CBTC 시스템 개발을 위한 시스템엔지니어링과 안전성 분석의 통합

박중용,박영원 한국철도학회 2003 한국철도학회논문집 Vol.6 No.1

This article proposes an integrated systems engineering and safety analysis model for safety-critical systems development. A methodology in system design for safety is considered during the early phase of the development life cycle of systems engineering process. The evolution of the design automation technology has enabled engineers to perform the model-based systems engineering. A Computer-Aided Systems Engineering(CASE) tool, CORE, is utilized to integrate the systems engineering model with a system safety analysis model. The results of the functional analysis phase can drive the analysis of the system safety. An example of Communications-Based Train Control(CBTC) system for an Automated Guided Transit(AGT) system demonstrated an application of the integrated model.

함정 전투체계 개발을 위한 모델기반 시스템 엔지니어링 프로세스 연구

조명섭,송하석,윤태훈,오성균,박영원,Cho, Myeong Seob,Song, Ha Seok,Yoon, Tae Hun,Oh, Sung Gyun,Park, Young Won 한국시스템엔지니어링학회 2012 시스템엔지니어링학술지 Vol.8 No.1

The conventional systems engineering has been performed mainly based on documentation artifacts. Although the Document-Based Systems Engineering has played a very important role in developing and deploying systems, it is difficult for systems engineers to build, to clarify, and to reuse the operational, functional and physical views of the System of Interest (SOI) efficiently. An information-age approach to this problem is the Model-Based Systems Engineering which has been emerging as a very productive solution for stakeholders to define, and understand the desired systems easily, to communicate and collaborate efficiently among each other, and also to verify and validate the systems solutions effectively. This paper proposes a set of MBSE process, methods, and models for use during the systems analysis and design phase of the naval combat system development. An example application of the proposed approach was exercised and a set of artifacts was generated for an export combat system project to demonstrate its effectiveness.

안전중시 시스템의 모델기반 설계에서 메타모델을 활용한 기능 고장의 탐지 및 안전 요구사항 검증

김영현(Young-Hyun Kim),이재천(Jae-Chon Lee) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.9

사용자의 요구사항 증대와 기술의 발전으로 인해 현대 시스템은 계속해서 복잡해지고 있어 시스템 설계 오류 및 고장 등으로 인한 시스템 운용 중의 사고도 빈번해지고 있다. 특히 사고로 인한 인적 및 물적 피해가 심각할 수 있는 시스템을 안전중시 시스템이라고 부른다. 이러한 시스템에 대해서는 안전성을 확보하기 위한 특별한 노력이 필요한데 이에 부응하여 본 논문에서는 개발 초기 단계부터 안전성을 반영하면서 시스템 설계를 수행할 수 있는 방법을 연구하였다. 특히 안전 메타모델을 활용해서 기능의 고장 탐지를 수행할 수 있는 시스템 설계 방법을 제시하였다. 구체적으로 국제 안전 표준들을 참고하여 안전 데이터를 추출하고, 시스템 모델링 표준 언어인 SysML을 이용하여 안전 데이터 메타모델을 생성한 후, 시스템 설계에서 안전 데이터 메타모델을 효과적으로 활용하는 모델 기반 안전 시스템 설계 방법을 제시하였고, 이를 기반으로 안전요구사항 생성 및 시뮬레이션 방법에 관하여 논의하였다. 마지막으로 사례연구로서 자동차 시스템 설계에서 SysML 기반 모델링 및 시뮬레이션을 통해 기능 고장의 탐지나 안전 요구사항의 검증이 가능한 것을 보여 주었다. 본 연구에서 안전 데이터에 대한 메타모델의 활용을 통해 안전 데이터 및 정보의 구성 및 관리를 효율적으로 수행할 수 있는 것과, 메타모델 기반 시스템 설계와 시뮬레이션을 활용하여 설계 오류를 줄임으로써 요구사항에 맞는 시스템 설계를 할 수 있음을 제시하였다. Modern systems have become more and more complex due to the ever-increasing user requirements and rapid advance of technology. As such, the frequency of accidents due to system design errors or failure has been increasing. When the damage incurred by accidents to human beings or property is serious, the underlying systems are referred to as safety-critical systems. The development of such systems requires special efforts to ensure the safety of the human beings operating them. To cope with such a requirement, in this paper an approach is employed in which we consider safety starting from the conceptual design phase of the systems. Specifically, a systems design method that can detect functional failure is proposed by utilizing meta-models and M&S methods. To accomplish this, the safety design data from international safety standards are first extracted and also a meta-model is generated using SysML (systems modeling language). Then, a SysML-based system design method is proposed based on the use of the developed meta-model. We also discuss how the safety requirements can be created and verified using a simulation method. Finally, through a case study in automotive design, it is demonstrated that the detection of a functional failure and the verification of a safety requirement can be accomplished using the SysML-based M&S method. This study indicates that the use of meta-models can be useful for collecting and managing safety data and that the meta-model based M&S method can make it possible to satisfy the system requirements by reducing the design errors.

