ELICITATION OF SAFETY REQUIREMENTS FOR PROCESS AUTOMATION

This paper introduces an elicitation methodology for safety requirements in process automation. The requirements arising from the functional and other technical characteristics of the process have been considered rather than the standards and the guidelines related to a specific process or country. The methodology is based on discussions between automation and process engineers, in which the potential hazards of the process are identified. Knowledge about the chemical substances handled in the process and about the process conditions is used for this purpose. The possible process disturbances and accident sequences are identified using a Unit Level HazOp methodology. Classification of risks has been made based on the probability of the causes and consequences of the hazards and on the criticality of the consequences. The methodology helps the designer identify the most critical process parameters and suggest control and protective actions to keep the process safe.