plan is called the batch conformity probability. Batch + According to the given sampling plan to make a qualified or unqualified judgment, the average number of sample units required to check the batch is called the average sample size.
2..40 Random inspection characteristic curve (°C curve)
The relationship curve between the probability of batch qualification and batch quality determined by a given sampling plan is called the sampling characteristic curve. 2.1.41 Average sample size curve (A8N curve) The relationship curve between the average sample size and batch quality determined by a given sampling plan is called the average sample size curve. 2.2 Special number
N:Batch.
+sample size
Note. When it is necessary to distinguish the first sample size and the second sample size, add the full code 1, 2, \ respectively. For example: represents the fifth sample size. 4, : qualified judgment number.
R. Unqualified judgment number.
GB 2828-- 87
Note. When it is necessary to distinguish the first, second, qualified and unqualified judgment numbers, change the full code and to 1, 2 respectively. For example, A in the second qualified judgment number, R. represents the second unqualified number: [A, RJ: the judgment array of the first sampling plan. [Ai, A, average, RI; the judgment array of the second sampling plan. [A..A, A, A., A.: R.·H., R,, R,]. The judgment array of the fifth sampling plan. Hope: batch quality.
? ! Process average.
AQL: Acceptable quality level.
P probability of batch acceptance.
AN: Average sample size.
1L: Inspection level.
k; Limit number
3 Inspection procedure
The inspection procedure specified in this standard is as follows:
. Specify the quality characteristics of unit products:
h Specify the classification of unqualified products;
Specify the quality level of the product
d. Specify the inspection level;
e Composition and proposal of inspection batches:
f. Specify the strictness of inspection;
, select the type of sampling plan;
h. Search the sampling plan;
Select the sample;
i-Inspection sample;
k: Determine whether the batch inspection is qualified or qualified
1 Treatment after batch inspection,
4 Implementation of inspection
4.1 Specify the quality characteristics of unit products
In the product technical standards or order form, the quality characteristics of the unit products such as technical performance, technical indicators, and appearance must be clearly specified. 4. 2 Classification of unqualified products
According to actual needs, unqualified products can be divided into Class A, Class B, and Class C categories. Note: If necessary, the non-conformity of multiple types of agents can be distinguished. In other cases, when the unit product is relatively simple, it can also be distinguished into two categories of non-conformity, or even no distinction is made.
4. 3 Provision of qualified quality level
In the product technical standards or order contracts, the qualified quality level should be determined by negotiation between the ordering party and the supplier. The qualified quality level for non-conformity can be stipulated in different ways. In principle, different qualified quality requirements are stipulated according to the classification of non-conformity. The qualified quality level stipulated for Class A should be lower than the qualified quality level stipulated for Class B, and the qualified quality level stipulated for Class C should be higher than the qualified quality level stipulated for Class 1. In addition, it is possible to consider stipulating the qualified quality level for some or individual non-conformities in the same category, or to consider stipulating the qualified quality level between different categories. In Tables 3 to 11. The qualified quality level values less than or equal to 10 can be the number of defective products per 100 units of product or the number of defective products per unit of product. The qualified quality level values greater than 10 can only be the number of defective products per 100 units of product. In addition, the quality level values given in these tables are priority values. If the specified qualified quality level is not a priority value, these tables are not applicable. 4.4 Provisions for inspection levels
GB 282887
This standard gives three general inspection levels I, 1, I1 and four special inspection levels: S-1, S-2, S-3 and S-4 in Table 2. Unless otherwise specified, the general inspection level II is usually used. When the required discrimination power is relatively low, the general inspection level 1 can be specified, and when the required discrimination power is relatively high, the general inspection level l can be specified. Special inspection levels are only applicable when smaller samples must be used, and H can or must allow for a greater risk of misjudgment.
