1、 GUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES JUNE 2003 American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 Copyright 2003 American Bureau of Shipping ABS Plaza 16855 Northchase Drive Houston, TX 77060 USA ABS GUIDE FOR RISK
2、EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES .2003 iii Foreword The mission of the American Bureau of Shipping (ABS) is to serve the public interest, as well as the needs of its clients, by promoting the security of life, property, and the natural environment primarily through the
3、 development and verification of standards for the design, construction and operational maintenance of marine-related facilities. The Rules on which classification is predicated are established from principles of naval architecture, marine engineering and other engineering principles that have prove
4、n satisfactory by service experience and systematic analysis. The perceived benefits of the deterministic and prescriptive regulatory requirements were based mostly on experience, testing programs and expert judgment. The objective of these Rules has always been to ensure that the probabilities of a
5、ccidents with the potential for adversely affecting life, property and the natural environment are low. However, this assurance was not explicit, as Rules and regulations until recently were developed without the benefit of explicit estimates of risk. In recent years, there have been significant adv
6、ances in and experience with risk assessment methodology. ABS is continually seeking the improvement of its Rules and methods of analysis and exploring the directions where the industry is headed. Thus, ABS is exploring certain changes to the development and implementation of its Rules and regulatio
7、ns through the use of risk-based, and ultimately performance-based, approaches. The rewards for this potential process are improved classification services and, ultimately and foremost, improved safety and productivity. The transition to a risk-based regulatory framework is expected to be incrementa
8、l. Many of the present requirements are based on deterministic and prescriptive requirements that cannot be quickly replaced. Therefore, the current requirements will have to be maintained, while risk-based and/or performance-based approaches are being developed and implemented. The information and
9、process outlined in this Guide provides a risk-based perspective to evaluating proposed designs that offer alternative means of compliance to current prescriptive requirements, or novel designs for which classification requirements do not exist. This perspective offers many advantages to ship owners
10、/designers and ABS. Some of these advantages are: i) Increased ability to suggest innovative designs that are technically superior and more cost-effective. ii) Increased confidence that the proposed designs will provide the same level of safety. iii) Better understanding of hazards, mitigation measu
11、res, and risk posed by the proposed design. The process defined in this Guide provides a sound and practical approach for performing risk-evaluations to support the classification of proposed designs, so that the advantages listed above can be realized. This document provides guidance on how to prep
12、are a risk-based submittal to demonstrate that a proposed design meets the overall safety and strength standards of the Rules. It defines a process that the client can implement to prepare and submit documentation for consideration by ABS. It also outlines the approach that ABS will take in reviewin
13、g the submittal to determine if the proposed design is acceptable for classification. Additional guidance will be published on the application of risk-based approaches to classification activities, such as the ABS Guidance Notes on Review and Approval of Novel Concepts, the ABS Guide for Surveys Usi
14、ng Risk Based Inspection Techniques, and the ABS Guide for Surveys Based on Reliability Centered-Maintenance. ABS GUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES .2003 v GUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES CONTENTS SECTION 1 G
15、eneral1 1 Objective 1 2 Application .1 3 Definitions 1 SECTION 2 Concept of Equivalency 3 1 General 3 2 Evaluation Metrics3 3 Evaluation of Alternative Arrangements 4 4 Evaluation of Novel Features.4 5 Acceptance Criteria5 SECTION 3 Risk Evaluation Process .7 1 General 7 FIGURE 1 Risk Evaluation Pro
16、cess 8 SECTION 4 Evaluation Objectives9 1 General 9 2 Selection of Evaluation Metrics9 3 Comparative versus Absolute Assessment .10 3.1 Comparative Risk Assessment .10 3.2 Absolute Risk Assessment10 SECTION 5 Basic Risk Assessment.11 1 General 11 2 Development of Basic Risk Assessment Plan.12 2.1 Se
17、lection of Risk Assessment Technique .12 2.2 Establishment of Acceptance Criteria .13 2.3 Scope of the Risk Assessment13 vi ABSGUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES .2003 3 Performance of the Basic Risk Assessment14 3.1 Identifying the Risk Analysis Team14 3.
