Showing papers on "System of systems engineering published in 1989"

Multidisciplinary Optimization for Engineering Systems: Achievements and Potential

Abstract: The currently common sequential design process for engineering systems is likely to lead to suboptimal designs. Recently developed decomposition methods offer an alternative for coming closer to optimum by breaking the large task of system optimization into smaller, concurrently executed and, yet, coupled tasks, identified with engineering disciplines or subsystems. The hierarchic and non-hierarchic decompositions are discussed and illustrated by examples. In conclusion, an organization of a design process centered on the non-hierarchic decomposition is proposed.

Concurrent engineering: practices and prospects

Abstract: Concurrent engineering, a more systematic approach to creating high quality products at lower in significantly less time, has recently been promoted in the automotive, computer and electronics, and aerospace industries as a response to competitive pressures. It also attracted the attention of the Department of Defense and in 1988, the Institute for Defense Analyses (IDA) was asked to investigate concurrent engineering. The authors describe the investigation, present highlights of the evidence, and set forth the principal findings and recommendations. They include a sample of reported benefits, an outline of the methods and technologies of concurrent engineering, and a conceptual framework to describe the continuing research needed in this area. >

Introduction to Engineering

Abstract: History of Engineering Definition of Engineering Engineering Communications Engineering Calculations The Engineer as a Professional Learning and Creative Thought The Engineering Approach to Problem Solving Engineering Communications Engineering Calculations Engineering Mechanics Electronics Computers A Case Study--The Space Shuttle Challenger Accident Index.

Knowledge based systems in civil engineering

Abstract: (1989). Knowledge based systems in civil engineering. Civil Engineering Systems: Vol. 6, No. 1-2, pp. 3-4.

Computational Tools for Preliminary Engineering Design

Abstract: The primary objective of this work is to develop tools to aid the designer in developing designs; in making analyses; and in disqualifying unsatisfactory design configurations at the preliminary stages, where several different concepts (usually imprecisely defined) are simultaneously evaluated for feasibility and relative merit. Such tools are not “artificial intelligence”, in that the designer is providing both the creative idea generation, and making the decisions. Instead, the idea is to provide computational aids which present the information to the designer in such a way that the behavior of the input parameters with respect to the functional requirements may be readily understood.

Integrating expert systems into an operational environment

Abstract: The Communications Link Expert Assistance Resource Expert System is introduced. The experience gained in implementing this expert system is used to discuss solutions to the major problems encountered during the development of an expert system to be realized in an operational environment. Knowledge acquisition is discussed as well as user involvement, interfacing the system to the user, choosing a development environment, prototyping for success, and overcoming the transition.

Dynamic Systems-Engineering Process: The Application of Concurrent Engineering

Abstract: A system engineering methodology is described which enables users, particulary NASA and DOD, to accommodate changing needs; incorporate emerging technologies; identify, quantify, and manage system risks; manage evolving functional requirements; track the changing environment; and reduce system life-cycle costs. The approach is a concurrent, dynamic one which starts by constructing a performance model defining the required system functions and the interrelationships. A detailed probabilistic risk assessment of the system elements and their interrelationships is performed, and quantitative analysis of the reliability and maintainability of an engineering system allows its different technical and process failure modes to be identified and their probabilities to be computed. Decision makers can choose technical solutions that maximize an objective function and minimize the probability of failure under resource constraints.

Adaptations to the systems engineering management process for projects with incomplete requirements

Abstract: Ten adaptations to the traditional practice of systems engineering management are presented. Although they may require innovation, such adaptations are not without precedent since similar innovations have been implemented to assure that safety is achieved in manned space systems. The role of requirements in traditional systems engineering management projects is discussed. Systems that resist requirements definition and adaptations to management practices that reduce dependence on requirements are also discussed. >

CAST-Modelling Approaches in Engineering Design

Abstract: In this paper we have tried to point out what role systems theory can play in engineering design. One central aspect is the provision of CAST method banks, which are interactive method banks, for the enhancement of the skills of the designer. As a basic framework for the construction of the application system of such a method bank, we have introduced the concept of the STIX-machine STIX.M.

Systems and design as the basis of engineering knowledge

Abstract: Engineering knowledge has evolved into the traditional disciplines of electrical/electronic, mechanical/production and civil engineering, and it is strongly science-based. Engineering activity concerned with converting resources into forms suitable for use, suggests that engineering knowledge ought to be systems and design oriented. The objective of the paper is to describe the factors which are thought to facilitate development in this direction. In particular, the notion of a ‘system’ is defined in relation to the logic of explanation, and statements which describe the ‘physics’ of systems are formulated. The use of natural language, suitably processed as a modelling technique leading to the application of Prolog, is described. An engineering systems theory including control, which is based on the pertinent principles of physics, is explained. Present-day control theory is far removed from the framework of physics, engineering systems theory is intended to alleviate this remoteness; thus, removing fragmentation in this area of knowledge. A framework required for the development of systems component knowledge is outlined. Finally, a systems and product design method using natural language and Prolog is described. This method brings the design process closer to deductive thinking, thus facilitating its use and teaching. Accordingly, the consideration of synthesis, rather than the more usual analysis type problems, should become easier.

Systems in engineering

Abstract: The study of what systems are and how they work can help us understand much in the world of complex engineering enterprises

NASA-LaRc Flight-Critical Digital Systems Technology Workshop

Abstract: The outcome is documented of a Flight-Critical Digital Systems Technology Workshop held at NASA-Langley December 13 to 15 1988. The purpose of the workshop was to elicit the aerospace industry's view of the issues which must be addressed for the practical realization of flight-critical digital systems. The workshop was divided into three parts: an overview session; three half-day meetings of seven working groups addressing aeronautical and space requirements, system design for validation, failure modes, system modeling, reliable software, and flight test; and a half-day summary of the research issues presented by the working group chairmen. Issues that generated the most consensus across the workshop were: (1) the lack of effective design and validation methods with support tools to enable engineering of highly-integrated, flight-critical digital systems, and (2) the lack of high quality laboratory and field data on system failures especially due to electromagnetic environment (EME).

