What are the four types of quality assurance?
The four types of quality assurance are pre-production inspection (PPI), during production inspection (DPI), pre-shipment inspection (PSI), and container loading/loading supervision (LS).
The PPI or pre-production inspection is conducted prior to the production process begins. It aims to help assess the quantity and quality of the raw materials and components and whether they conform to the relevant product specifications.
A PPI inspection is important as it can help reduce or eliminate communication between you and your supplier regarding production timelines, shipping dates, and quality expectations.
The During Production Inspection (DPI) is a quality control inspection conducted while production is already underway. This step is useful for products in continuous production with strict requirements and when quality issues have been found before manufacturing during an earlier PPI.
The DPI inspections typically only occur when only 10-15% of units are completed. Any deviations can be identified, have feedback given, and any defects can be re-checked to confirm they have been corrected.
The PSI or post shipping inspection is an important step in the quality control process. It’s the primary method for checking the quality of goods before they are shipped. PSI ensures that production complies with the specifications of the buyer.
This inspection process is conducted on finished products when at least 80% of the order has been packed for shipping. Typically, random samples are selected and inspected for defects against the relevant standards and procedures.
