This comprehensive guide, developed at IBM's International Technical Support Center in San Jose, CA, is ideal for managers and developers looking to apply object-oriented methods in large-scale information technology environments. Demonstrating the ups, downs, and trade-offs of object-oriented methodologies, the authors provide a wealth of information that will help managers make choices about the resources and technologies available for application development. The book discusses the impact of object technology on management decisions with examples from real, full-scale environments in which productivity has increased from the use of this technology.
Features of Object Technology: provides a solid explanation of the principles of object-oriented technology; describes and compares the methodologies in use in object-oriented development environments; analyzes the role of CASE tools in object-oriented development; presents the issues involved in building a user interface; includes a full chapter on the process of team building in object-oriented applications; details the use of a configuration management tool; and explains how "legacy code" can be reused in object-oriented environments.
"There is more to OOP then Syntax!" --Dr. Paul A. Luker
Since the publication of the first edition of Object Technology in Application Development only two years ago, the use of object technology by many of the world's largest corporations has grown immensely. The benefits of object-oriented methods have been proven in many different applications. With such widespread adoption of object technology, the need for information technology decision makers to clearly understand not only the benefits of object technology but also the pitfalls have increased dramatically. It starts with a situation many are already familiar with--the "software crisis."
Object Technology and the Software Crisis
As computing power and user access facilities have increased with technological change, the complexity of systems has also increased. More users are being served by computing systems and, aware of the available facilities, are becoming more demanding. User-friendly but complex graphical interfaces are becoming a standard requirement that is not easy to satisfy adequately with the current development tools and techniques. The maintenance backlog is also a severe burden that MIS departments must cope with: Most analysis, design, and documentation techniques used to implement today's applications do not accommodate changes.
This situation, known as "the software crisis," calls for a solution that could boost the productivity of MIS departments by an order of magnitude, at least. It is doubtful that the change of just one element--be it the tool, the skill, the programming language, or the paradigm--could produce such an increase in productivity. The attractiveness of such an instant solution was called by Fred Brooks "the lure of the silver bullet" BR087. But a sensible use of productive complementary tools and techniques, and a shift to a paradigm with proven advantages, can over time yield the desired results.
Object technology, which comprises object-oriented analysis (OOA), object-oriented design (OOD), and object-oriented programming (OOP), represents a paradigm that has proven its productivity in a small team programming environment over the last ten years. Now advances in OOA and OOD methodologies and in the languages and tools for OOP are providing an opportunity to achieve an equivalent increase in productivity in a corporate MIS environment. Today there is not single "silver bullet that can by itself kill the monster of missed schedules, blown budgets, and flawed products that can plague the application development projects," as Brooks so forcefully argued. However, the sound software principles of OOA and OOD, together with improvements in languages, tools, and training, and the establishment of a corporate reuse strategy, can increase productivity and reduce costs as well as improve the credibility of the projects and plans of MIS departments.
Changes to the Second Edition
The second edition reflects the rapidly changing environment of object technology. New technologies that enhance the abilities of object technology and new perspectives on its application have emerged. Perhaps the most important development is the advent of visual programming. Visual programming represents a major breakthrough in object-oriented applications development. Until recently, no methodology linked object technology and visual programming in a systematic and comprehensive fashion. The most significant change in the second edition of Object Technology in Application Development is the inclusion of a new chapter introducing the Visual Modeling Technique (VMT), a methodology developed at IBM that integrates visual programming into mainstream object-oriented development. In the object technology market, new tools such as IBM's VisualAge and newer, more robust versions of object languages like IBM Smalltalk have become available, strengthening the link between object technology and visual programming. The second edition includes a sample application using IBM Smalltalk. And as appropriate we have updated and changed coverage throughout the book to reflect additional developments in object technology.