In principle, the inspection level is specified according to the classification of unqualified products, but attention must be paid to the coordination between the inspection level and the qualified quality level. Note: When specifying special inspection levels S-1 to S-4, care must be taken to avoid conflicts between the inspection level and the specified quality level. For example, in St, the sample size code does not exceed D. When the sample size of a normal inspection single sampling case is at most 8, if AQI.0-0.10 is specified, the minimum sample size of a normal inspection single sampling case is 125. Therefore, when A(L=1.10 is specified, the use of special inspection level s-1 cannot be specified. 4.5 Formation and submission of inspection batches. Unit products can be simply collected to form inspection batches, or they can be formed in other ways. Inspection batches can be the same as or different from production batches, sales batches, and transportation batches. Usually, each inspection batch should be composed of unit products of the same model, grade, type (size, characteristics, ingredients, etc.), and with basically the same production conditions and production time. The composition of the batch, the way to submit and identify the batch, should be determined by negotiation between the supplier and the ordering party. If necessary, the supplier should provide appropriate storage places for each batch submitted for inspection, the equipment required for identification and submission, and the personnel required for management and sampling. 4. 6 Determination of inspection strictness
The strictness of inspection refers to the degree of strictness of the inspection received by the submitted batch. This standard stipulates three different inspection strictness: normal inspection, strict inspection and relaxed inspection, and determines the inspection strictness of the submitted inspection batch according to the speed principle. 4.6.1 Start of inspection
Unless otherwise specified, normal inspection should be used at the beginning of the inspection. 4.6.2 Continuation of inspection
Except for the need to change the inspection strictness according to the transfer rule in 4.6.3: the inspection strictness of the next batch will continue to remain unchanged. In principle, the change of inspection strictness is carried out according to different types of non-conformities, and it is allowed to give unified regulations for changing the inspection strictness between different types of non-conformities.
4.6. 3 Transfer rules
. From normal inspection to tightened inspection
When conducting normal inspection, if two batches out of no more than five consecutive batches fail the initial inspection (excluding the batches submitted for inspection again), the next batch inspection shall be transferred to the tightened inspection.
b. From tightened inspection to normal inspection
When conducting tightened inspection, if five consecutive batches pass the initial inspection (excluding the batches submitted for inspection again), the next batch inspection shall be transferred to the normal inspection.
. From normal inspection to relaxed inspection
When conducting normal inspection, if the following conditions are met, the next batch shall be transferred to the relaxed inspection. (1) 10 consecutive batches or The first inspection of the new batch (excluding the resubmitted batch) as specified in the Note to Table 1 is qualified; (2) In the samples taken from 10 consecutive batches or more batches as specified in the Note to Table 1, the total number of non-conforming products (or non-conforming products) is less than the limit number specified in Table 1;
(3) Normal production;
(1) The competent quality department agrees to transfer to relaxed inspection. d. From relaxed inspection to normal inspection
During the inspection, if any of the following situations occur, the next batch will be transferred to normal inspection: 1) One batch fails the relaxed inspection;
(2) Abnormal production:
(3) The competent quality department considers it necessary to return to normal inspection. 2828-87
After the tightened inspection has been started, if the number of unqualified batches (excluding the batches submitted for inspection again) accumulates to five batches (excluding the number of unqualified batches that were previously transferred to the tightened inspection and found in the suspension and resumption of inspection in 4.6.4), the inspection according to this standard shall be temporarily suspended. After the inspection is suspended, if the supplier has indeed taken measures to make the inspection batch meet or exceed the specified quality requirements, the inspection may be resumed with the consent of the competent quality department, and generally it should start from the tightened inspection. Table 1 Limit number (L)
Cumulative sample size
0. 010* 0.015
10~159
160~199
200~249
250--314
315--399
400~ 489
500~~629
630-799
800--999
1 000~1 249
1250--1 599||tt ||1600~1999
2000~2499
2 500~-3 149
31503999
4000--4999
5000-6299
6 300~7 999
80009999
10000-12499|| tt||1250015999
16 000--19 999
20000--24999wwW.bzxz.Net
25000--31499
31500309
10000-49999||tt ||50000-~62999
0.0400.065
263 000
Note: "For this qualified quality buffalo, the cumulative sample size of 10 consecutive qualified batches is not enough for the research inspection. The sample size of consecutive qualified batches must be calculated. The limit numbers can be compared. If a batch of unqualified results appears during the acceptance test, the results of the previous inspection of this batch cannot be used in the future.
