• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.1-10
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• 2012

Recently, we have witnessed the definitely negative impacts of large-scale accidents happened in such areas as atomic power plants and high-speed train systems, which result in increased fear for the potential danger. The problems appear to arise due to the deficiency in the design of large-scale complex systems. One of the causes can be attributed to the design process that does not fully reflect the safety requirements in the early stage of the system development because of the substantially increased complexity. In this paper, to enhance the systems safety an integrated process is studied, which considers simultaneously both the system design process and system safety process from the beginning of the system development. In the conceptual system design phase an integrated process model is constructed by analyzing the activities of both the system design and safety processes. As a case study example, an inner city train system is described with the application of the developed process. The computer simulation of the example case is followed by the result discussed. The results obtained in the paper are expected to be the basis for the future study where a detailed process and its associated activities can be developed.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.51-60
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• 2013

As the human demand or desire on brand new systems otherwise equipped with new functions grows drastically, so does the complexity of the systems. With this trend, the systems are becoming bigger in scale and at the same time the safety requirements are more stringent in the development. Typical systems examples in such a situation may include high-speed railway systems, aero and space systems, marine systems, etc. Failure of those systems can cause serious damages on both the human being and wealth with social infrastructure. As such, it is quite necessary to ensure that the safety requirements be satisfied in the system development. To achieve this need, there could be a lot of solutions to take. In this paper, regarding safety, a special attention is given to the verification phase process, which is one of the intermediate phases of whole systems development process. More specifically, the ultimate concern is placed on how to carry out the design verification while ensuring the safety requirements. To do so, some improvements in the verification phase were proposed first. Then, the outcomes were combined with the systems safety process by generating an integrated process model to reach the goal. As a case study, application to a railway system was discussed, where strict safety requirements are usually necessary. It would be expected that the potential likelihood of failure with rail systems could be reduced if the results obtained are used effectively with some enhancement from further study.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.51-60
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• 2013

With the recent changes in the environment of weapon systems acquisition, the systems development is becoming more susceptible to a variety of risks. To cope with this situation, US DoD has been emphasizing the importance of constantly applying the test and evaluation (T&E) process throughout the whole life cycle of the weapon systems. In particular, the safety requirements are called for attention while dealing with system risks. To this end, the present paper is aimed at studying the T&E process which incorporates the systems safety in weapon systems development. Analyzing and modeling the relevant processes has made it possible to achieve the objective. As a case study, the model results were applied to the development of unmanned aerial vehicles.

• Journal of Korean Society for Quality Management
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• v.41 no.4
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• pp.725-735
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• 2013

Purpose: The purpose of this study is to propose an Integrated Safety Evaluation Process (ISEP) that can enhances the safety aspect of the safety-critical system. This process utilizes the advantages of the iterative Systems Engineering process combined with the safety assessment process that is commonly and well defined in many standards and/or guidelines for railway, aerospace, and other safety-critical systems. Methods: The proposed process model is based on the predefined system lifecycle, in each phase of which the appropriate safety assessment activities and the safety data are identified. The interfaces between Systems Engineering process and the safety assessment process are identified before the two processes are integrated. For the integration, the elements at lower level of Systems Engineering process are combined with the relevant elements of safety assessment process. This combined process model is represented as Enhanced Functional Flow Block Diagram (EFFBD) by using CORE(R) that is commercial modelling tool. Results: The proposed model is applied to the lifecycle and management process of the United States aircraft system. The US aircraft systems engineering process are composed of twelve key elements, among which the requirements management, functional analysis, and Synthesis processes are considered for examplenary application of the proposed process. To synchronize the Systems Engineering process and the safety assessment process, the Systems Engineering milestones are utilized, where the US aircraft system has thirteen milestones. Taking into account of the nine steps in the maturity level, the integrated process models are proposed in some phases of lifecycle. The flows of processes are simulated using CORE(R), confirming the flows are timelined without any conflict between the Systems Engineering process and the safety assessment process. Conclusion: ISEP allows the timeline analysis for identifying activity and data flows. Also, the use of CORE(R) is shown to be effective in the management and change of process data, which helps for the ISEP to apply for the development of safety critical system. In this study, only the first few phases of lifecyle are considered, however, the implementation through operation phases can be revised by combining the elements of safety activities regarding those phases.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.1
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• pp.29-38
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• 2023

Independent Safety Assessment (ISA) is a third-party assessment that is to confirm that the system satisfies the safety requirements in the defined operational context. The process of this assessment often brings about many complex arguments that should be supported by evidence and justification. The communication between arguments and evidence is of the most importance in the context of safety case. This study illustrates how NOR-STA can be used for ISA process, showing the effective structure of safety compliance. The study outlines the steps to breaks down the top goal into many elements such as arguments, sub-goals, justification, context and assumptions. It concludes that the evidence-based safety conformance process utilizing NOR-STA provides a more effective and systematic representation of the independent safety assessment process in conformance cases.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.19-26
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• 2009

