.1 Object of this standard This standard establishes requirements for the whole life cycle of operating procedures that the designer wishes to computerise. It also provides guidance for making decisions about which types of procedures should be computerised and to what extent. Once computerised, procedures are designated as "computer-based procedures" (CBP). 1.2 Context leading to development and use of CPB Enhancing safety, easing operation and increasing NPP availability have always been greatly valued aims which, during NPP operation, rely to a large extent on the operating staff and on operating procedures. Digital technology contributes not only by providing efficient ways of automating key functions but also enhances instrumentation, control and the plant’s HMI. In addition, the use of computer technology to provide formats of operating procedures to the plant operators1, on-line and in real time, is increasing and becoming current practice. This can be done both for normal operating situations and also as advisory formats for use in abnormal situations. When properly implemented and kept up-to-date, such operating procedures can provide enhanced support for greater safety and operator effectiveness compared to paper-based procedures. Their preparation demands great care and close interaction with operators and plant designers, and will also need close co-operation with I&C designers. CBP have many common points with paper-based procedures. This standard focuses only on what is specific to CBP.