Cumulative sample size
13---15||tt ||16--10
25~-31
40 --19
63--79
[00-~[24
125-159
160-199
200~249||tt ||250314
316--399
100-499
500~629
630-799
800--999
1000-1249
1 250~-1 599
1 600-1999
2 000-~2 499
2500~3 149
3 150--3 999
1000-999
4.7 Selection of sampling plan type
GB 2828 87
Continued Table 1
This standard is in Tables 3 to 6, 7 to 10, Tables 11 to 14 give three types of sampling schemes: one time, two times and five times. For a given set of quality water and inspection water, different types of corresponding sampling schemes can be used. Based on the management costs and average sample sizes of various types of corresponding sampling plans, it is quickly decided to use one of the three, two and five sampling plans. The average sample size of the sampling scheme is smaller than the average sample size of the corresponding sampling scheme (except for the one corresponding to the decision array [!, 21). The average sample size of the sampling scheme is smaller than the average sample size of the corresponding one sampling scheme. (See Figures 12 to 30). In addition, the management cost is often a five-time sampling plan with a high-Ding corresponding to a "three-time sampling plan", and a three-time sampling plan with a high-Ding corresponding to a -three-time sampling plan. However, as long as the specified qualified quality level and the inspection level are consistent, regardless of the use The sampling plan for the type of plastics in this standard is basically the same for the judgment of batch quality. The type of sample should be guaranteed for relaxation and special inspection. 4.8 Selection of sampling plan
GB2828-87
According to the sample size code and the quality level, search for the sampling plan in Tables 3 to 11. 4.8.1 Sample size code
Use Table 2 to select the batch size of the batch submitted for inspection. Read the sample size code at the intersection of the row and the column where the specified inspection level is located. 4. 8. 2 Inspection of one-time sampling plan
Search for normal inspection-sampling plan using Table 3 Search for strict inspection-sampling plan using Table 4, search for relaxed inspection-sampling plan using Table 5. Search for extra wide inspection-sampling The scheme uses Table 6. Search method: From the sample too small code obtained in 4.8.1, read the sample size in the sample size column horizontally to the right, and then find the intersection of the sample size code row and the specified qualified quality column. , read out the judgment array "A". If there is an arrow at the intersection, follow the direction of the arrow and read out the first Then, turn left from the row where the decision array [A, R, is located, and read the corresponding sample size n in the sample size column. Note: ① According to the above case detection method, for the unclassified When different sample sizes are obtained for non-conforming products or different types of non-conforming products, the corresponding sample size can be used.
② If the ordering party agrees, Use the sampling plan of the decision array [1,27] instead of the sampling plan of the decision array [0,1]. Example 1 In the factory test of a mechanical part, GB 2828. Given AQL = 1.5, IL = II, find the sampling plan for the regular inspection when N = 2000.
Month: From Table 2, the row (12013200) containing N = 2000, and T = [1] At the intersection of the columns, read the sample too small code K. b. Because we need a normal inspection and sub-sampling plan, we use Table 3 for retrieval. c. In Table 3, go right from the row where the sample size code K is located. , read = 125 in the sample size column. In addition, read [5,6] at the intersection of the sample size code K row and AQL-1.5 column. d. Therefore, the required positive belt inspection single sampling plan As follows: n — 125, Ae 5, Re = 6 ,
Example 2 In the acceptance test of a certain electronic component, GB2828 is used. The regulations AQL=0.10, 1L=I, and the strict inspection is required when N=1000.
-From Table 2 contains rows (501 to 1200) where N = 1000, and the intersection with the column where IL. = 1, read the sample size code G. b. Because we need to strictly check the sampling plan, we use Table 4 to perform c. In Table 4, go right from the row with the sample size half code and enter 32 in the sample size column. However, the intersection of the row where the sample size code is located and the column where AQL=0.40 is located shows a downward arrow, so the first decision array [0, 1] is read along the direction indicated by the arrow, and then [0, 1 Go left in the row where you are and read 50"d in the sample size column. Therefore, the required sampling plan is as follows: n= 50, 4, - 0, = 1.
e, if you need to If the judgment array is [0, the gate scheme is changed to the scheme where the judgment array is [1,2], then the following strict inspection sampling scheme can be used.
