How to Transform Legacy Systems into Object Oriented Systems

How to Transform Legacy Systems into Object Oriented Systems

Hernan Cobo (Universidad Nacional del Centro de la Pcia. De Bs., Argentina) and Virginia Mauco (Universidad Nacional de Centro de la Pcia. De Bs., Argentina)
Copyright: © 2000 |Pages: 23
DOI: 10.4018/978-1-878289-67-4.ch007
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The OO paradigm is the predominant software trend of the 1990s. According to the literature, it provides a unifying model for various phases of development, facilitates system integration, allows prototyping, encourages software reuse, eases system maintenance and provides support for extensibility (Meyer, 1997). An OO system is best developed starting with OO analysis. However, some times this may be difficult because of the existence of so many systems developed 20 or more years ago, which are still used. These systems are called legacy and may be defined as large software systems people do not know how to cope with, but they are vital to organizations (Bennett, 1995). Hence, the decision on how to manage them is crucial because they may represent years of accumulated experience and knowledge. Besides, the software may be the only place where organizations business rules exist. Maintenance costs are a major issue with software (Pressman, 1992). Legacy systems maintenance is a difficult task because it is typical that during the maintenance process the structure and the documentation of the system deteriorate, making the maintenance progressively harder. It is essential to record the understanding of the system before it is forgotten and to structure it in such a way that it can be easily accumulated and retrieved. The development of new architectures and the improvements in programming methods and languages, have caused a need to reverse engineer and reengineer existing program code in order to get as much value as possible from legacy systems while exploiting the latest technology. This chapter describes a project whose aim is to develop a tool to transform legacy systems in order to simplify and improve their maintenance and understanding, taking benefit from OO technology. To achieve this, it is necessary to capture and recover all the knowledge extracted from imperative programs and store it in a higher level structure, which can be analyzed and manipulated. From this structure objects and classes are recognized and extracted to rewrite the program in an OO language. Besides preserving the original functionality, the new code generated should be structured, legible, modular, reusable, and more easily maintainable. The only source of information is programs imperative source code, and its quality has a great influence on the quality of the recovered objects. To minimize this influence, programs are first syntactically restructured and modularized. As part of this research, a prototype has been developed which implements the algorithms to restructure, modularize and extract objects automatically. Human intervention is allowed in order to improve the results.

Complete Chapter List

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Table of Contents
Chapter 1
Edward R. Sim
The ability to correctly identify system requirements is seen by most Information Systems (IS) researchers and practitioners as essential to the... Sample PDF
Object Oriented Requirements Analysis: Its Challenges and Use
Chapter 2
H. James Nelson, Kay M. Nelson, Mehdi Ghods, Holly E. Lee
The term structured methods refers to a philosophy of software development which emphasizes an adherence to a set of consistent rules or methods... Sample PDF
Building on Structured Design Techniques in the Object Oriented Environment
Chapter 3
Samuel K.A. Agyemang
Object oriented technology is still growing and has not yet matured. Many articles have been written on object oriented software development... Sample PDF
Object Oriented Testing in Software Development
Chapter 4
Jozsef T. Komlodi
Despite its decade long history, object database technology has never entered mainstream system development. In this work, I look at the background... Sample PDF
Technical and Market Viability of Object Database Technology
Chapter 5
Jane Fedorowicz, Denis Lee
Companies are increasingly requiring that new information systems development projects employ object oriented (OO) analysis, design and programming... Sample PDF
Software Reuse and Object Technology
Chapter 6
Gretchen Irwin, Chamini Wasalathantry
Object Oriented (OO) technology and software reuse are widely believed to be key ingredients to improving systems development productivity and... Sample PDF
Reuse in Object Oriented Modeling: An Empirical Study of Experienced and Novice Analysts
Chapter 7
Hernan Cobo, Virginia Mauco
The OO paradigm is the predominant software trend of the 1990s. According to the literature, it provides a unifying model for various phases of... Sample PDF
How to Transform Legacy Systems into Object Oriented Systems
Chapter 8
Gerold E. Cameron
This chapter will focus on the challenges and issues an organization faces when trying to integrate or migrate their legacy applications with more... Sample PDF
Challenges and Issues to Consider When Upgrading Legacy Applications
Chapter 9
Alex Podaras
Distributed objects, as applied to the term distributed object oriented systems, can be defined as those objects that have many locations on a... Sample PDF
Understanding Distributed Object Oriented Systems
Chapter 10
David H. Patton
Tomorrow’s business environment will make it increasingly difficult for businesses to operate efficiently. To gain the needed edge, in the global... Sample PDF
Distributed Object Business Engineering: Digital Legos for the Enterprise
Chapter 11
Luis F. Proano
This chapter is a review of journals and printed articles published during the last two years. It will give you an idea of the current needs in the... Sample PDF
What Are the Actual Industry Expectations and Needs with Regard to Object Oriented Technology?
Chapter 12
Robert M. Gittins
The rise of Object Oriented (OO) technologies has been nothing if not spectacular in the past few years. The IT world has witnessed the next... Sample PDF
Business Process Reengineering with Object Oriented Technology: Is the Gamble Worth the Risk?
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