Book Image

Working with Legacy Systems

By : Robert Annett
Book Image

Working with Legacy Systems

By: Robert Annett

Overview of this book

The IT industry is constantly evolving with the introduction of new technologies. While it is important to keep up with advancements, maintaining legacy systems is equally necessary to ensure that the infrastructure of your organization functions to the best of its ability. Sound knowledge of techniques that can be used for maintaining legacy systems can help you avoid common pitfalls. The book begins with a quick overview of what a real legacy system looks like, how it works, and common issues that may be faced when trying to maintaining it. You'll then explore the architecture of a legacy system in detail and understand each of its components. As you progress, you'll discover a variety of techniques for analyzing a legacy system and how to apply them. Once you get to grips with the security constraints associated with legacy systems, you'll explore ways to secure them. Finally, you'll be able to easily make changes in legacy systems to enhance their performance. By the end of this book, you’ll have developed the skills and confidence to work with legacy systems and efficiently maintain them.
Table of Contents (7 chapters)

Appendix A. Example Legacy Scenario

A Very Brief Overview

The salient points:

  1. You work for a furniture company

  2. You get a promotion!

  3. You are now responsible for the warehouse inventory system...

  4. No one has touched it for a while

  5. It was written in 2003

  6. It’s a 3-tier architecture

  7. It basically works, although people moan about it.

  8. What do you do?

Why this example?

Most organizations are not primarily focused on technology! One of the reasons I have picked a furniture company is that any IT systems they have will support the main business rather than being the revenue driver. This is true for most IT systems in most organizations – web companies selling online services are not representative.

You have found yourself responsible for this system and discovered that no one has developed (or performed maintenance) programming on this system for a while. However, the system is used and performs an important and core (supporting) function within the business – no one gets their furniture if the warehouse is not operating correctly.

How should you respond to the situation you find yourself in and what problems are you likely to face? What are the strategies you should employ and how should you execute them?

It’s very difficult to get a good impression of what this system does, who uses it, and how they use it from the description above (or any text-only description). Hopefully, the diagrams and sketching techniques used in the planning chapters demonstrated how useful they can be.