#- 200.A=1,R=2| |tt||Substituting the above scheme,
Example 3 In the acceptance test of electronic components, 1 2828 is adopted. The AQL of Class A nonconforming is specified to be 0. 65, B AQL=2.5IL=Il. Find the normal inspection sampling plan when N-400. That is, follow the steps in Example 1 to find the normal inspection sampling plan for Class A unqualified products: n= 80, A = 1 , R = 2
The normal inspection sampling plan for 11 types of unqualified products is: n = 50, A = 3. R.= 1
b, in order to make the sample size of the normal inspection and sampling plan of Class A and Class B unqualified products consistent, the normal inspection and sampling plan of Class B unqualified products can be changed to:||tt| |4.8.3 Inspection plan of subsampling method
GB2828-87
#-80,A-5-6
Retrieve normal band inspection subsampling plan using Table 7 . The search for strict inspection and subsampling scheme uses Table 8. The search for wide inspection and subsampling scheme uses Table 9. The search for extra wide inspection and subsampling scheme uses Table 10. Search force method: use 1.8.2 Method: Read out the sample size,, the sample size and the decision array LA, A, R., R. Example 1: Under the same conditions as in Example 1, find the normal inspection subsampling plan. 1. Sample size code is K (same as Example 1). b. In order to find a normal inspection subsampling plan, the country uses Table 7 for retrieval. c. In Table 7, go right from the row where the sample size code K is located, and in the small column of sample number The reading is 1: 80. In addition, the intersection of the row where the sample is located and the column where AQL=1.5 is located reads 2, 6, 5, 7. d. The required normal inspection sampling plan is as follows: Attached 80, A, - 2,= 5
n: =80, A26, R=7
4.8.4 Retrieval of five-time sampling scheme
Retrieve the normal inspection sampling scheme using Table 1. Retrieve the five-time sampling scheme for strict inspection using Table 12. Retrieve the five-time sampling scheme for relaxed inspection using Table 13. Retrieve the five-time sampling scheme for extra-wide inspection using Table 14. Retrieval method: Use the method in 1.8.2 to read the first sample size ≤, the second sample size ≤, the second sample size ≤, the fourth sample size ≤, the fifth sample size ≤, and the judgment array A, A, A, A, A:, R: R, R,,,,, B, Example 5 Under the same conditions as Example 1, find the normal inspection five-time sampling scheme. . The sample size code is (same as Example 1). b. Because the normal inspection five-time sampling scheme is required, Table 11 is selected for the search. c. In Table 11, from the row where the sample size code K is located to the right, read 一一㎡—=32 in the sample size column. In addition, from the intersection of the row where the sample size code 5 is located and the column where AQ1.=1.5 is located, read [#, 1, 2.4, 6, 4, 5, 67, 7! d. Therefore, the required five-time sampling plan for normal inspection is as follows: 8 - 32, A, = # + R = 4
H=32, A=1, R.5
, -32. A,-2, R,=6
=32, A-4. R=7
ms - 32, 4, - 6. R, =-7
Note: # means that the judgment of batch acceptance cannot be made at this time. 4. 9 Sample extraction
The sample should be extracted in a way that can represent the batch quality list. When the inspection batch consists of several layers, the samples shall be drawn by stratified sampling method. When using the two-time and five-time sampling schemes, each sample unit shall be drawn from the entire batch. The time of drawing samples can be during the batch formation process or after the batch is formed. 4.10 Inspection of samples
According to the inspection items specified for unit products in the product technical specifications or order contracts, the sample units shall be inspected one by one, and the total number of non-conforming products or the total number of non-conforming products shall be accumulated (when the non-conforming products are classified, they shall be counted separately). 4.11 Judgment of qualified or unqualified batch inspection GE 282B-87
4.11.1 Judgment method of qualified or unqualified batch inspection According to the sampling scheme determined by the qualified quality level and inspection level, the judgment shall be made using the methods provided in 4.11.2, 4.11.3 and 4.11.4. Only if it is judged to be qualified according to all the sampling schemes, can the inspection batch be judged to be qualified. Otherwise, the inspection batch shall be judged to be unqualified.
