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KR-102961877-B1 - A Developed Risk Assessment Methodology based on Formal Safety Assessment for Marine Engine System

KR102961877B1KR 102961877 B1KR102961877 B1KR 102961877B1KR-102961877-B1

Abstract

The present invention relates to an enhanced risk assessment method based on the official safety assessment of marine engines. By utilizing an enhanced risk assessment method based on the official safety assessment of marine engines, which complements the uncertainty of the qualitative risk assessment to objectively and rationally assess the risk, the invention enables the objective and rational assessment of the risk of marine engines.

Inventors

  • 이원주
  • 여실중

Assignees

  • 국립한국해양대학교산학협력단

Dates

Publication Date
20260507
Application Date
20221202

Claims (15)

  1. A risk impact assessment table preparation step for a marine vessel engine system, wherein the system of the marine vessel engine is hierarchically structured into mission, function, system, and subsystem, and a risk impact assessment table for the marine vessel engine system is prepared by specifying items for failure signals, causes of failure, and opinions on the causes of failure regarding the said mission, function, system, and subsystem; A ranking determination step for adding detection levels to the risk impact assessment table prepared in the above risk impact assessment table preparation step, and determining risk rankings by deriving weights for the added detection levels; A formal safety evaluation step for evaluating formal safety regarding the risk ranking determined in the above ranking determination step; Includes, The above official safety assessment stage is, Risk identification stage for identifying risk factors, Risk analysis stage that quantifies and analyzes risk, Risk control plan preparation stage, which devises measures to control risk, A cost-benefit analysis step for analyzing the costs and benefits related to the implementation of the risk control measures identified in the above risk control measure preparation step, A risk assessment method further comprising a decision recommendation step for making a decision on the implementation of risk control measures based on the costs and benefits analyzed in the above cost-benefit analysis step.
  2. In paragraph 1, the step of preparing the risk impact assessment table is, A risk assessment method that further includes a risk ranking step for ranking risks using a risk matrix based on a qualitative assessment of severity and frequency.
  3. In paragraph 1, the ranking determination step is, A weight derivation step for deriving weights for risk factors, A decision matrix derivation step for deriving a decision matrix of the evaluation results for risk factors derived by the above weight derivation step, A measurement normalization step for normalizing the measurement values of risk factors evaluated by different scales in the decision matrix derived by the above decision matrix derivation step, A decision matrix calculation step for calculating a decision matrix by assigning weights to the measured values of risk factors normalized in the above measured value normalization step, A risk assessment method further comprising a relative proximity coefficient calculation step for calculating relative proximity coefficients of all risk factors according to the decision matrix calculated in the above decision matrix calculation step.
  4. delete
  5. In paragraph 3, the ranking determination step is, A risk assessment method in which the detection level of the risk impact assessment table in the above ranking determination step is modeled as a normalized fuzzy set in the shape of a triangle and derived by the following equation (1). Equation (1) (Here, is a fuzzy set within the universal set (X), is a membership function where each element x of X is associated with some real number in the interval [0, 1], is a fuzzy number modeled as a triangular, normalized fuzzy set, ? A triangular fuzzy number Definition of)
  6. In paragraph 1, the ranking determination step is, A risk assessment method in which weights are derived for the detection rate of the risk impact assessment table added in the ranking determination step above, and the risk ranking is determined by deriving the following equations (2) and (3) to determine the fuzzy multi-criteria decision problem for m alternatives and n decision criteria that the decision makers must select. Equation (2) Equation (3) (here, i = 1, …, m, j = 1, …, n, Alternatives to be selected (risk factors in the present invention), is a decision criterion (in the present invention, a risk factor), is the weight for each decision criterion of the decision maker)
  7. In paragraph 3, the above weight derivation step is Risk factors ( Weights for ) A risk assessment method that assumes it is measurable by positive triangular fuzzy numbers.
  8. In paragraph 3, the decision matrix derivation step is, Performance measures in multi-criteria decision-making problems Assuming that it can be measured by positive triangular fuzzy numbers, the risk factors of K experts Risk factors from the perspective Performance measure evaluated A risk assessment method that derives the total sum from the following equation (4). Equation (4)
  9. In paragraph 3, the above measurement normalization step is, A risk assessment method for deriving the following equations (6) and (7), which are fuzzy decision matrices, by the following equation (5) to normalize measurements evaluated by different scales in a multi-criteria decision problem. Equation (5) (Here, B and C are sets of gain criteria and cost criteria, respectively) Equation (6) Equation (7)
  10. In paragraph 3, the decision matrix calculation step is, A normalized fuzzy decision matrix in which different weights are assigned to each risk factor in the normalized fuzzy decision matrix calculated in the above measurement normalization step ( A risk assessment method that derives ) from the following equation (8). Equation (8) (Here, , i = 1, … , m, j = 1, … , n., is a risk factor Weights indicating importance)
  11. In item 10, the above decision matrix calculation step is, The above weighted normalized fuzzy decision matrix? Accordingly, the elements of the normalized positive triangular fuzzy number , ∀ A risk assessment method that calculates the fuzzy positive solution (FPIS*) and fuzzy negative solution (FNIS-) and derives them from the following equation (9). (9)
  12. In Clause 11, the decision matrix calculation step is, A risk assessment method that derives the distance from FPIS A* and FNIS A- for each alternative using n-dimensional Euclidean distance from the following equation (10). Equation (10) (here, i = 1, …, m, j = 1, …, n., Each alternative from FPIS A+ Distance from, Each alternative from FNIS A- Distance from)
  13. In paragraph 3, the above relative proximity coefficient calculation step is, A risk assessment method for deriving the relative proximity coefficient (CC) of each alternative (risk factor) from the following equation (11) in order to finally determine the priority of all risk factors. Equation (11) (Here, The other side And, The other side )
  14. In paragraph 1, the cost-benefit analysis step is, A risk assessment method derived from the following Equation 12, which is the Gross Cost of Averting a Fatality (GCAF) for measuring the degree of cost-effectiveness of the above-mentioned risk control measure, and the following Equation 13, which is the Net Cost of Averting a Fatality (NCAF) for measuring the degree of cost-effectiveness by expressing the risk control measure as a ratio of marginal cost considering economic benefits from the perspective of reducing risk to human life. Equation (12) Equation (13) (Here, △C is the lifetime cost of applying Risk Control Orders (RCO), △B is the lifetime economic benefit obtained as a result of applying Risk Control Orders (RCO), and △R is the reduction in risk in terms of casualty reduction resulting from the application of Risk Control Orders (RCO).)
  15. In Clause 14, the above cost-benefit analysis step is, A risk assessment method derived from the following equation (14), which is the Net Present Value (NPV), to calculate the sum of the annual costs incurred by applying the above risk control method (RCO) from the time of initial installation to the end of the ship's lifespan by converting the flow of costs into present value. Equation (14) (here, is the cost or benefit at time t (flow period of costs) resulting from the application of the Risk Control Plan, A is the initial cost required to apply the Risk Control Plan (RCO), r is the depreciation rate, and T is the lifespan of the vessel)

