Of course, it depends on each buyer’s needs. List some quality control plan below, for inspiration.

Timing of inspections
the buyer reserves the right to send of of his employees/representatives in the factory to inspect production at anytime.

Communication of status of production
the supplier should send an email to the buyer 3 days before it receives the main materials/components, and should send a confirmation email on the day they arrive in the factory’s warehouse.
the supplier should send an email to the buyer 3 days before the factory starts working on its order, and should send a confirmation email on the same day it happens.
the supplier should send an email to the buyer 3 days before the first finished products are out of the lines (i.e. fully produced), and should send a confirmation email on the same day it happens.
the supplier should send an email to the buyer 3 days before 100% of the shipment quantity is finished and 80% is fully packed (i.e. ready to ship), and should send a confirmation email on the same day it happens.
the supplier should sent an email to the buyer every time some samples are sent to a laboratory for testing.

Description of quality control activities
the buyer reserves the right to perform the following quality control activities, and any other activity not described below.

Product inspections: random inspections of products, conducted based on the ISO2859-1 standard (single plan, normal level). Acceptable quality level (AQL) is 0% for critical defects, 2.5% for major defects, 4.0% for minor defects.

Lab tests: B will have to send 2 samples to ABC laboratory for XYZ tests, in order to respect the consumer safety law of the importing country. These samples must be extracted from bulk production. the buyer may, or may not, ask the inspector to pick these samples.