4.11.2 The case where the number of defective products per hundred units of product is used to express the batch quality 8: Soft sampling plan
According to the results of sample inspection, if the number of defective products found in the sample is less than or equal to the qualified judgment number, the batch is judged to be a qualified batch. If the number of defective products found in the sample is greater than or equal to the unqualified judgment number, the batch is judged to be an unqualified batch. b. Secondary sampling plan
According to the results of sample inspection, if the number of unqualified products found in the first sample is less than or equal to the first qualified judgment number, the batch is judged to be a qualified batch. If the number of defective products found in the first sample is greater than or equal to the first unqualified judgment number, the batch is judged to be an unqualified batch. If the number of defective products found in the first sample is greater than the first qualified judgment number and less than the first unqualified judgment number, the second sample is drawn for inspection. If the sum of the number of defective products found in the first, second and second samples is less than or equal to the first qualified judgment number, the batch is judged to be a qualified batch. If the sum of the number of unqualified products found in the first and second samples is greater than or equal to the second unqualified determination number, the batch is judged to be an unqualified batch.
c. Five-time sampling plan
According to the results of the sample inspection, if the number of unqualified products found in the first sample is less than or equal to the first qualified determination number, the batch is classified as a qualified batch; if the number of unqualified products found in the second sample is greater than or equal to the first unqualified determination number, the batch is judged to be an unqualified batch. If the number of unqualified products found in the first sample is greater than the first qualified determination number and less than the second unqualified determination number, the second sample is drawn for inspection: if the sum of the number of unqualified products found in the second and second samples is less than or equal to the first qualified determination number, the batch is classified as a qualified batch. If the sum of the number of unqualified products found in the first and second samples is greater than or equal to the second qualified determination number, the batch is judged to be an unqualified batch.
If the sum of the number of unqualified products found in the first and second samples is greater than the second qualified determination number and less than the second unqualified determination number, the third sample is selected for inspection. If the sum of the number of unqualified products found in the first to third samples is less than or equal to the third qualified determination number, the batch is judged to be a qualified batch. If the sum of the number of unqualified products found in the first to second samples is greater than or equal to the first unqualified determination number, the batch is judged to be an unqualified batch.
If the sum of the number of unqualified products found in the first to second samples is greater than the third qualified determination number and less than the first unqualified determination number, the third sample is selected for inspection. If the sum of the number of unqualified products found in the first to fourth samples is less than or equal to the fourth qualified determination number, the batch is judged to be a qualified batch. If the sum of the number of unqualified products found in the first to fourth samples is greater than or equal to the fourth unqualified determination number, the batch is judged to be an unqualified batch.
If the sum of the number of non-conforming products found in the first to fourth samples is greater than the fourth qualified judgment number and less than the fourth unqualified judgment number, the fifth sample shall be selected for inspection. If the sum of the number of non-conforming products found in the first to fifth samples is less than or equal to the fifth qualified judgment number, the batch shall be judged as a qualified batch. If the sum of the number of non-conforming products found in the first to fifth samples is greater than or equal to the fifth unqualified judgment number, the batch shall be judged as a qualified batch.
4.11.3 When the number of non-conforming products per hundred units is used to express the batch quality, the judgment procedure of 4.11.2 shall apply except that the word "non-conforming product" is replaced by "non-conforming". 4.11.4 Special circumstances
. Special provisions for relaxed inspection
Batches judged as unqualified by relaxed inspection must be re-judged by extra-wide inspection. If a one-time sampling scheme is used, the inspection results only need to be judged according to the corresponding wide inspection: If a two-time or five-time sampling scheme is used, in addition to judging according to the corresponding wide inspection, it is possible to continue sampling + until a judgment is made, b, the sample size is equal to or greater than the batch size. When the sample size of the sampling scheme is equal to or greater than the batch size, the batch size is regarded as the sample size, and the judgment matrix of the sampling scheme remains unchanged.
