From the SEI, a practical roadmap that allows readers to deliver improved business value through modernizing legacy software systems. Softcover.

Robert Seacord began programming (professionally) for IBM in 1982 and has been programming in C since 1985, and in C++ since 1992. Robert is currently a Senior Vulnerability Analyst with the CERT/Coordination Center at the Software Engineering Institute (SEI). He is coauthor of Building Systems from Commercial Components (Addison-Wesley, 2002) and Modernizing Legacy Systems (Addison-Wesley, 2003). The CERT/CC, among other security-related activities, regularly analyzes software vulnerability reports and assesses the risk to the Internet and other critical infrastructure.

Daniel Plakosh is a senior member of the technical staff in the COTS-Based Systems initiative at the SEI. Prior to joining the SEI, he was the lead software engineer for the Systems Engineering Department at the Naval Surface Warfare Center (NSWCDD).

Grace A. Lewis is a member of the technical staff at the SEI. Before joining the SEI, she was Chief of Systems Development for Icesi University in Cali, Colombia.

Software systems become legacy systems when they begin to resist modification and evolution. However, the knowledge embodied in legacy systems constitutes a significant corporate asset. Assuming that these systems still provide significant business value, they must then be modernized or replaced. This book describes a risk-managed approach to legacy system modernization that applies a knowledge of software technologies and an understanding of engineering processes within a business context. AudienceModernizing Legacy Systems: Software Technologies, Engineering Processes, and Business Practicesshould be useful to anyone involved in modernizing a legacy system. For asoftware engineer,the book should help you understand some of the larger business concerns that drive a modernization effort. For asoftware designer,this book should help you understand the impact of legacy code, coupled with incremental development and deployment practices, on design activities. For asystem architect,this book explains the processes and techniques that have failed or succeeded in practice. It should also provide insight into how you can repeat these successes and avoid the failures. For anIT manager,this book explains how technology and business objectives influence the software modernization processes.In particular, the book should help you answer the following questions: When and how do I decide whether a modernization or replacement effort is justified? How do I develop an understanding of the legacy system? How do I gain an understanding of, and evaluate the applicability of, information system technologies that can be used in the modernization of my system? When do I involve the stakeholders, and how can I reconcile their conflicting needs? What role does architecture play in legacy system modernization? How can I estimate the cost of a legacy system modernization? How can I evaluate and select a modernization strategy? How can I develop a detailed modernization plan? Organization and ContentModernizing Legacy Systems: Software Technologies, Engineering Processes, and Business Practicesshows how legacy systems can be incrementally modernized. It uses and extends the methods and techniques described inBuilding Systems from Commercial ComponentsWallnau 01 to draw on engineering expertise early in the conceptual phase to ensure realistic and comprehensive planning.This book features an extensive case study involving a major modernization effort. The legacy system in this case study consists of nearly 2 million lines of COBOL code developed over 30 years. The system is being replaced with a modern system based on the Java 2 Enterprise Edition (J2EE) architecture. Additional challenges include a requirement to incrementally develop and deploy the system. We look at the strategy used to modernize the system; the use of Enterprise JavaBeans, message-oriented middleware, Java, and other J2EE technologies to produce the modern system; the supporting software engineering processes and techniques; and the resulting system.Chapter 1 provides an introduction to the challenges and practices of software evolution. Chapter 2 introduces the major case study in the book. Chapter 3 introduces the risk-managed modernization (RMM) approach, which is elaborated in Chapters 4 through 17 and illustrated by the case study. At the beginning of Chapters 4 through 17, we provide an activity diagram of RMM as a road map to the chapter. Chapter 18 provides some recommendations to help guide your modernization efforts, although these recommendations cannot be fully appreciated without reading the main body of the book.Throughout this book, we use the Unified Modeling Language (UML) to represent architecture drawings and design patterns. A brief introducti