System Design From Provably Correct Constructs

This book contains a refereed collection of thoroughly revised full papers based on the contributions accepted for presentation at the International Workshop on Studies of Software Design, held in conjunction with the 1993 International Conference on Software Engineering, ICSE'93, in Baltimore, Maryland, in May 1993. The emphasis of the 13 papers included is on methods for studying, analyzing, and comparing designs and design methods; the topical focus is primarily on the software architecture level of design and on techniques suitable for dealing with large software systems. The book is organized in sections on architectures, tools, and design methods and opens with a detailed introduction by the volume editor.

Contains papers presented at "Expert Systems 88", the eighth annual conference of the British Computer Society Specialist Group on Expert Systems, held in Brighton in December 1988. Covers many aspects of current work, in particular, theoretical topics, practical techniques and real applications of expert systems (a wide spectrum of commercial and industrial interest). The theme of the 1988 conference was "integrating with mainstream software development." No index. Annotation copyrighted by Book News, Inc., Portland, OR

1 INTRODUCTION These proceedings are the result of a conference on Automating Systems Development held at Leicester Polytechnic, England on 14 to 16 April 1987. The conference was attended by over 170 delegates from industry and academia and it represents a comprehensive review of the state of the art of the use of the computer based tools for the analysis, design and construction of Information Systems (IS). Two parallel streams ran throughout the conference. The academic, or research, papers were the fruit of British, European and Canadian research, with some of the papers reflecting UK Government funded Alvey or European ESPRIT research projects. Two important touchstones guided the selection of academic papers. Firstly, they should be primarily concerned with system, rather than program, development. Secondly, they should be easily accessible to delegates and readers. We felt that formal mathematical papers had plenty of other opportunities for airing and publication. The second stream was the applied programme; a set of formal presentations given by leading software vendors and consultancies. It is clear that many advances in systems development are actually applied, rather than re search led. Thus it was important for delegates to hear how leading edge companies view the State of the Art. This was supported by a small exhibi tion area where certain vendors demonstrated the software they had intro duced in the formal presentation.

Addressing general readers as well as software practitioners, "Software and Mind" discusses the fallacies of the mechanistic ideology and the degradation of minds caused by these fallacies. Mechanism holds that every aspect of the world can be represented as a simple hierarchical structure of entities. But, while useful in fields like mathematics and manufacturing, this idea is generally worthless, because most aspects of the world are too complex to be reduced to simple hierarchical structures. Our software-related affairs, in particular, cannot be represented in this fashion. And yet, all programming theories and development systems, and all software applications, attempt to reduce real-world problems to neat hierarchical structures of data, operations, and features. Using Karl Popper's famous principles of demarcation between science and pseudoscience, the book shows that the mechanistic ideology has turned most of our software-related activities into pseudoscientific pursuits. Using mechanism as warrant, the software elites are promoting invalid, even fraudulent, software notions. They force us to depend on generic, inferior systems, instead of allowing us to develop software skills and to create our own systems. Software mechanism emulates the methods of manufacturing, and thereby restricts us to high levels of abstraction and simple, isolated structures. The benefits of software, however, can be attained only if we start with low-level elements and learn to create complex, interacting structures. Software, the book argues, is a non-mechanistic phenomenon. So it is akin to language, not to physical objects. Like language, it permits us to mirror the world in our minds and to communicate with it. Moreover, we increasingly depend on software in everything we do, in the same way that we depend on language. Thus, being restricted to mechanistic software is like thinking and communicating while being restricted to some ready-made sentences supplied by an elite. Ultimately, by impoverishing software, our elites are achieving what the totalitarian elite described by George Orwell in "Nineteen Eighty-Four" achieves by impoverishing language: they are degrading our minds.

This volume contains the proceedings of the NATO Advanced Study Institute on "Picture Archiving and Communication Systems (PACS) in Medicine" held in Evian, France, October 14- 26, 1990. The program committee of the institute consisted of H.K. Huang (Director), Osman Ratib, Albert Bakker, and Gerd Witte. This institute brought together approximately 90 participants from 15 countries. These proceedings are the accumulation of eight years of research and development results in PACS by various dedicated groups throughout the world. The purpose of this institute was to review the most recent technology available for PACS and some clinical results. The readers should notice the remarkable advances in this field by comparing the contents in these proceedings with those in a previous institute on "Pictorial Information Systems in Medicine" held August 27 - September 7, 1984 in Braunlage/Harz, Federal Republic of Germany, and published as Vol. 19 in this series. The institute was organized according to four categories: PACS components and system integration, PACS and related research in various countries and manufacturing companies, clinical experience and research support, and participants' scientific communications. In PACS components, we included image acquisition, workstations, data storage and networking. In system integration, topics on interfaces between Hospital Information System (HIS), Radiology Information System (RIS) and PACS, clinical reports, the ACR/NEMA standard, databases, reliability, and system integration were discussed. This lecture series emphasized the technical detail and "how to" aspects.

Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth models. The next chapter deals with methods for predicting and estimating software reliability, with emphasis on their strengths and weaknesses. The reader is methodically introduced to formal inspection in software development; the effects of product design, program structure, development methods, and the environments of product testing and use on product reliability; and types of software metrics in relation to reliability. The remaining chapters explore the ways in which software engineers have sought to achieve software reliability through testing; problems and standards in software reliability data collection; and applications of time series models to software reliability analysis. This monograph will be of interest to software engineers and designers.

Computer systems play an important role in our society. Software drives those systems. Massive investments of time and resources are made in developing and implementing these systems. Maintenance is inevitable. It is hard and costly. Considerable resources are required to keep the systems active and dependable. We cannot maintain software unless maintainability characters are built into the products and processes. There is an urgent need to reinforce software development practices based on quality and reliability principles. Though maintenance is a mini development lifecycle, it has its own problems. Maintenance issues need corresponding tools and techniques to address them. Software professionals are key players in maintenance. While development is an art and science, maintenance is a craft. We need to develop maintenance personnel to master this craft. Technology impact is very high in systems world today. We can no longer conduct business in the way we did before. That calls for reengineering systems and software. Even reengineered software needs maintenance, soon after its implementation. We have to take business knowledge, procedures, and data into the newly reengineered world. Software maintenance people can play an important role in this migration process. Software technology is moving into global and distributed networking environments. Client/server systems and object-orientation are on their way. Massively parallel processing systems and networking resources are changing database services into corporate data warehouses. Software engineering environments, rapid application development tools are changing the way we used to develop and maintain software. Software maintenance is moving from code maintenance to design maintenance, even onto specification maintenance. Modifications today are made at specification level, regenating the software components, testing and integrating them with the system. Eventually software maintenance has to manage the evolution and evolutionary characteristics of software systems. Software professionals have to maintain not only the software, but the momentum of change in systems and software. In this study, we observe various issues, tools and techniques, and the emerging trends in software technology with particular reference to maintenance. We are not searching for specific solutions. We are identifying issues and finding ways to manage them, live with them, and control their negative impact.