Description

A Developed Risk Assessment Methodology based on Formal Safety Assessment for Marine Engine System The present invention relates to an enhanced risk assessment method based on an official safety assessment for marine engines, and more specifically, to an enhanced risk assessment method based on an official safety assessment for marine engines that can objectively and rationally assess risk by supplementing the uncertainty of the qualitative risk assessment based on the qualitative risk assessment of the official safety assessment. For the design and development of new vessels, it is necessary to evaluate the safety of ship components, such as marine engine systems, and demonstrate improved safety compared to existing ship components. To this end, the International Maritime Organization (IMO) conducts Formal Safety Assessments (FSA). A Formal Safety Assessment (FSA) is a structured and systematic methodology aimed at improving maritime safety, including the protection of human life, the marine environment, and property, based on risk analysis and cost-benefit assessment. It serves as a means to facilitate the modification and development of regulations by evaluating new regulations, comparing existing regulations with new (proposed) regulations, and building consensus among various stakeholders. Conventional Korean Registered Patent No. 10-1245385 disclosed the creation of a ship safety assessment model and a ship safety assessment method using the same, which supports the performance of rapid and iterative safety assessments considering design characteristics performed within limited time and budget constraints, and enhances the understanding of stakeholders regarding the results of the safety assessment. However, since the primary objective of the conventional ship safety assessment method based on the Formal Safety Assessment (FSA) is to prevent ship accidents in advance, a vast amount of time and manpower is required in the stages of identifying risk factors and establishing risk control measures. Therefore, in order to enhance the efficiency of time required for risk assessment in the shipping industry and to complement the uncertainties of qualitative risk assessments such as FMEA and HAZOP, it is necessary to conduct more objective and rational risk assessments. FIG. 1 is a flowchart of an enhanced risk assessment method based on formal safety assessment for a marine engine according to the present invention. FIG. 2 is an example diagram of FMEA, which is a top-down approach system for the risk impact assessment table preparation step according to the present invention. FIG. 3 is an example diagram of a risk matrix of the risk ranking derivation step according to the present invention. FIG. 4 is a detailed flowchart of the ranking step of the enhanced risk assessment method based on official safety assessment for a marine engine according to the present invention. FIG. 5 is a flowchart of the preparation steps for the safety assessment work of the enhanced risk assessment method based on formal safety assessment for a marine engine according to the present invention. FIG. 6 is a detailed flowchart of the formal safety evaluation step of the enhanced risk assessment method based on formal safety evaluation for a marine engine according to the present invention. The present invention will be described in more detail below through specific examples or embodiments, including the attached drawings. However, the following specific examples or embodiments are merely references for the detailed description of the present invention and the present invention is not limited thereto and may be implemented in various forms. Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as generally understood by one of the art to which the present invention pertains. Terms used for illustrative purposes in the present invention are merely intended to effectively describe specific embodiments and are not intended to limit the present invention. Additionally, the singular form used in the specification and the appended claims may be intended to include the plural form unless specifically indicated otherwise in the context. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. An enhanced risk assessment method based on an official safety assessment for a marine engine according to the present invention comprises: a risk impact assessment table creation step for a marine engine system that structures the system of a marine engine by hierarchizing it into mission, function, system, and subsystem, and creates a risk impact assessment table for the marine engine system that is specified by items of failure signals, causes of failure, and opinions regarding causes of failure for said mission, function, system, and subsystem; and a ranking