The issues raised so far in the development of safety-critical systems have centered on how effectively the safety requirements are met in systems design. The systems are becoming more complex due to the increasing demand on the functionality and performance. As such, the integration of both the systems design and systems safety processes becomes more important and at the same time quite difficult to carry out. In this paper, an approach to solving the problem is presented, which is based on an integrated data model. To do so, the data generated from the inputs and outputs of the systems design and systems safety processes are analyzed first. The results of analysis are used to extract common attributes among the data, thereby making it possible to define classes. The classes then become the cores of the interface data model through which the interaction between the two processes under study can be modeled and interpreted. The approach taken has also been applied in a design case to demonstrate its value. It is expected that the results of the study could play a role of the stepping stone in extending to the architecture development of the integrated process.

On the Integration of Systems Design and Systems Safety Processes from an Integrated Data Model Viewpoint

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.

A Study on the Integration of Systems Engineering Process and Systems Safety Process in the Conceptual Design Stage to Improve Systems Safety

The present study aims to propose a method of carrying out the functional safety analysis to ensure the safety of the manufacturing process for weapon systems. The purpose of using weapon systems is to harm human life and destroy the property of hostile countries. Naturally, a weapon system involves explosives during its development and operation. As such, manufacturing processes for weapon systems have potential hazards of accidents that can cause fatal damages to humans or property. Some erroneous activities in the manufacturing process can produce dangerous results. For this reason, the safety of manufacturing processes in the defense industry domain is more crucial than other general manufacturing domain. To deal with such a safety issue, in this research, we propose a model-based approach to ensuring the safety of the manufacturing process for the defense industry. The proposal is primarily based on the concept of functional safety and includes the three steps: determination of safety integrity levels; selection of appropriate safety analysis methods; and execution of the analysis methods using SysML models. Using the results obtained in the study, one can identify the risk factors in a complex manufacturing environment in advance to take preventive actions against the potential loss that may arise.

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Model-Based Functional Safety Analysis of Manufacturing Processes for Weapon Systems

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.”

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Model-Based Architecture Design of the Range Safety Process for Live Fire Test with Enhanced Safety

It appears that the rapid advance in technology has allowed to broaden the variety of rail systems technology, thereby fostering new business opportunity in rail industry. The direction of rail systems operations is mainly two fold. In one direction, long distance operations between mega cities are pursued with help of high speed trains under development. In the other case, relatively short distance operations for covering intra-city or suburban area are becoming popular. A good example of the latter case is light rail transit (LRT) systems. Due to the short distance operation, it is thus expected that both the development and operation cost for LRT systems be reduced to some extent. The cost reduction desired in there can be gained by scaling down the sizes of both the trains and stations as compared to those of normal rail systems. However, it is not well known how the LRT stations can be scaled down. The objective of this paper is to study on how to slim down the stations (particularly, the functions room) of LRT systems. To achieve the objective, an approach is studied based on a modified method of design structure matrix (DSM). Specifically, using the enhanced DSM method, an integrated architecture is developed for the functions room, in which equipments are housed to perform the functions of electricity, signaling, and communication for LRT stations. The use of the result indicates that the desired reduction can be obtained with the approach taken in the paper.

On Slimming down the Functions Room of Light Rail Transit Stations by Utilizing an Enhanced DSM Method

Today`s war fields can be characterized by net-centric wars where a variety of independent weapon systems are operated in connection with each other via networks. As such, weapon systems become dramatically advanced in terms of complexity, functionality, precision and so on. It is then obvious that the defense R&D of those requires systematic and efficient development tools enabling the effective management of the complexity, budget/cost, development time, and risk all together. One viable approach is known to be the development methods based on systems engineering, which is already proved to successful in U.S. In this paper, a systems engineering approach is studied to be used in the conceptual design of advanced weapon systems. The approach is utilizing some graphical models in the design phase. As a target system, an unmanned aerial vehicle system is considered and the standard SysML is also used as a modeling language to create models. The generated models have several known merits such as ease of understanding and communication. The interrelationships between the models and the design artifacts are identified, which should be useful in the generation of some design documents that are required in the defense R&D. The result reported here could be utilized in the further study that can eventually lead to a full-scale model-based systems engineering method.

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On the Use of SysML Models in the Conceptual Design of Unmanned Aerial Vehicles

Recent technological advances in the domestic railway industry have turned out to deliver a profound impact on the forefront of other industries as well. Furthermore, the introduction of the high-speed railway systems has made it possible to travel around our country in a day, thereby changing our life styles a lot. However, it has been well recognized that many factors can cause unanticipated accidents during the operation. One of the causes is known to be the human errors made by the train operators in locomotive cabs. The problem is getting more serious as the trains run at high speed. As such, the objective of this paper is on how to improve the work environment of the locomotive cabs. Our approach is based on the systems engineering methodology. Specifically, we first identify the context and scope of the problem to be solved. We then continue our effort in deriving the requirements set to accomplish the improvement. These results are utilized in constructing a computer-aided management system for test and evaluation intended for the improvement. The approach taken and the results obtained in this paper is expected to make a contribution on the route to keeping our nation`s technologies on the competitive edges in the high-speed railway systems industry.

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On the Development of an Information System for Ergonomic Test and Evaluation of Locomotive Cabs

Today, a lot of research on autonomous driving technology is being conducted, and various vehicles with autonomous driving functions, such as ACC (adaptive cruise control) are being released. The autonomous vehicle recognizes obstacles ahead by the fusion of data from various sensors, such as lidar and radar sensors, including camera sensors. As the number of vehicles equipped with such autonomous driving functions increases, securing safety and reliability is a big issue. Recently, Mobileye proposed the RSS (responsibility-sensitive safety) model, which is a white box mathematical model, to secure the safety of autonomous vehicles and clarify responsibility in the case of an accident. In this paper, a method of applying the RSS model to a variable focus function camera that can cover the recognition range of a lidar sensor and a radar sensor with a single camera sensor is considered. The variables of the RSS model suitable for the variable focus function camera were defined, the variable values were determined, and the safe distances for each velocity were derived by applying the determined variable values. In addition, as a result of considering the time required to obtain the data, and the time required to change the focal length of the camera, it was confirmed that the response time obtained using the derived safe distance was a valid result.

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Young-Min Kim

Papers

On the Use of SysML Models in the Conceptual Design of Unmanned Aerial Vehicles

On the Integration of Systems Design and Systems Safety Processes from an Integrated Data Model Viewpoint

On the Development of an Information System for Ergonomic Test and Evaluation of Locomotive Cabs

A Study on the Integration of Systems Engineering Process and Systems Safety Process in the Conceptual Design Stage to Improve Systems Safety

On the Development of Autonomous Vehicle Safety Distance by an RSS Model Based on a Variable Focus Function Camera