What is the correct definition of "good manufacturing practice (GMP)"?

In practice it is difficult to locate a satisfactory scientific working definition of GMP. CODEX does not use the expression GMP but rather refers to Codes of Practice. GMP may be defined as that part of a food control operation aimed at ensuring that products are consistently manufactured to a specified quality appropriate to their intended use. It thus has two complementary and interacting components; the manufacturing operation itself and the control system and procedures. (IFST, 1998)