Single Sampling Plan<\/h3>\n

First of all, let\u2019s consider the single-sampling plan. Basically it is an assessment rule depending upon the outcomes of one random sample from a lot to receive or reject the lot. Its process includes choosing a random sample size (n) and checking all items. The complete lot is accepted by the receiver when the defects numbers does not go beyond a definite acceptance number (c). If any defects are observed in the sample then they are either fixed or given back to the producer. Although, as compared to the other plans this form of sampling plan is not complicated and can be used easily, but generally we can see a higher ANI in the end.<\/p>\n

Double Sampling Plan<\/h3>\n

When double sampling plan is used for our receiving inspection sampling plan, there two sample sizes (n1 and n2) and two acceptance numbers (c1 and c2) selected by the management in a double-sampling plan. The lot can be accepted or rejected by the receiver and the final decision is made on the basis of the first sample. In order to implement this sampling plan, a random sample of size n1 is selected by the receiver. When the defects number is below or the same as (c1), the lot is accepted by the receiver. In case of defects number exceeding (c2), the lot is rejected by the receiver. The receiver chooses to select a second sample of size n2 when the defects number lies between c1 and c2. The lot is accepted by the receiver when the combined defects number in the two samples is below or equivalent to c2. The lot is rejected by the receiver otherwise. Certainly, by using double-sampling plan we can considerably decrease the inspection costs in relation to a single-sampling plan for lots with an extremely small or great amount defective since it can be chosen once the first sample is taken. On the other hand, the sampling costs can be exceeding compared to the single-sampling plan when it the final choice has to be made requiring two samples.<\/p>\n

Sequential Sampling Plan<\/h3>\n

Furthermore, an additional enhancement of the double-sampling plan is the sequential-sampling plan. In this sampling plan items are chosen by the receiver randomly from the lot and they are inspected in sequence. Based on the collective results to this point, a choice is made to reject or accept the lot or to carry on the sampling process when each time an item is checked. The expert plots the overall defectives number in contrast to the cumulative sample size, and the lot is accepted by the receiver when the defectives number is below a definite acceptance number (c1). The lot is rejected by the receiver in case the number is larger than a different acceptance number (c2). More to the point, an additional item is inspected when the number lies anywhere between the two. For the sequential-sampling plan the ANI is normally lower than any other method of acceptance sampling which means reduced inspection costs. On the whole, this form of sampling plan can decrease the ANI up to 50 percent of that essential by a similar single-sampling plan and, as a result provides the opportunity of saving considerable inspection expenditures wen it is selected as our receiving inspection sampling plan.<\/p>\n