Safety and Risk
- Safety is the freedom from risk. If you want to increase safety, you must first consider risk. Risk is the “probability or threat of damage, injury, liability or loss, or any other negative occurrence that is caused by external or internal vulnerabilities, and that may be avoided by preemptive action”
Individual Risk
- The frequency at which an individual may be expected to sustain a given level of harm from the realization of specified hazards
Social Risk
- The frequency with which a specified number of people in a given population, or population as a whole, sustain a specified level of harm from the realization of specified hazards
As Low as Reasonably Practicable
- ALARP, which stands for "as low as reasonably practicable", or ALARA, is a term often used in the regulation and management of safety-critical and safety-involved systems. The ALARP principle is that the residual risk shall be reduced as far as reasonably practicable.
- usually applied to risks in some areas as radiation protection and chemical accident prevention, preparedness and response that fall below a defined level of “intolerable” risk. This principle recognizes that not all risks can be eliminated; there will be always a residual risk of an accident since it may not be practicable to take further actions to reduce the risk or to identify the potential accidents.
Risk assessment
- a risk assessment is the combined effort of: identifying and analyzing potential events that may negatively impact individuals, assets, and/or the environment; and making judgments "on the tolerability of the risk on the basis of a risk analysis" while considering influencing factors.
- technical estimation of the nature and magnitude of a risk. It involves basically the answers to three questions: What can go wrong? How frequently does it happen? What are the consequences?
Event Tree Analysis
- Event tree analysis is a forward, top-down, logical modeling technique for both success and failure that explores responses through a single initiating event and lays a path for assessing probabilities of the outcomes and overall system analysis.
- a technique that uses a graphical logic model that identifies and quantifies possible outcomes following an initiating event.
Preliminary Hazard Analysis
- The Preliminary Hazard Analysis (PHA) is usually the first attempt in the system safety process to identify and categorize hazards or potential hazards associated with the operation of a proposed system, process, or procedure.
- a method designed to recognize early hazards and focuses on hazardous materials and major plant systems during the early stages of life-cycle of the plant, when only few details on the plant design and possibly no information about plant procedures may be available.
Hazard and Operability Study
- Hazard and Operability Study (HAZOP) is a structured and systematic examination of a complex planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment. It is also used as the basis for reviewing batch processes and operating procedures.
- a systematic procedure for identifying potential hazards and operability problems. The HAZOP procedure makes systematically questions over every part of a system to discover how deviations from the design intent can occur. The consequences of these deviations are then determined and, if significant, remedial actions are recommended.
Availability
- is the probability that the system is operating satisfactorily at any time, and it depends on both reliability and maintainability
Human Reliability Assessment
- Human Reliability Assessment (HRA) is a method that involves systematic prediction of potential human errors when interacting with a system. Once they are identified, actions are suggested to try eliminating or reducing their occurrence probabilities, in order to maximize safety and performance of the system or facility.
