A Retrospective Validation method for drug manufacturing computerized system using Programmable Logic Controller

This paper proposes Retrospective Validation method for working Programmable-Logic-Controller based Computerized System. The proposed method consists of three solutions; (1) clarify a validation concept for computerized system that is developed by combining several different categories, (2) Clarify risk reduction measures into four types (task, program, structure, and hardware modification), and (3) Define detailed RCSV procedure depending on the current status of PBCS and development documents. As a result of application, we found that the proposed method reduce the 20% working time and develop adequate validation documents.