Audience
This book was written for people who plan to develop applications using object technology. We also hope to assist management in making decisions on modifying the application development environment to accommodate object orientation. Our overriding purpose has been to help our readers understand the role of object technology in the development of computer-based applications. To that end we discuss the impact that object technology can have on the application development life cycle, the role of modeling and prototyping, methodologies involved, available languages and tools, ongoing standardization efforts, and management issues that are key to successful application construction and delivery.
The main audience of this book is, therefore, the professional world of software development. However, our academic experience indicates that the real-world approach, distinctive of this book, will make it very useful to the senior and graduate university students of software engineering and computer science.
Contents
Chapter 1 provides an overview of object technology and introduces the terms most commonly used in this field. Chapter 2 looks at the application development environment. Chapter 3 covers the analysis and design activities in a object-oriented environment and categorizes the different approaches that practitioners in the field advocate, while Chapter 4 takes up implementation issues. Chapter 5 addresses the complexities of building a user interface and the concepts and applications of visual programming tools.
Chapter 6 introduces VMT, an integrating object methodology. Chapter 7 discusses the process of building an object-oriented application and the teamwork required, while Chapter 8 delves into the reuse constructs, called frameworks, and their usefulness for productive application development. Chapter 9 reviews the requirements for persistent information in an object-oriented environment and the solutions provided by object databases. Chapter 10 analyses the ongoing efforts to standardize the treatment of objects in order to facilitate compatibility across languages and platforms. Chapter 11 discusses the issues involved in managing the staffing object-oriented applications development projects, and the structure and justification of a reuse organization. Finally, Chapter 12 provides a road map to application development, compatible with information modeling concepts.
Acknowledgments
This book is the result of the work done in the field of object technology at the IBM International Technical Support Center in San Jose, California. It includes the results of projects run at the Center, and sharing information and experiences with the IBM software laboratories of Santa Teresa, California, Cary, North Carolina, Rochester, Minnesota, and Toronto, Canada. In addition, fruitful and stimulating exchanges have taken place with the IBM Object-Oriented Technology Center (OOTC), the IBM US Object-Oriented Consulting organization, and the IBM UK Know How Consultancy and Services Group. The projects at San Jose were staffed with specialists from IBM organizations of many countries, who contributed with their work and experience.
The first version of this book was published in 1992 by the same authors as an IBM ITSO publication (known as a "redbook"). The present edition reflects the changes in the technology that have occurred since then and expands on many topics, providing a somewhat different perspective on many of them, as a result of practical experiences and the maturing of viewpoints. It is impossible to name everyone who influenced our thinking, but we want to acknowledge the following people: Dr. Paul Luker of California State University, Chico, for his detailed and precise comments that enhanced the book's contents; Walter Fang (IBM ITSO) and Andy So (IBM Consulting Group) for their ideas and drawings; Ghica van Emde Boas Lubsen (IBM Netherlands) for her contributions to the first edition's Chapters 2, 11 and Appendix C. Many consultants and specialists in IBM organizations and in client teams helped us focus on the most important issues of the implementation of object-orientation in the real world of information technology.
This work would not have been possible without the active support of Brett Paskin, ITSC San Jose AD Manager. Norm Zimmerman, ITSO director, provided an environment of empowerment that allowed new ideas to blossom and bear fruit.
Second Edition Acknowledgments
Many people helped ensure the quality and usefulness of the second edition. We thank each of them for their contribution. Brian Henderson-Sellers, University of Technology-Sydney, and Ghica van Emde Boas, IBM Netherlands both reviewed portions of the book. Rachel Lau, IBM Consulting Group-Hong Kong coded the IBM Smalltalk version of the sample application. Thanks also to Masami Moriya, IBM Japan, who supported the creation of the Japanese language edition of the book. A very special thanks to Jens Tiedermann, ITSO-San Jose Center Manager whose support allowed the second edition to happen. And thanks to the staff at Addison-Wesley, especially Christine Kulke, Teri Holden and Carter Shanklin for their key roles in the success of this book.
D. S. T.
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