4.12 Disposition after batch inspection
GB282887
If it is judged to be qualified, the whole batch will be accepted, and the ordering party is allowed to propose certain additional conditions to the supplier on the basis of negotiation. In principle, all batches judged to be unqualified will be returned to the supplier or the supplier and the ordering party will negotiate to resolve. For products that have passed batch-by-batch inspection and are temporarily put into storage but have not been immediately delivered to the ordering party, if they are stored in the warehouse for more than a certain period of time (the specific time should be specified in the product technical standards or order contract), they must be re-inspected batch by batch and can only be delivered to the ordering party after passing the inspection. For batches that fail to pass the re-inspection, they will be treated as resubmitted inspection batches. Resubmission of non-conforming products
Regardless of whether the batch is accepted or rejected, and regardless of whether the non-conforming products are part of the sample, as long as they are non-conforming products found during the inspection, the ordering party has the right to refuse to accept them. The rejected non-conforming products can be repaired or corrected, and with the consent of the ordering party, they can be resubmitted for inspection in the prescribed manner.
b. Resubmission of non-conforming batches
On the basis of self-inspection of the non-conforming batches, the supplier shall submit the non-conforming batches found After the unqualified products are removed or repaired, they are allowed to be submitted for inspection again.
For the batches submitted for inspection again, whether to use normal inspection or strict inspection, whether to check all types of non-conformities or only check the individual types of non-conformities that cause the batch to be non-conformities, shall be determined by the ordering party. 5. Sampling element sampling characteristic curve and average sample size curve 5.7 Sampling plan sampling characteristic curve (>° curve) Figure 1 and Figure 11 of this standard are based on the normal inspection design single sampling plan judgment array A.,,1 as the order, based on the Poisson distribution, the sampling characteristic curves of the tightened, relaxed and extra wide inspection design single sampling plan corresponding to the normal inspection design value single sampling plan are given on the same figure. At the same time, the sampling characteristic curves of the design value double and five sampling plans are basically the same as the sampling characteristic curves of the corresponding design value single sampling plan.The above is maintained: -consistent.
The horizontal coordinates of the sampling characteristic curve given in this standard are all based on the ratio of batch quality P to AQL. If the horizontal axis coordinate value is multiplied by AQ, the sampling characteristic curve of a sampling plan with the horizontal axis coordinate as the sampling characteristic curve can be obtained. According to the above method, the sampling characteristic curves of the single sampling plans in Tables 3 to 6 of the standard (except for the single sampling plans determined by the sample number A and B in Tables 5 and 6) are almost consistent with the sampling characteristic curves of the single sampling plans in Tables 3 to 6 based on the Poisson distribution. At the same time, the sampling characteristic curves of the 4-time and 5-time sampling plans in Tables 7 to 14 based on the Poisson distribution are also basically consistent with the sampling characteristic curves of the corresponding single sampling plans based on the Poisson distribution. 5.2 Average Sample Size Curve of Sampling Plan (ASV Outline) Figures 12 to 30 of this standard use the design value single sampling plan judgment array [A, converted into sequence, and based on Poisson distribution, the average sample size curves of the design value double and five sampling plans corresponding to the design value single sampling plan are given on the same graph. The horizontal axis coordinates of the average sample size curve given in this standard are all based on the product of the sample size of the design value single sampling plan and the batch quality P. If the horizontal axis coordinate value is divided by the sample size of a certain sampling plan, the horizontal axis coordinate can be obtained, and the average sample size curve of the one-time and five-time sampling plans corresponding to the one-time sampling plan can be obtained. According to the above method, the average sample size curves of the one-time and five-time sampling plans in Tables 7 to 11 corresponding to the one-time sampling plans in Tables 3 to 6 of this standard are almost consistent with the average sample size curves of the two-time and five-time sampling plans based on Poisson distribution in Tables 7 to 14.
GB 2828 87
Sample size code
Batch profit model
16 --25
91~-150
151~280
281--500
501--1 20?
[201-~3 200
3 201--10 000
1000135000
35 001 ~150 000
150 011~500 000
:500 001
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