Application of Sequence Diagrams to the Reverse Engineering Process of the ESf-ccs

Hasan, Md. Mehedi,Elakrat, Mohamed,Mayaka, Joyce,Jung, Jae Cheon The Korean Society of Systems Engineering 2019 시스템엔지니어링학술지 Vol.15 No.1

Reverse engineering involves examining a system or component so as to comprehend its structure, functionality, and operation. Creation of a system model in reverse engineering can serve several purposes: test generation, change impact analysis, and the creation of a new or modified system. When attempting to reverse engineering a system, often the most readily accessible information is the system description, which does not readily lend itself to use in Model Based System Engineering (MBSE). Therefore, it is necessary to be able to transform this description into a diagram, which clearly depicts the behavior of the system as well as the interaction between components. This study demonstrates how sequence diagrams can be extracted from the systems description. Using MBSE software, the sequence diagrams for the Engineered Safety Features Component Control System (ESF-CCS) of the Nuclear Power Plant are created. Sequence diagrams are chosen because they are a means of representing the systems behavior and the interaction between components. In addition, from these diagrams, the system's functional requirements can be elicited. These diagrams then serve as the baseline of the reverse engineering process and multiple system views are subsequently be created from them, thus speeding up the development process. In addition, the use of MBSE ensures that any additional information obtained from auxiliary sources can then be input into the system model, ensuring data consistency.

A Proposal of Quality Assessment for System Model

Onozuka, Yuki,Ioki, Makoto,Shirasaka, Seiko The Korean Society of Systems Engineering 2016 시스템엔지니어링학술지 Vol.12 No.2

Recently, the increased complexity of systems has made systems engineering necessary. It is very useful for system designers to understand the whole context of the concerned system based on systems engineering. A system model can be used to describe the outcome of a system design. A system model describes the system from the viewpoint of the stakeholder's needs using the mutually exclusive and collectively exhaustive principle. A system model can be used to smoothly design a large and complicated system based on the systems engineering development process. Many companies and countries are attempting to apply model-based systems engineering, and the significance of the system model quality is increasing as system models are referenced during system development. In this paper, we propose a quality assessment method for ontology which is one of system models by focusing on the system development process. First, in this process, a system developer should explicitly show the relationship between viewpoints. Then, the system developer should select dependent rather than independent viewpoints. With dependent viewpoints, each viewpoint used to describe the system has some logical relationship. The set of viewpoints makes it possible to show, not only tangible and physical system parts, but also conceptual system parts. In this paper, we develop an ontological system model of a Japanese weather observation system. By comparing some ontological system models, we verify the effectiveness of explicitly describing the relationships between viewpoints and select dependent viewpoints.

