A Study of Computerized System Validation Method for PLC Based System

This paper proposes validation methods for Computerized Systems (CS) that control drug manufacturing equipment built using a Programmable Logic Controller (PLC). This is called CS Validation (CSV). CSV is a process to prove adequacy for functions and performance of such CS by giving development and verification documents. However, Any CSV standards do not describe details about the implementation of CSV for CS with complicated functional structures. Given that, this paper standardizes the functional structures of such CS. And, this paper proposes the CSV procedures in the development and modification stages. In addition, some CSV support tools, such as the design information database and requirements trace tool, are developed. The application of the proposed CS classification methods, CSV procedures, and the support tools confirmed that working hours for CSV in the developmental stage improved by 20%, while working hours in the modification stage improved by 29%. Moreover, the quality of the documents related for development and verification that are created when implementing CSV is conducted were also improved.