Jae-Chon Lee

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

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.

On Software Reliability Engineering Process for Weapon Systems

As weapon systems are evolving into more advanced and complex ones, the role of the software is becoming heavily significant in their developments. Particularly in the war field of today as represented by the network centric warfare(NCW), the reliability of weapon systems is definitely crucial. In this context, it is inevitable to develop software reliably enough to make the weapon systems operate robustly in the combat field. The reliability engineering activities performed to develop software in the domestic area seem to be limited to the software reliability estimations for some projects. To ensure that the target reliability of software be maintained through the system`s development period, a more systematic approach to performing software reliability engineering activities are necessary from the beginning of the development period. In this paper, we consider the software reliability in terms of the development of a weapon system as a whole. Thus, from the systems engineering point of view, we analyze the models and methods that are related to software reliability and a variety of associated activities. As a result, a process is developed, which can be called the software reliability engineering process for weapon systems (SREP-WS), The developed SREP-WS can be used in the development of a weapon system to meet a target reliability throughout its life-cycle. Based on the SREP-WS, the software reliability could also be managed quantitatively.

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

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 the CMMI-Based Development of SE & PM Integration Process Architecture

Abstract The scale and required functionality of modern systems have increased and become more complicated. Tosuccessfully carry out the systems development projects, appropriate systems engineering (SE) and project management (PM) activities are required for the underlying process. In a system development organization, it is aneffort to secure the SE & PM capability by adopting the CMMI is an evaluation model of improvement and abilityof SE&PM process. To achieve the goal each organization establishes and uses its own organizational standard process, which satisfies the business characteristics. However, in practice, due to the lack of sufficient understanding on the interrelationship among different CMMI process areas, there still exist some difficulties with constructing organization processes. In systems development, the activities of SE are closely related with those of PM. Thus, theprocesses of SE and PM need to be fully integrated and explicitly linked to each other in order to complete the projects successfully. In this paper, we propose a SE&PM integration process architecture of organization that canbe utilized in the system development organization is referenced in the construction of CMMI-based organizationalprocess.

A Study on Constructing Common Database for Supporting Urban Rail Transit Project

A variety of Urban Rail Transit (URT) systems have been operating and they have different technology bases, causing a lot of difficulties in taking measures against trouble, training, upgrading, interoperability and so on. As such, a standardization project has been carried out to solve the problems by setting up the national standards for URT systems. A common database was built to provide the integrated engineering environment to the community of URT project. This paper discusses the design of the database and how it can be utilized in the successful promotion of the project. The products of the projects are stored into the database with traceability management to be referred to by other new URT projects for reusing and sharing the acquired knowledge through cross organizations.

Preparing Test and Evaluation Master Plan (TEMP) for the Korean CBTC System Development Project

A railroad signaling system is being developed in Korea, adopting the communication-based train control (CBTC) technology to control the train operation through radio communication. The project is intended to develop the interoperable and interchangeable subsystems as a trial, and will upgrade the existing system by replacing some of subsystems with new ones to be developed. The development activities have been concentrating on the subsystems development without performing sufficient design activities at the system level. This project shall require the integration and test at the system level. To do so, a top-level system specification is needed, which is not available in the current phase of the project. The purpose of this work is to study the problem when design specifications of the subsystems are given instead. A successful test of the integrated system consisting of developed subsystems requires a test and evaluation master plan (TEMP). The TEMP is usually generated during the concept design stage of the system development and addresses test and evaluation activities on a fully integrated basis to see whether the developed system meets the system specification. In this work, we describe how a TEMP can be generated based on the subsystems design specifications instead of the system specification, hi doing so, we have also utilized the system architecture as well as the system operation concept of the existing system.

Model-Based Integration of Test and Evaluation Process and System Safety Process for Development of Safety-Critical Weapon Systems.

In weapon system development, the necessity of adopting unestablished advanced technology is continuously increasing to address the competitive acquisition environment. Thus, an effective test and evaluation (TE this can potentially result in a variety of accidents. Therefore, an effective safety process is necessary. A systematic integration of T&E process and system safety process is required for the development of safety-critical weapon systems. To achieve this integration, a model-based approach is adopted in this study. Specifically, T&E and system safety processes are first studied with their constituent tasks. The identified tasks are then analyzed with a focus on the artifacts they produce. The result is used to obtain an initial model that represents the intended integrated process. Based on the process model, a design structure matrix (DSM) is constructed. Thereafter, the constructed DSM is sequenced and torn to obtain an enhanced process model, which effectively integrates the T&E and system safety processes. The resultant integrated process is evaluated through a case study, which revealed reduced complexity that can be transformed into reduced time and cost in the development of safety-critical weapon systems.

On Enhancing Safety of Train-Centric Train Control System using Model-Based Development

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.

Model Integration of Systems Design and Safety Analysis Processes for Systematic Design of Safety-Critical Systems

In safety-critical systems (SCS), failure may result in accidents with serious damage to human beings and property. As systems become more complex and automated, the goal of acquiring safety has attracted increasing attention lately in the defense industry, as well as the rail, automotive, and aerospace industries, among others. As such, the Department of Defense and international organizations have established appropriate standards and guidelines for systems safety and design. To this end, there has been research on the processes, methods, and associated tools for safety design. However, those results do not seem to sufficiently utilize system architectural information. The purpose of this paper is to provide a more systematic approach to SCS design. To better identify potential hazards, design information at each level of system hierarchy is exploited. Based on the results, an integrated process model was developed by combining the processes of system design and safety analysis. As a case study, the resultant integrated process model was applied to the safety design of an automobile system, which shows useful results for safety evaluation.

On a Maturity Model for the Institutionalization of Integrated SE&PM Process at Organization Level

Abstract To develop large-scale complex systems, many organizations have attempted to improve the processes specified in systems engineering (SE) and project management (PM) by adopting CMMI (Capability Maturity ModelIntegration). On the other hand, most domestic organizations that already acquired CMMI level 3 have focused on SE&PM practices while providing less investment in building up the environment for institutionalizing those processes. In such organizations, the process maturity without advancing to institutionalization can be neither enhancednor maintained. To resolve the problem, the following remedies can be suggested. A standard process should firstbe defined to meet the business mission of the organization and to carry out the process successfully, the people should be properly trained and the appropriate tools be provided. In this study, a maturity model to accomplish institutionalization was examined based on the aforementioned P-P-T (Process-People-Tool) concept. The model proposed would be useful in developing strategies and plans for process institutionalization when the organizationsare in the preparation stages for a CMMI certificate or have already acquired one.