Question

Q] What are the advantages and disadvantages of acceptance sampling over 100% inspection? Under what conditions should acceptance sampling be preferred over 100% inspection?

Subject - Materials Management

Answer 1

Before going to the advantages and disadvantages of Acceptance Sampling, first, we need to understand what exactly is acceptance sampling.

Acceptance Sampling: Acceptance Sampling is a statistical quality control technique, where a random sample is taken from a lot and based on the results of the sample taken, the entire lot will either be accepted or rejected.

It can also be defined as the form of inspection that is used to determine whether or not products are coherent with a specified standard quality.

Advantages of Acceptance Sampling over 100% inspection:

i) It is economical, as inspecting all good/products can be very expensive.

ii) Fewer inspectors to put on payroll compared to 100% inspection (i.e. lesser workforce required for acceptance sampling

iii) Inspecting all goods can be very tedious and time taking compared acceptance sampling.

iv) Less handling damages-Testing all products can sometimes induce defects in the product(While handling), whereas in acceptance sampling only a few products are tested so the chances of inducing defect are negligible.

Disadvantages:

i) Though Acceptance sampling is economical and time taking, it provides comparatively lesser information than 100% inspection.

ii) There is always a risk associated with the process of a good lot being rejected and a bad lot being selected, based on the sample data.( These are also called Type-I error and Type-II error)

When is Acceptance Sampling preferred over 1000% inspection?

i) When the inspection/testing method is of the destructive type because 100% inspection will be more tedious, and all good will be broken before knowing whether it is good or bad.

ii)When the inspection method is expensive and time taking, Acceptance Sampling is preferred.

iii) From a manufacturer's perspective, if the past record of suppliers has been good. Acceptance Sampling can be preferred over 100% inspection to check the quality of the