Methods of inspection
There are two methods of inspection.
100% inspection and sampling inspection.
1-100% inspection
This type will involve careful inspection in detail of quality at each strategic point or stage of manufacture where the test is involved is non-destructive and every piece is separately inspected.
It requires more number of inspectors and hence it is a costly method. There is no sampling error.
This is subjected to inspection error arising out of fatigue, negligence,difficulty of supervision etc.
Hence,completer accuracy of influence is seldom attained. It is suitable only when a small number of pieces are there or a very high degree of quality is required for Example:
Jet engines,aircraft,medical and scientific equipment.
2-sampling inspection
In this method randomly selected samples are inspected. Samples taken from different patches of products are representatives.
If the sample proves defective,the entire concerned is to be rejected or recovered.
Sampling inspection is cheaper and quicker.It requires less number of Inspectors.
It is subjected to sampling errors but the magnitude of sampling error can be estimated.
In the case of destructive test,random or sampling inspection is desirable.
This type of inspection governs wide currency due to the introduction of automatic machines or equipments which are less susceptible to chance variable and hence require less inspection,suitable for inspection of products which have less precision importance and are less costly.
Example: Electrical bulbs,radio bulbs,washing machine etc.
There are two methods of inspection.
100% inspection and sampling inspection.
1-100% inspection
This type will involve careful inspection in detail of quality at each strategic point or stage of manufacture where the test is involved is non-destructive and every piece is separately inspected.
It requires more number of inspectors and hence it is a costly method. There is no sampling error.
This is subjected to inspection error arising out of fatigue, negligence,difficulty of supervision etc.
Hence,completer accuracy of influence is seldom attained. It is suitable only when a small number of pieces are there or a very high degree of quality is required for Example:
Jet engines,aircraft,medical and scientific equipment.
2-sampling inspection
In this method randomly selected samples are inspected. Samples taken from different patches of products are representatives.
If the sample proves defective,the entire concerned is to be rejected or recovered.
Sampling inspection is cheaper and quicker.It requires less number of Inspectors.
It is subjected to sampling errors but the magnitude of sampling error can be estimated.
In the case of destructive test,random or sampling inspection is desirable.
This type of inspection governs wide currency due to the introduction of automatic machines or equipments which are less susceptible to chance variable and hence require less inspection,suitable for inspection of products which have less precision importance and are less costly.
Example: Electrical bulbs,radio bulbs,washing machine etc.
