A greater understanding of quality control, types of quality control, Quality inspection, Elements of quality inspection and Quality inspection planning
2. What is Quality Control?
This may be defined as measures put in place in order to ensure that the product
meets the customer expectations
Those planned and systematic actions which provides a mean to control and
measure the characteristics of a product, process or a service to established
requirements
Quality control monitors not only the product itself, but the way it is produced,
stored and transported
3. Why is quality control important?
The manufacturing process is a repetitive process depending on both controllable
and non controllable factors resulting in the deviation of the quality of the product.
Quality control is the vital process for verification or correction of the quality of the
product whenever the deviations are found to be more than expected.
4. Types of Quality Control
Internal quality control - When a company institutes protocol to check their system,
this is called internal quality control. This can range from routine checking of
equipment, having a co-worker go over another employee's data analysis, or running
standards and controls on a regular basis. It is generally up to management to decide
if internal quality control measures are reliable and performed as needed
External Quality Control – This is when data or products are sent to an independent
body from the company e.g sending food to the Food and Drug administration.
Proficiency Testing Quality Control - A special type of quality control often done on
a volunteer basis or to gain accreditation is proficiency testing. In this type of quality
control, the company is sent a series of tests to perform. The results are sent back and
the company receives a grade on its proficiency. This type of testing is often done in
laboratories, where sensitive equipment and complex protocols need to be verified as
accurate before the lab is allowed to continue its work.
5. What is Quality Inspection?
The ISO standard defined inspection as the activity of measuring, examining,
testing one or more characteristics of the product/service and comparing the
results with the specified requirements in order to establish whether conformity is
achieved for each characteristic.
This task is usually performed by specialized personnel and does not fall within the
responsibility of production workers.
Products that do not comply within the specifications are rejected or returned for
improvement.
7. Forms of Quality Inspection
Final Article inspection – This ensures that all design, Engineering, and specification requirements are
understood, accounted for and verified. It takes place right after the manufacturer starts producing the
first mass production samples
Incoming inspection - Gives the idea on which kind of raw materials (or components) are to be used.
Factories are often suspected of lowering their costs by purchasing substandard materials, and this can be
disastrous for the company(e.g. the wrong kind of chip in an electronic device).
During production - allows the buyer to have an idea of average product quality, early in the production
cycle. It usually takes place once some finished products have come out of the lines. If quality issues are
found, what is already produced might be re-workable, and corrective actions can be taken for the rest of
the job.
Final Inspection - It takes place once 100% of shipment quantity is finished and at least 80% is packed, so
it can be a real random inspection.
Container loading inspection- This is done to ensure that the right kind of products are shipped out in the
right quantity, when the importer places no trust in his supplier or when several suppliers bring their
products for consolidation.
“Go and no go” inspection -
8. Elements of inspection
Intepretation of quality requirements
Sampling
Examination
Decision and action
9. Quality Inspection tools
These are tools used by inspectors to ensure that all the products manufactured by the
company are within the limits designated by the designers/producers.
Examples of such tools include ;
Air gages(inside and outside diameter, to look for leaks)
Bore gages (to measure dimensions)
Calipers (slide movement
Color sensors (determine the proper color mixture of clothing or textile)
Biological Microscopes(to study organisms and their vital processes)
Electron Microscopes (to produce smaller scale images of the product)
3-D scanners
10. Quality Inspection planning
A quality control plan is a document that provides instructions on how an
inspection of a product is to take place.
Inspection plans provide details about what characteristics must be tested in order
to ensure the quality of the product, as well as specific metrics and measurements
that must be achieved in order for the product to be judged in compliance with
standards.
11. Types of Inspection Plans
Plan Type Used to Collect Data and Report On
Receiving Items received at the warehouse
Resource Equipment or machinery in Shop Floor
Inventory Items in your inventory
Work in Process Work order execution
12. Inspection plans (cont’d
Inspection Plan Type Inspection Criteria
Receiving inspection plans •Suppliers and supplier locations for the
document type: Purchase order
•Source organization for document types:
In-transit shipment, Return material
authorization, and Transfer order
Inventory inspection plans Subinventory and locators
Work in Process inspection plans Operation Code or Operation Sequence or
both along with the Dispatch Status