Plant Equipment Modeling with Model Based Systems Engineering Approach

Shelly Salim,Joon-Young Kim(김준영),Taekyong Lee(이태경),Jae-Min Cha(차재민) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

Engineers use various techniques and tools in designing plant equipment. The resulting equipment designs might have different parameters and maturity levels. These models need to be integrated and verified against the process requirements. Also, equipment design has to be done rapidly to assist procurement and to enable timely construction. We propose to assist the equipment design of plant by creating models based on Model Based System Engineering (MBSE) approach. In MBSE, design data are managed as models, not as documents. Specifically, we defined the equipment design processes, requirements models, parametric models, and other supporting models that are represented as executable diagrams. We considered design activity where the equipment has been decided to be purchased from vendors rather than to be developed by the engineers. We also included an example of compressor design model with its parameter simulation and selection from catalogs. We discover that MBSE has a constraint in equipment designing, namely, it still requires domain-specific tools. This study is part of our effort to develop plant design methodology based on MBSE.

Development of Simplified DNBR Calculation Algorithm using Model-Based Systems Engineering Methodology

Awad, Ibrahim Fathy,Jung, Jae Cheon The Korean Society of Systems Engineering 2018 시스템엔지니어링학술지 Vol.14 No.2

System Complexity one of the most common cause failure of the projects, it leads to a lack of understanding about the functions of the system. Hence, the model is developed for communication and furthermore modeling help analysis, design, and understanding of the system. On the other hand, the text-based specification is useful and easy to develop but is difficult to visualize the physical composition, structure, and behaviour or data exchange of the system. Therefore, it is necessary to transform system description into a diagram which clearly depicts the behaviour of the system as well as the interaction between components. According to the International Atomic Energy Agency (IAEA) Safety Glossary, The safety system is a system important to safety, provided to ensure the safe shutdown of the reactor or the residual heat removal from the reactor core, or to limit the consequences of anticipated operational occurrences and design basis accidents. Core Protection Calculator System (CPCS) in Advanced Power Reactor 1400 (APR 1400) Nuclear Power Plant is a safety critical system. CPCS was developed using systems engineering method focusing on Departure from Nuclear Boiling Ratio (DNBR) calculation. Due to the complexity of the system, many diagrams are needed to minimize the risk of ambiguities and lack of understanding. Using Model-Based Systems Engineering (MBSE) software for modeling the DNBR algorithm were used. These diagrams then serve as the baseline of the reverse engineering process and speeding up the development process. In addition, the use of MBSE ensures that any additional information obtained from auxiliary sources can then be input into the system model, ensuring data consistency.

차상중심 열차제어시스템 개발에서 모델기반 접근을 통한 안전성 향상에 관한 연구

최명성(Myung-Sung Choi),김주욱(Joo-Uk Kim),한석윤(Seok-Youn Han),오세찬(Se-Chan Oh),심상현(Sang-Hyun Sim),이재천(Jae-Chon Lee) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.7

최근 철도 열차제어시스템은 최첨단 기술로 인한 무선통신기반 개발의 수요와 이에 따른 환경의 다변화, 설계 정보의 복잡성, 시스템 설계에 대한 추적성 등 여러 요인으로 인해 모델기반 설계와 안전에 대한 쟁점도 증가하고 있다. 이에 따라 기존의 열차제어시스템에서 다루는 지상 설비 설계에 대한 모델기반 설계와 단계별 안전 활동 강화의 필요성 역시 강조되고 있다. 이를 해결하기 위해서 본 논문에서는 먼저 열차제어시스템에 대한 효과적인 개발을 위하여 모델기반 설계를 수행하였 고 이는 SysML(System Modeling Language)을 활용하여 표현하였다. 열차제어시스템의 안전성 향상을 위하여 설계 모델을 활용할 수 있는 시험 시나리오를 생성하였다. 생성한 시험 시나리오에 모델기반 설계를 수행한 차상중심 열차제어시스템을 적용하여 사례 연구를 수행하였고 이에 대한 결과를 분석하여 본 연구의 활용 가능성을 입증하였다. 본 연구의 결과를 토대 로 안전성 향상 접근에 대한 시험 활동 재정립을 통해 개선함으로써 향후 모델을 기반 설계로 수행된 열차제어시스템 개발 시 개념설계에서 발생할 수 있는 비용 및 시간을 절감 시킬 수 있을 것으로 기대된다. The train control system is a facility to ensure model-based design and safe train operation, and its safety is the most important factor for system introduction, complexity of the design information and traceability etc. Therefore, the model-based design and safety activities regarding the way-side equipment of a train control system is also highlighted. To solve this problem, In this paper, model-based design was carried out first to develop an effective train control system, which is represented by SysML(System Modeling Language). The test scenarios that can take advantage of the design model were created to improve the train safety control system. Case studies of a model-based design of a train-centric train control system were applied to the test scenarios; the results demonstrated its usability. The improved activity over the test highlighted the safety improvement approach, and it is expected to reduce the cost and time in the conceptual design of a future development model-based train control system.