It is becoming more and more important to develop safety-critical systems with special attention. Examples of the safety-critical systems include the mass transportation systems such as high speed trains, airplanes, ships and so forth. Safety critical issues can also exist in the development of atomic power plants that are attracting a great deal of attention recently as oil prices are sky-rocketing. Note that the safety-critical systems are in general large-scale and very complex for which case the effects of adopting the systems engineering (SE) approach has been quite phenomenal. Furthermore, safety-critical requirements should necessarily be realized in the design phase and be effectively maintained thereafter. In light of these comments, we have considered our approach to developing safety-critical systems to be based on the method combining the systems engineering and safety management processes. To do so, we have developed a design environment by constructing a whole life cycle model in two steps. In the first step, the integrated process model was developed by integrating the SE (ISO/IEC 15283) and systems safety (e.g., hazard analysis) activities and implemented in a computer-aided SE tool environment. The model was represented by three hierarchical levels: the life-cycle level, the process level, and the activity level. As a result, one can see from the model when and how the required SE and safety processes have to be carried out concurrently and iterately. Finally, the design environment was verified by the computer simulation.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.123-131
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• 2014

Modern weapon systems are getting more complex in terms of the functionality and also the conditions on the environment and range in which they are deployed and used. Therefore, many development programs can easily be exposed to a variety of risks, resulting in delayed schedules and cost overrun. As such, effective means are necessary to keep the defence budget at an affordable level while competitive edges on technological aspects are retained. As one way to meet those need, modeling and simulation (M&S) methods have widely been used, particularly in the test and evaluation (T&E) process for weapon systems development. The result of M&S-based systems development should be evaluated by the verification, validation & accreditation (VV&A) process to assure keeping reliability at a desired level. On the other hand, due to the explosiveness, the weapons systems development naturally requires to consider safety issues in both the T&E and operational periods. The purpose of this paper is to improve the VV&A process by reflecting the safety requirements therein. To do so, the VV&A process has been analyzed and graphically modeled first and then safety elements have been incorporated effectively. The use of the improved process in the war ships development has also been discussed. Based on the process proposed and the consequent database constructed, the target system can be expected to benefit from reducing development risks while assuring systems safety.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.89-96
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• 2015

The weapon systems development has some distinct characteristics in that a big size of government budget (derived from national tax) has been expended frequently and the completion of the development projects seems to take long. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks. As such, proper management of project risk has been one of crucial subjects in the weapon systems development. Although a variety of methods can be considered, an approach based on the test and evaluation (T&E) process has been selected in this paper in order to appropriately handle those potential risks. In the study of the underlying T&E process, the safety consideration (for instance, explosiveness) of weapon systems is also included. To achieve the objective of the paper, a step-by-step procedure is first presented in the analysis of the T&E process. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored based on a design structure matrix method. The case study of a tank development is also discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.129-138
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• 2016

The train-centric control systems development has some distinct points in that a big size of government budget is in general expended in there and the development duration seems to be long. In addition, the changes are ever made continuously in the capability and operational requirements for Trains. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks [7]. As such, proper management of project risk has been one of crucial subjects in the train systems development. All these notes combined together make it the significance of the safety management process be raised further up in the train-centric control systems development. As such, the underlying safety management process should be capable of appropriately handling the potential risks that can be created due to the unexpected changes and the long-term development period. The process should also be complemented for the safety consideration of train-centric control systems, for instance, stop. To study these aspect is the objective of the paper. To do so, a step-by-step approach to analyzing the safety management process is first presented. Then, to enhance the process some necessary and useful activities are added in terms of risk and safety management. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored using a design structure matrix method. The resultant process is applied in a train-centric control development as a case study.

• Journal of the Korea Safety Management & Science
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• v.16 no.2
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• pp.43-52
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• 2014

In weapon systems development, live fire tests have been frequently adopted to evaluate the performance of the systems under development. Therefore, it is necessary to ensure safety in the test ranges where the live fire tests can cause serious hazards. During the tests, a special care must be taken to protect the test and evaluation (T&E) personnel and also test assets from potential danger and hazards. Thus, the development and management of the range safety process is quite important in the tests of guided missiles and artillery considering the explosive power of the destruction. Note also that with a newly evolving era of weapon systems such as laser, EMP and non-lethal weapons, the test procedure for such systems is very complex. Therefore, keeping the safety level in the test ranges is getting more difficult due to the increased unpredictability for unknown hazards. The objective of this paper is to study on how to enhance the safety in the test ranges. To do so, an approach is proposed based on model-based systems engineering (MBSE). Specifically, a functional architecture is derived utilizing the MBSE method for the design of the range safety process under the condition that the derived architecture must satisfy both the complex test situation and the safety requirements. The architecture developed in the paper has also been investigated by simulation using a computer-aided systems engineering tool. The systematic application of this study in weapon live tests is expected to reduce unexpected hazards and test design time. Our approach is intended to be a trial to get closer to the recent theme in T&E community, "Testing at the speed of stakeholder's need and rapid requirement for rapid acquisition."