Risk Analysis Methods (Severity)

In a qualitative approach, risks are usually categorized into “high”, “medium” and “low”, and are represented in a risk matrix. This risk matrix represents the possibility and severity in order to integrate the potential accident scenarios that were identified in the threat identification stage. Inside the matrix, the criticality of a risk, through the use of colors, can identified. The results provided by this matrix can be used to compare risks and identify improvement and mitigation measures.

The preliminary hazard analysis (PHA) is a semi-quantitative risk analysis methods that is used to identify potential hazards and the corresponding top events (risks). The PHA sheet identifies as well the required measures and follow-up actions to control the hazard sources. The PHA should consider hazardous components, facilities, safety-related equipment, and environmental constraints.

The Monte Carlo simulation is one of the stochastic simulation methods in which random numbers are used within certain ranges for the calculation of the scenarios. To estimate risks or decisions under uncertainty, stochastic and dynamic methods are almost exclusively used today. With the help of Monte Carlo simulation, the impact of different decisions and their probability of occurrence can be estimated using synthetic data. It is a calculation method to simulate extreme cases, but also to secure everyday decisions. This makes it usable for a wide variety of industries.

The hazard diamond is used to identify and analyze the different risks associated with hazard sources. The hazard diamond or the so-called fire diamond is defined in the NFPA (704) which is the Standard System for the Identification of the Hazards of Materials for Emergency Response. The four divisions of the diamond are color-coded to represent flammability (red), health hazard (blue), chemical reactivity (yellow) and special hazards (white).The Hazard diamond is normally used to identify the risk associated with hazardous materials and dangerous goods.

The Failure Mode and Effects Analysis is a cross-industry established method to identify and eliminate potential failures, problems, errors and risks of a system, design or process before adverse consequences reach the internal/external customers. The basic idea of the FMEA is thus the preventive risk identification and error prevention instead of a subsequent correction.