Risk Assessment and Calibration of Risk Matrices Aspects

Abstract

Modern quality management systems, including ISO 9001 standard based, are widely used by companies. Availability of ISO 9001 certificate and quality management system, that runs like well-lubricated machine, gives the company the tool to concentrate on customer needs, to keep the high quality standard of all processes in the company, to collaborate with reliable partners and as a result to offer the high quality products and services. There is a tendency that management systems are becoming more risk thinking based and refer to risk management standard ISO 31000. Risk management standard stands for managing risks with consequences related to safety, economic performance, environmental and other outcomes thus support company continuous improvement.For machine industry risk assessment is crucial as this is a part of CE marking documentation. According to EU legislation, to sell the machinery within European Economic Area, CE marking of machines showing the machine correspondance to Machinery directive requirements is mandatory. Risk assessment in machine industry is applied for evaluation of the risks associated with corresponding hazards to guarantee the safety of design, production process and machinery produced. Risk assessment is conducted to evaluate machine design, exploitation or manufacturing process risks. For production process risk estimation the risk levels of subprocesses should be considered.There are no available risk assessment industry standards. Risk matrices developed by companies are used to analyse and estimate risks for correct decision making and risk reduction. Unfortunately faulty risk matrices cause difficulties during risk estimation process and lead to inappropriate safety measures application. Risk matrices use numerical values and consider minimally hazardous event severity and probability of hazardous event levels. Numerical values of risk levels are listed in the risk matrices during risk assessment. Unfortunately calibration information with defined numerical risk tolerance criteria is often missing. Miscalibrated risk matrices lead to critically wrong decisions on risk elimination issues. This paper describes the aspects of risk matrices calibration and highlights the importance of risk tolerance definition applied during risk assessment.