Input-process-output (I-P-O) is a structured methodology ... It is often referred to, interchangeably, as an I-P-O model or an I-P-O diagram, both of which refer to the intended visual nature ...

A key process input variable (KPIV) is a process input that provides a significant impact on the output variation of a process or a system, or on the key process output variable (KPOV) of a product.