In the most general sense, validation refers to a process that consists of at least four distinct components or steps: software, instruments, methods or procedures, and system suitability . The system, the software, and the method must all be validated, and system suitability is used to keep the process in check. But while the overall process is called validation, some of the steps also are referred to by that same term, as well as other steps such as qualification and verification.
Instruments are qualified according to a stepwise process grouped into four phases: design qualification (DQ), installation qualification (IQ), operational qualification (OQ), and performance qualification (PQ), as outlined in Table I, reproduced here from the USP . Another way of looking at the AIQ process is sometimes referred to as a time-line approach; as presented in Figure 1, a true chronological order of events takes place