Method engineering: methods via methodology

Abstract: The computer industry has largely ignored lessons from professional and engineering disciplines. They recognise there are layers of skill, areas of specialisation and levels of quality constraint. Though there exist proprietary interests, these are founded on an established framework for comparison of products and services in their domains of interest. The computer industry spends too much time debating the merits of proprietary products and has no equivalent framework within which products can be compared. The author describes an approach to improving quality of service in the computer industry by developing such a framework which can avoid domination of the comparison of products by commercial smokescreens. >

The designer of the 90's: A live demonstration

Abstract: A survey of design tools to be used by the aircraft designer is given Structural reliability, maintainability, cost and predictability, and acoustics expert systems are discussed, as well as scheduling, drawing, engineering systems, sizing functions, and standard parts and materials data bases

Does civil engineering need system engineering

Abstract: System engineering has many definitions. In this paper it is defined as a total disciplined process of defining, creating, and operating large complex engineering systems. A brief history of the development and practice of system engineering is presented. Other definitions of system engineering are explored. On one extreme are system modeling and optimization activities and on the other are acquisition, requirements, and specification activities. Civil engineering, like other disciplines, has fragmented into many specialty groups. The common skills of integration, verification, and synthesis are often ignored by these specialty groups. System engineering skills are commonly focused on the definition and translation of needs and solutions at each phase and level of a system development. New computer technology permits the process of system engineering to be automated and performed in real time and at much lower costs. The question raised in this paper is whether the civil engineering profession currently p...

Multiple cooperating views: a new perspective for systems engineering

Abstract: Describes concepts and approaches for modifying classical system engineering to better handle complex human computer systems. A summary of classical system engineering is given, and its failure to cope with user-based systems issues is revealed. The need for early validation of operational concepts and user requirements is established as the single most important system engineering activity to reduce life-cycle costs substantially. A set of five system engineering perspectives is defined, and a strategy called multiple cooperating views is described for managing the process. A perspective, user engineering, is defined and related to the other perspectives. An example of multiple cooperating views for user and design engineering perspectives is given to demonstrate the process further. >

The inter-relationship between systems engineering and engineering design

Abstract: Systems engineering is the technology of the design, operation and management of large and complex systems. The methodologies of engineering product design are converging with systems methodology, and there is a need for the two to develop in close interaction. The authors individually provide overviews, from the points of view of systems, design and management.

GEMINI-government expert systems method initiative

Abstract: GEMINI is a national initiative to lay the foundations for a publicly available expert systems development methodology to complement and integrate with software engineering methods including SSADM. The paper outlines the rationale behind project GEMINI and reports on progress and plans. The objectives of the full GEMINI programme, aimed at establishing the method, are outlined in order to provide the context for Stage I, the method definition study, which is now complete. Some results of the study are given and an update on progress and outline of future plans is presented. >

Suggested criteria for evaluating systems engineering methodologies

Abstract: Systems engineering is the application of mathematical and scientific principles to practical ends in the life-cycle of a system. A methodology for systems engineering is a carefully developed, relatively complex procedure or process for applying these mathematical and scientific principles. There are many systems engineering methodologies (or possibly many versions of a few methodologies) currently in use in government and industry. These methodologies are usually designed to meet the needs of a particular organization. It has been observed, however, that many technical and non-technical problems arise when inadequate systems engineering methodologies are applied by organizations to their systems development projects. Various criteria for evaluating systems engineering methodologies are discussed. Such criteria are developed to assist methodology-users in identifying and selecting methodologies that best fit the needs of the organization.

Workstations for systems engineers

Abstract: System engineering currently accounts for more than 10% of the engineering effort on large complex system development efforts and this percentage has been increasing as more cost overruns and more system failures are experienced. As the complexity of many programs has increased, the costs of traditional system engineering practices have grown geometrically. The only way that the benefits of system engineering can be kept ahead of the cost of providing system engineering is to automate many of the tedious tasks that are performed. This paper examines the types of system engineering activities that can be automated with an engineering workstation and examines the arguments that are encountered when an organization considers the introduction of such workstations.

An integrated tool box for the electrical engineer

Abstract: The authors present concepts for the integration of software components such as CAD systems, document management systems and expert systems into a tool box for the electrical engineer and describe the architecture of such a system for computer-integrated engineering (CIE). The kernel of the tool box is an engineering database system based on an active DBMS for maintaining the logical integrity of engineering data. The schema of the engineering database consists of a predefined kernel schema of commonly used objects of electrical engineering and a user-definable part. A CIE modeling system is made available for the definition of user-specific data structures, relationships, and engineering rules. >

An automated engineering environment

Abstract: The author describes an integrated engineering environment developed to address the critical problem of fragmented and/or nonexistent engineering technical resources. Before the development of this Engineering Central Computing Facility (ECCF), resources that did exist were located in obscure locations primarily intended for a select audience. The ECCF makes this tools accessible to the entire engineering community and adds the necessary tools for day-to-day engineering tasks which would otherwise be preformed manually. The base's local area network provides the backbone for the system. Software capabilities have been provided in the mechanical, facilities design, electronic/electrical, and engineering documentation areas. The core computing consists of a cluster of minicomputers which provides generic-type services. Application software is hosted on the central host cluster, utilizing a library concept for package check-out and check-in. Secondary file service is provided at various locations throughout the base. This is primarily for user-specific requirements and may also be accessed from any remote location. >