18、2 Preparing for the Risk Assessment .14 3.3 Hazard Analysis 14 3.4 Estimation of the Evaluation Metrics .15 3.5 Comparative Assessments and the Change Analysis Method 15 4 Evaluation of Results of the Basic Risk Assessment 16 4.1 Evaluation of Comparative Risk Assessment16 4.2 Evaluation of Absolute
19、 Risk Assessment 16 4.3 Confidence of the Results .16 5 Documentation of Basic Risk Assessment 17 6 Use of an Existing Risk Model .17 6.1 General17 6.2 Appropriateness of Model17 6.3 Risk Impact18 FIGURE 1 Risk Matrix Concept.13 SECTION 6 Detailed Risk Assessment 19 1 General 19 2 Development of Det
20、ailed Risk Assessment Plan 20 2.1 Selection of a Risk Assessment Technique.20 2.2 Establishment of the Acceptance Criteria21 2.3 Scoping of the Risk Assessment .22 3 Performance of the Detailed Risk Assessment .22 4 Evaluation of Results of the Detailed Risk Assessment22 5 Documentation of the Detai
21、led Risk Assessment22 SECTION 7 Submittals to ABS 23 1 General 23 2 Prior to Conducting Risk Assessments23 2.1 Risk Assessment Plan.23 3 Basic Risk Assessment Submittal Requirements24 4 Detailed Risk Assessment Submittal Requirements .24 5 Review/Approval of Submittals 25 6 Life Cycle Risk Managemen
22、t .25 APPENDIX 1 References 27 APPENDIX 2 Risk Analysis Team . 29 1 Overview of the Risk Analysis Team .29 1.1 Team Leader .29 1.2 Scribe 29 1.3 Subject Matter Experts 30 ABS GUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES .2003 vii APPENDIX 3 ABS Risk Models31 1 Overv
23、iew of ABS Risk Models .31 TABLE 1 Tanker Model General Design Assumptions .31 TABLE 2 FPSO Model General Design Assumptions.31 TABLE 3 Risk Model Consequences 32 APPENDIX 4 Overview of Risk Assessment Techniques .33 1 Hazard Identification (HAZID) Technique33 2 Change Analysis Methodology 33 2.1 Ty
24、pical Analysis Activities for Change Analyses .34 3 What-if Analysis .36 3.1 Typical Analysis Activities for What-if Analyses 36 4 Checklist Analysis37 4.1 Typical Analysis Activities for Checklist Analyses .38 5 Hazard and Operability (HAZOP) Analysis39 5.1 Typical Analysis Activities for HAZOP Ana
25、lyses .40 6 Failure Modes and Effects Analysis (FMEA) .41 6.1 Typical Analysis Activities for FMEAs .42 7 Event Tree Analysis.44 7.1 Typical Analysis Activities for Event Tree Analysis .44 8 Fault Tree Analysis 45 8.1 Typical Analysis Activities for Fault Tree Analysis.45 9 Summary of Key Aspects of
26、 Risk Assessment Techniques 47 10 Additional Literature Resources.49 TABLE 1 Example Change Analysis.35 TABLE 2 What-if Evaluation Example.37 TABLE 3 Checklist Analysis Example.39 TABLE 4 Example of a HAZOP Analysis 41 TABLE 5 FMEA Evaluation Example 43 TABLE 6 Overview of Commonly Used Risk Assessm
27、ent Techniques.48 FIGURE 1 Example Event Tree Analysis45 FIGURE 2 Example Fault Tree Analysis .47 APPENDIX 5 Survey of the Use of Risk Acceptance Criteria .51 1 US Offshore Oil Production Industry51 2 US Coast Guard (USCG).52 3 US Nuclear Regulatory Commission (NRC)56 4 US Department of Defense (DOD
28、) 58 viii ABSGUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES .2003 5 US Department of Energy (DOE) 60 6 United Kingdom Health and Safety Executive.62 7 International Maritime Organization (IMO).64 TABLE 1 Risk Assessment Code Levels and Recommended Response Criteria 55
29、 TABLE 2 U.S. Department of Energy Risk Matrix with Risk Goals Consequence versus Frequency.61 TABLE 3 Chemical Accident Consequence Levels 61 TABLE 4 Example Radiological Accident Consequence Levels.61 FIGURE 1 USCG Frequency/Consequence Categories and Risk Screening Criteria 54 FIGURE 2 Blank Risk
30、 Matrix with RACs .54 FIGURE 3 Example Risk Profile56 FIGURE 4 MIL-STD-882D Risk Matrix59 FIGURE 5 Risk Tolerance Distribution within Risk Matrix (MIL-STD-882D).60 FIGURE 6 IMO Formal Safety Assessment (FSA) Process65 ABS GUIDE FOR RISK EVALUATIONS FOR THE CLASSIFICATION OF MARINE-RELATED FACILITIES
31、 .2003 1 SECTION 1 General 1 Objective This document provides guidance to ABS clients on how to prepare a risk evaluation to demonstrate that a design proposed for classification meets the overall criteria for safety and strength standards of the ABS Rules and Guides. It defines a process that the c
32、lient can implement to prepare and submit documentation for consideration by ABS. It also outlines the approach that ABS will take in reviewing the submittal to determine if the proposed design is acceptable for classification. 2 Application This document applies to any situation where a design is b
33、eing proposed on the premise that it provides equivalent protection against the risks addressed by the ABS Class Rules, rather than by strict compliance with existing prescriptive classification Rules. Evaluations of hardware and survey issues are included in the scope of this document. This Guide i
34、s applicable to both ships and offshore facilities. Specifically, this Guide is applicable when ABS clients are proposing: i) Alternative Arrangements. Marine-related facilities with design characteristics that include alternative means of compliance to applicable prescriptive classification Rules.
