In engineering, quality control (QC) is a management function that regulates the quality of raw materials, assemblies, products and components; services related to production; and management, production, and inspection processes. Its goal is to prevent faulty products or services from leaving the organisation.
... coast, and Tertiary conglomerates, sandstones, marls and clays, folded by subsequent upheavals, in many parts of the island. The clays, which contain layers of good coal ...