Legacy systems : Transformation strategies

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 modern enterprise. These systems 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 beenfunctioning for decades, have survived revolutions in software, hardware, and the Internet. Now, with IT on the cusp of a new era in which 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 online banking solutions. Telecommunications 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.

• Pt. I Legacy Transformation: Background and Strategies
• Ch. 1 The Modern Enterprise and Legacy Architectures
• Ch. 2 Defining the Legacy Architecture Challenge
• Ch. 3 The Changing Face of Information Technology
• Ch. 4 Legacy Architecture Management and Transformation Strategies
• Pt. II Infrastructure Setup and Planning
• Ch. 5 Creating a Legacy Transformation Infrastructure
• Ch. 6 Planning and Justifying a Legacy Transformation Project
• Ch. 7 Legacy Transformation Technology
• Ch. 8 Enterprise and Project-Level Assessments
• Pt. III Transformation Implementation
• Ch. 9 Incorporating EAI, B2Bi, and BPI into a Comprehensive Integration Strategy
• Ch. 10 Structuring, Rationalizing, and Upgrading Legacy Applications and Data Structures
• Ch. 11 Logical Data and Business Rule Capture, Redesign, and Reuse
• Ch. 12 Transformation Project Strategies and Case Studies
• App Sample Tool Vendor List