MHK ISDB/Tests/Risk Assessment/Risk Assessment Overview
Risk Assessment: Risk Assessment Overview
A thorough risk assessment and development of risk mitigation plans prior to deployment will help maximize the potential for test success and minimize potential personnel, environmental and fiscal harm. Safety is paramount: general safety targets need to be set and all hazardous operations need to have approved Safe Operating Plans (SOPs). This summary leverages the work done by the American Petroleum Institute.
Overview for Open Ocean Testing
1. Risk Assessment and Consequence Analysis
- Hazardous events can arise at any time during the use of a marine energy converter (during mobilization, installation, operation, repair and recover) that may result in injury or fatality, damage to the environment and damage to property. Risk assessments are therefore recommended to help identify and mitigate risk that may occur over the life of a test – from mobilization through deployment and system recovery/decommissioning. The following methodology summarizes procedures commonly used in the offshore oil and gas and land based wind for risk assessment. The goal is, by understanding the risks, appropriate mitigation measures and plans can be developed to maintain risk within acceptable levels. Knowledge provided by risk assessments help to inform decisions about how to deal with those risks. The steps outlined in this section provide a brief guide to evaluate and categorize risk based on probability and severity. References are provided at the end of this section that provide more detail and guidance on performing risk assessments and consequence analysis.
2. Hazard Identification (HAZID)
- Hazard Identification (HAZID) studies are used to identify the project risks that impact person, property or the environment. These can be a result of a failure, an operation or intervention, unintended action, or external event (such as a collision with a vessel) that have a direct impact or can initiate a chain of events. These hazards can be identified from past history of the device under test or similar devices, brain storming what-if scenarios, Failure Modes and Effects Analysis (FMEA), among many other techniques. The references provided at the end of this section provide much more detail.
3. Probability Assessment
- This aims to determine the probability of an event or a sequence of events will occur leading to hazard. Quantitative estimates can be obtained by using data bases of historic failure rates (provided by manufacturer for example), fault tree analysis (FTA) and other methods for reliability analysis. When historic numbers are not available, fatigue analyses can be used and best judgment is also acceptable when no other alternative is available. As part of this analysis, site specific data should be considered, such as the occurrence and size of storms.
4. Consequence Assessment
- Consequence assessment quantifies the range of possible outcomes that may result from the hazard event. Consequences are typically evaluated from a financial loss, injury and loss of life, and environmental and property damage perspectives. This can be done from both qualitative and quantitative standpoints. Damages can often extend beyond the incident itself and affect the whole industry, consider the BP Deepwater horizon and the impact to the offshore oil and gas industry.
5. Risk Evaluation
- The overall Risk of a hazard is typically evaluated with a Risk matrix that plots the frequency of the Hazard against the severity of the consequence. As part of this analysis, levels of risk must be defined as acceptable and unacceptable or via a rating scale. Typically, the higher the risk, the more mitigation effort is required. The highest risks often require redesign while moderate risks can be handled through pragmatic measures.
- API RP 2FPS, Recommended practices for planning, designing, and constructing floating production systems, March 2001