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This type of sampling plan is normally used on batches or lots prior to shipping to a customer, to ensure that the outgoing quality matches the specified level for customer acceptance. Several samples are taken randomly, and the number of defectives counted. If the number of defectives exceed a certain number for that sample size the batch is rejected, and 100 percent inspection carried out. Defective items are then removed and replaced with good items ensuring....
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Double sampling plans generally require less sampling than single sampling plans but are more complicated to use....
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The BIS.Net Team
For a double sampling plans you take a first sample consisting of n items and each item is checked to see if it is defective. The number of defective items is then counted and compared with the first sample acceptance value for the sampling plan. If the number of defectives is less or equal to the first sample acceptance value the batch is rejected....
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The BIS.Net Team
This type of sampling plan, as is the AOQL plan, is normally used on batches, or lots prior, to shipping to a customer ensuring that the outgoing quality matches the specified level for customer acceptance. Several samples are taken randomly, and the number of defectives counted. If the number of defectives exceed a certain number for that sample size the batch is rejected, and 100 percent inspection carried out....
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The BIS.Net Team
This type of sampling plan can be used on batches, or lots prior to shipping to a customer when rectification is not possible. For example, when testing cans of soft drink for composition, rectification is not possible because every can would have to be opened to test the composition and decide which cans needs replacing. More often the plan is used to screen incoming goods. Rejected batches are returned to the supplier....
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The BIS.Net Team
A sampling plan consists of a sample size and acceptance value. A lot is rejected if the number of defectives in the sample size exceeds the acceptance value....
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The BIS.Net Team
This sampling plan must not be confused with Lot Tolerance Percent Defective sampling plans. Instead of taking a sample of n items and counting the number of defectives, a sample of n items is taken, and the number of defects counted. Rectification plans are not applicable for defects sampling plans....
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An OC curve is an important tool for the analyst to assess the protection a given sampling plan provides....
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The BIS.Net Team
An OC curve is an important tool for the analyst to assess the protection a given sampling plan provides. It is not uncommon practice to set arbitrary sampling plans e.g. take a sample size of 5 and reject the batch if there are more than zero defectives. The OC Curve permits the analyst to evaluate the effectiveness of such plans....
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Variables acceptance sampling plans are used when quality characteristics are measured on a continuous scale. Variables sampling plans tend to be more efficient than Attributes Sampling plans with a much lower sample size....
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The BIS.Net Team
This type of sampling plan protects against the receipt, or release of lots with excessive defectives. Defectives are items where measurements fall outside specification limits. For example moisture content may be specified for a delivery of a raw material. If the percentage of moisture that falls outside specification limits is excessive the lot will be rejected....
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The BIS.Net Team
There are two types of sampling plans provided for fraction defectives plans. One is for standard deviation known and the other standard deviation unknown. This plan is used if the standard deviation is unknown....
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