Clause 8.2.4 Monitoring and measurement of product

A fourth source of information is based on measurements of characteristics of the product (inspection and tests). This may be a verification of quality, dimensions, weight, thickness, hardness, etc. Basically, it covers any activity that determines whether something is acceptable.

Each individual organization needs to decide where these inspections and tests should be carried out. The general rule is that they should be performed at critical stages of processes. Typically, this is the case when a product is passed on a next production stage or when there is a substantial risk of errors or deficiencies. A car manufacturer will want to perform several in-process inspections and inspections of parts because without these inspections a deficiency may not be detected later, or it may be very costly to correct it.

Similarly, the types of inspections or tests performed should be dependent on the critical nature of the product or the process. In some cases, such as a distributor receiving bearings, an inspection may be as simple as checking the type and number of bearings received.

Inspections of final products are always critical because there will not be opportunity to correct any deficiencies after this point (unless it is not possible to perform a full final inspection) . In performing inspection and testing, 100% of the product does not have to be tested. There are many products made where a sampling procedure is used and the batch passed or rejected on the basis of the sample. The subsequent detection of nonconforming product (see 8.3) does not mean that the sampling procedure is incorrect. However, a continuing and perhaps higher than expected level of nonconformities may suggest that the sampling plan or procedure needs to be investigated.

Obviously an inspection or test is only useful if the acceptance criteria are known. The result of the inspection or test is either a pass or a fail, based on these acceptance criteria. Preferably, acceptance criteria should be measurable (such as in dimensions or quantities), but they can also be subjective, for example, criteria for visual inspection or taste tests.

The result of inspection and tests need to be recorded. Examples of inspection records are checklists, pick tickets, job cards, or work orders. In any case, it is wise to use the records that are already in use by the organization as much as possible. For example, in small machine shops with only a few employees, it is common practice for machine operators to inspect their own work before passing it on to the next machine station. Consecutive operators sign a job card as it follows the work in progress. This is a good practice because the work of the next operator down the line is affected if the incoming work is not correct. Also, the next operator can check the previous operator's work.

The record should clearly state who performed the inspection and what the result of the inspection was (i.e. pass or fail)
If an inspection or test needs to be performed, then product should not proceed to the next activity or production stage until the inspection or test has been completed with positive results. A product can only be released without inspection or tests if there is an approval from the relevant authority within the organization or from the customer.

Develop a quality plan or inspection and testing plan for entire product realization cycle (refer 7.1) step by step and identify inspection and tests requirements at each stage giving details like description of test, reference document, methodology, acceptance criteria, sampling plan, involvement of various agencies like customer, third party, responsibilities and authorities for relating to product acceptance (rejection, nonconformity control) etc.

This plan can be made once for standard products or for each project and contract, as may be required based on type of your product, contract. Ensure that quality plan or inspection and testing plan is implemented as per its objective.

External Document Reference: Documentation Kit

Quality Plan Sample
Product Specification Sample
Inspection Report Sample

Additional Key words: inspection and testing, receiving inspection, in-process inspection, final inspection, process inspection, rejection, scrap, recycle, production cycle, manufacturing cycle, quality plan, quality planning