BS 6000-2:2005 pdf download
BS 6000-2:2005 pdf download.Guide to the selection and usage of acceptance sampling systems for inspection of discrete items inlots ——Part 2: Guide to sampling by attributes.
Procedure A is used when both the supplier and the customer wish to regard the lot in isolation, but it is also used as the default procedure where there is no specific instruction to use procedure B.
Procedure B is used when the supplier regards the lot as one of a continuing series, but the customer considers the lot received in isolation. The sampling plans employed permit a producer to maintain consistent procedures for customers. irrespective of whether the customers receive individual lots or a continuing series of lots. The manufacturer is concerned with all of the production but the individual customer only with the particular lot received.
For procedure A. sampling plans are identified by their lot size and t.Q; for procedure H. they are identified by lot size, LQ and inspection level,
Procedure A includes sampling plans with an acceptance number of zero. but these are excluded from procedure B. Double and multiple sampling plans can be used as alternatives to single sampling plans in procedure B and for the nun-zero acccpusrwe number plans in procedure A.
35 BS 6001-3: Skip-lot sampling procedures
This specifies a sampling system that extends the procedures specified in 55 6001.1. It provides generic attribute skip-lot sampling prucedures for reducing the inspection effort on products submitted by suppliers who have demonstrated their ability to control, in an effective manner, all facets of product quality and to produce superior quality material consistently. However, thcc procedures are proscribed for the inspection of product characteristics that involve the safety of personnel.
The skip-lot programme uses the acceptance sampling plans specified in BS 6001-1 and is intended only for a continuing series of lots; it is not appropriate for isolated lots. All lots in a series are expected to be of a similar quality and there should be no reason to believe that lots that have not been inspected are of a poorer quality than those that have.
In a skip-lot sampling procedure, some lots in a series are accepted without inspection when the sampling results for a stated number of immediately preceding lots meet stated criteria. The lots to be inspected arc chosen randomly with a stated frequency, called the “skip.lot frequency”.
3.6 BS 6001-4: Sequential sampling plans for percent nonconforming
This presents a sampling system that provides a wide range of sequent ial sampling plans indexed in terms of the consumer’s risk point (CRP) and the producer’s risk point (PRP). It also contains a sequential sampling system indexed by lot size ranges, inspection levels and AQL to supplement the system specified in BS 6001-i. including switching rules. (For the relationship between AQE, LQ. CRP and PRP. see Figure 1 and Figure 2.)
In sequential sampling, items are selected randomly and inspected one after another, and a cumulative count is kept of the number of nonconforming items or number of nonconformities. The decision that “sentences” the lot as acceptable or as not acceptable can occur at almost any stage and, for sequential sampling by attributes, depends on the number of items inspected and the cumulative number of nonconforming items or nmiconformities found p to that point.
1186001.4 provides procedures based on a sequential assessment of inspection results that maybe used to induce the supplier to supply lots of a quality with a high probability of acceptance while maintaining an upper limit for the risk to the consumer of accepting lots of poor quality. This is achieved by the economic and psychological pressure of non.aoceptancc of lots of inferior quality.
These sampling procedures are intended primarily for use in inspection of a continuing series of lots from the same production run. Subject to certain provisions, they may also be used for the inspection of lots in isolation.
In terms of the average number of items inspected per lot, BS 6001-4 offers sampling plans that are more economical than those specified in ItS 6001-1, albeit at the expense of an increase in administrative complication.
3.7 BS 6001-5: Procedures for assessment of declared quality levels
This provides sampling plans and procedures for assessing whether the quality level ola lot or process conforms to a declared value. The sampling plans have been devised to have a risk of less than 5 % of contradicting a correct declared quality level ([XL). Conversely, the risk is 10% of failing to contradict an incorrect DQL, which is related to the limiting quality ratio. Sampling plans are provided corresponding to three levels of discriminatory ability.
