LEGACY SYSTEMS: TRANSFORMATION STRATEGIES
By William M. Ulrich
Legacy Transformation Strategies Book
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Description:
This book is about legacy information architectures and the
daunting challenges they pose, along with strategies for tackling these
problems. Commercial application systems and data architectures, running in
production computing environments, are the lifeblood of the enterprise. These
giant infrastructures manage business and government operations around the
globe. Any organization that believes it can address critical information
requirements by replacing, wrapping or ignoring legacy information assets is
headed for a train wreck of monumental proportions.
Legacy application systems are defined as any production enabled software, regardless of the platform it runs on, language it is written in or length of time it has been in production. Legacy data structures are defined as the enterprise data that is accessed and modified by these production application systems. Collectively, these systems and data structures form critical information assets that managers and analysts must strive to understand, modify, consolidate, migrate or otherwise transform to meet critical business requirements.
Despite the vast changes in information technology (IT) in recent years, legacy information challenges have remained. Improvements in business modeling, analysis, design and development, component reuse and Web-enabled architectures hold great promise. Yet the value of these advancements will be minimal if management does not address legacy architectures under a cohesive, parallel strategy.
Worldwide, there are well over 200 billion lines of software that are fragmented, redundantly defined, hard to decipher and highly inflexible. These systems, which have been functioning for decades, have survived revolutions in software, hardware and the Internet. Now, with IT on the cusp of a new era where handcrafted coding techniques are being supplanted by component-based development and Web Services, organizations run the risk of being mired down by a mountain of legacy code.
Efforts to address the legacy challenge have had limited impact. Over the past few years, stovepipe applications and data structures have been the target of piecemeal integration. While offering some near-term value, middleware and related wrapper-based solutions limit an enterprise�s ability to leverage, reuse and fully incorporate critical business rules and data locked inside of legacy architectures.
Countless companies are struggling to incorporate back-end functionality into front-end applications. Insurance companies would like to Web-enable claims processing environments. Banks would like to fully deploy on-line banking solutions. Telecommunication firms need to consolidate customer applications to help prepare for entering new markets. Energy companies, health care providers, retailers and a wealth of other industry sectors must deliver immediate and comprehensive solutions to customers faster and more effectively. Even government agencies have entered the new e-business sector.
Essential legacy functionality and data can be identified, extracted and reused under emerging information architectures to meet customer and user demands. This will only occur, however, if organizations take a proactive approach to tackling the legacy challenge and this requires a legacy architecture transformation strategy. This book delivers such a strategy along with practical planning and implementation advice to those haunted by difficult legacy challenges and seeking quantifiable solutions.
SUMMARY OF CONTENTS
PART ONE: LEGACY TRANSFORMATION: BACKGROUND & STRATEGIES
Chapter one introduces the origins and evolution of computers and the software that directs the activities of those computers. It also exposes the chasm between what people think computers can do and how most computers currently function.
Chapter two defines the issues organizations face when trying to understand and change the core applications that manage day-to-day business operations. This chapter helps place the significance and scope of the legacy challenge in perspective and refutes the belief that legacy applications can be ignored, easily replaced or just wrapped in middleware. Case histories demonstrate that failed information initiatives can be traced directly back to the inability of an enterprise to effectively manage change requirements within legacy computing environments.
Chapter three discusses the changing face of information technology by introducing the world of the Internet, Java, Web Services and a host of other emerging disciplines. This modern world of perfection runs in sharp contrast to the world of legacy information architectures.
Chapter four introduces various strategies for managing, integrating and transforming legacy application environments. This chapter introduces the concept of business-driven transformation, discusses transformation as a risk management tool, outlines a transformation framework and provides project planning templates. It also provides an overview of the transformation approaches and techniques that are the foundation for the remaining sections of this book.
PART TWO: INFRASTRUCTURE SETUP & PLANNING
Chapter five discusses the business and information management infrastructure needed to deliver legacy transformation solutions. This chapter delves into the infrastructure issues responsible for creating the current legacy architecture dilemma. It also provides organizational transformation guidelines needed to address the legacy systems challenge and avoid recreating it at some point in the future. Chapter five also outlines how to create a culture of reuse, project roles and responsibilities, and the part that methodologies, repositories, metrics and software tools play in a transformation effort.
Chapter six discusses how to plan and justify legacy transformation projects. This includes issues such as total cost of ownership, techniques for determining return on investment (ROI) and ways to redefine the concept of "value" in an ROI effort. In addition, this chapter discusses collaborative planning concepts, project and team formation, the concept of "dual positioning" transformation ROI, how to learn from our failures, infrastructure justification and project ROI.
Chapter seven introduced the various technologies that an organization can use to plan, analyze, execute and validate a transformation project. This includes the underlying foundation and various approaches used by these tools as well as an overview of various tool categories. This chapter also discusses the pros and cons of using certain tools for various transformation tasks and tool identification and procurement strategies.
Chapter eight details the tasks involved in performing the enterprise and the project level assessment. The enterprise assessment forms the basis for creating a transformation strategy or deploying a large-scale transformation initiative � such as a cross-functional package implementation. The project level assessment begins the detailed analysis required to launch and finalize a transformation implementation project.
PART THREE: TRANSFORMATION IMPLEMENTATION
Chapter nine provides a transformation-oriented perspective on various enterprise application, business-to-business and business process integration scenarios. This includes outlining integration options and approaches that can be pursued over the interim and in conjunction with strategic transformation projects.
Chapter ten provides detailed approaches and techniques for improving application source code and data structures without the need to redesign those structures. These discussions are provided within a context of providing near-term value to the users and beneficiaries of those systems and data structures.
Chapter eleven delves into data and business rule transformation options and techniques. This chapter provides a comprehensive discussion of legacy architecture reverse engineering, reengineering and reconstruction. This discussion incorporates current-to-target mapping, data and business rule extraction, reuse in target architectures and related topics.
Chapter twelve ties together the strategies, approaches and techniques presented in previous chapters under case study oriented scenarios. These scenarios include application consolidation, multi-system integration, application package selection and deployment, middleware deployment, rehosting, data migration and component migration.
APPENDIX A
Appendix A provides a sample list of vendors that offer software and services that can help leverage transformation initiatives. These are only a sampling of vendors and not a complete or fully updated list. The author is not recommending these vendors, only identifying their availability and the fact that they have certain tools that address legacy transformation challenges.
Download the latest Appendix A update to William Ulrich's book - Legacy Systems: Transformation Strategies. This new Appendix to Mr. Ulrich's book contains many new tool and vendor listings for performing modernization work on existing systems.