35、ii) Novel Features. Marine-related facilities that contain novel features of design in respect to the hull, machinery, or equipment to which provisions of the Rules are not directly applicable. A special comment will be entered in the Record indicating that classification of the vessel/installation
36、has incorporated the provisions of this Guide. If proposed designs include alternative arrangements or novel features that conflict with existing applicable statutory requirements or regulations from any other regulatory body outside ABS, the decision for approval lies with those external bodies. Wh
37、ile many regulatory bodies are evolving to accept the use of risk evaluations to demonstrate safety equivalency to prescriptive requirements, there may always be a number of regulatory bodies that will not accept such flexibility. The cognizant administration or regulatory body is the final determin
38、ing body for statutory or regulatory requirements under their jurisdiction. Note that if a proposed design is categorized as a Novel Concept according to the application scope defined in the ABS Guidance Notes on Review and Approval of Novel Concepts, then those Guidance Notes should be followed, un
39、less otherwise instructed by ABS. 3 Definitions Absolute Risk is the expression of risk in terms of the specific estimates of the frequency and consequence. Acceptable Risk is the expected risk that is considered tolerable for a given activity. Section 1 General 2 ABSGUIDE FOR RISK EVALUATIONS FOR T
40、HE CLASSIFICATION OF MARINE-RELATED FACILITIES .2003 Analysis Team is a team of the subject matter experts and risk analyst(s) who are responsible for performing the risk assessment. Change Analysis is a comparative risk assessment technique that logically identifies risk impacts and risk management
41、 strategies in situations where change is occurring. Confidence is the analysts/teams certainty of the risk evaluation. Consequence is an unwanted event that can negatively affect subjects of interest. It can be expressed as number of people affected (injured or killed), property damage, amount of a
42、 spill, area affected, outage time, mission delay, dollars lost or other measure of negative impact. Direct Design is a design that results from the direct application of the ABS Rules or Guides. Evaluation Metrics are qualitative and/or quantitative parameters selected to characterize or evaluate a
43、 proposed design in terms of its level of safety, that are used to judge the adequacy of the proposed design for classification. The evaluation metrics could be directly a risk measure (e.g. fatalities per year), but it could also be any one component that affects risk. Examples of evaluation metric
44、s are: the reliability of a system, the frequency of loss of propulsion events, the number of safeguards available to mitigate a fire in a specific location, etc. Event is an occurrence that has an associated outcome. There are typically a number of potential outcomes from any one initial event that
45、 may range in severity from trivial to catastrophic, depending upon other conditions and subsequent events. Frequency is the expected number of occurrences of an undesirable event expressed as events per unit time. Hazards are conditions that exist that may potentially lead to an undesirable event.
46、Major Hazard is a hazard with potentially unacceptable risk if not eliminated, controlled, and/or managed. Chapters 4 and 5 of ABSs Guidance Notes on Risk Assessment Application for the Marine and Offshore Oil and Gas Industries provide a list of major hazards. Qualitative Risk Assessment is a risk
47、assessment that expresses the risk in terms of quality or kind (e.g., low, high, very high). Quantitative Risk Assessment is a risk assessment that expresses the risk in terms of risk impact per unit time (e.g., $1,000,000 per year). Relative Risk is the expression of the change in risk relative to
48、a case of interest or baseline case. Risk is the product of frequency with which an undesirable event is anticipated to occur and the consequence of the events outcome. Risk Analysis is the process of understanding (1) what undesirable things can happen, (2) how likely they are to happen, and (3) ho
49、w severe the effects may be. More precisely, it is an integrated array of analytical techniques, e.g. reliability, availability and maintainability engineering, statistics, decision theory, systems engineering, human behavior, that can successfully integrate diverse aspects of design and operation in order to assess risk. Risk Assessment includes a risk analysis, but it also involves the process by which the results from risk analysis are considered against judgment, standards or criteria. Safety Margin is an adjustment made to compensate for the uncertainties and assumptions used in the
