Usually there are three kinds of QC Inspection: Pre-production QC Inspection, During-production QC Inspection and Pre-shipment QC Inspection.
Pre-production inspection:
This type of inspection is necessary if you want to check the raw materials or components that will be used in production. Buying cheaper materials can increase a factory’s margin considerably, so you should keep an eye on this risk. A pre-production inspection might also be a good idea if you suspect that technicians on the factory floor have not been given all the information or have not understood all your requirements.
At the beginning of the production process, do a visual check on the quality of components, materials, accessories, semi-finished and finished products against client specifications and/or reference samples, to predict any possible problems and make recommendations, and so as to verify that your product specifications are being met early
During production inspection:
Send an inspector during production, always check the following aspects:
•The production status during the manufacturing process
•The semi-finished and finished products at random
•The production lines & capability
•The package details and packing material
You can get a good idea of the average product quality, and be able to ask for corrections if problems are found. It can take place as soon as the first finished products get off the line, but these samples might not be representative of the whole order. So usually such an inspection is done after 10-30% of the products are finished. What you benefit from this?
•Be aware of quality issues early, and implement corrective actions before it is too late
•Communicate with your supplier about what is acceptable and what is not
•Get a precise production schedule