A Novel Approach for Deriving Test Scenarios and Test Cases from Events

Singh, Sandeep K.,Sabharwal, Sangeeta,Gupta, J.P. Korea Information Processing Society 2012 Journal of information processing systems Vol.8 No.2

Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test ma Safety critic Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test manually. In order to cut down on costs, save time, and increase reliability, the model based testing approach is the best solution. Such an approach does not require applications or codes prior to generating test cases, so it leads to the early detection of faults, which helps in reducing the development time. Several model-based testing approaches have used different UML models but very few works have been reported to show the generation of test cases that use events. Test cases that use events are an apt choice for these types of systems. However, these works have considered events that happen at a user interface level in a system while other events that happen in a system are not considered. Such works have limited applications in testing the GUI of a system. In this paper, a novel model-based testing approach is presented using business events, state events, and control events that have been captured directly from requirement specifications. The proposed approach documents events in event templates and then builds an event-flow model and a fault model for a system. Test coverage criterion and an algorithm are designed using these models to generate event sequence based test scenarios and test cases. Unlike other event based approaches, our approach is able to detect the proposed faults in a system. A prototype tool is developed to automate and evaluate the applicability of the entire process. Results have shown that the proposed approach and supportive tool is able to successfully derive test scenarios and test cases from the requirement specifications of safety critical systems, real time systems, and event based systems.

SysML 기반 M&S 기법을 통한 시스템 고장 모델의 검증

조정호(Jeong Ho Jo),이재천(Jae-Chon Lee) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.5

오늘날의 철도시스템을 비롯한 안전중시시스템은 그 복잡성과 전장구성품의 비중이 증가함에 따라, 시스템의 안전성 확보에 대한 필요성도 함께 증가하고 있다. 이를 반영하여 안전중시시스템에 대한 다양한 산업별 안전표준에서는 개념설계 단계에서부터 체계적인 위험원 분석을 수행하여 설계에 반영할 것을 요구하고 있다. 본 논문에서는 철도시스템의 개념설계 단계에서 수행되는 위험원 분석의 결과를 검증하기 위해서 SysML을 활용하여 시스템 고장 모델을 생성하고, 시뮬레이션을 통하여 검증하는 방법을 연구하였다. 구체적으로 먼저 대상시스템의 기능/물리 아키텍처를 SysML 기반으로 모델링하였다. 그리고 나서 시스템 모델에 대한 위험원 분석을 모델 기반으로 수행할 수 있도록 위험원 분석기법에서 공통적으로 다루는 고장 유형, 고장의 원인과 영향 등의 요소를 식별하여 시스템 모델에 추가하였다. 그 후 모델 기반 위험원 분석을 수행하고, 결과를 토대로 고장 모델을 정의하였다. 마지막으로 고장 모델이 반영된 시스템 모델을 시뮬레이션 함으로써 모델 기반 위험원 분석에 대한 검증을 수행하였다. 검증된 위험원 분석의 결과를 향후 효과적으로 안전 설계에 활용할 수 있다. There has been noticeable demand on safety assurance for the safety-critical systems such as rail systems as the underlying systems are getting more complex and using electronic/electrical components more frequently. As such, the functional safety standard and its variations have been developed and used in a variety of industrial domains. The standards are urging that hazard analysis be performed and the result incorporated in the systems design from the conceptual design phase. The objective of this study is to present a model-based approach to hazard analysis. Specifically, a system model including functional and physical models are developed first based on SysML. Those models are then used to construct systems failure models. Finally, to verify the model-based hazard analysis, simulation of the models developed are carried out. The verified results of hazard analysis would be useful in the design of corresponding safety systems.