Excerpts

About this book The aim of this book is to take you through the process of object-oriented (OO) analysis and design using the Unified Modeling Language (UML) and the Unified Process (UP). UML provides the visual modeling language for OO modeling, and UP provides the software engineering process framework that tells you how to perform OO analysis and design. There is a lot to UP, and in this book we present only those aspects directly pertinent to the work of the OO analyst/designer. For details on the other aspects of UP, you should refer to Rumbaugh 1 and the other UP books in the bibliography. In this book we show you enough UML and associated analysis and design techniques so that you can apply modeling effectively on a real project. According to Stephen J Mellor Mellor 1, there are three approaches to UML modeling. UML as a sketch - this is an informal approach to UML where diagrams are sketched out to help visualize a software system. It's a bit like sketching an idea for something on the back of a napkin. The sketches have little value beyond their initial use, are not maintained, and are finally discarded. You typically use whiteboards or drawing tools such as Visio and PowerPoint (www.microsoft.com) to create the informal sketches. UML as a blueprint - this is a more formal and precise approach whereby UML is used to specify a software system in detail. This is like a set of architect's plans or a blueprint for a machine. The UML model is actively maintained and becomes an important deliverable of the project. This approach demands the use of a real modeling tool such as Rational Rose (www.rational.com) or MagicDraw UML (www.magicdraw.com). UML as executable - using Model Driven Architecture (MDA), UML models may be used as a programming language. You add enough detail to UML models so that the system can be compiled from the model. This is the most formal and precise use of UML, and, in our view, it is the future of software development. In this approach, you need an MDA-enabled UML tool such as ArcStyler (www.arcstyler.com). MDA is beyond the scope of this book, although we discuss it briefly in Section 1.4. Our focus in this book is on UML as a blueprint. The techniques you learn will also apply to using UML as an executable. Having learned UML as a blueprint, you will naturally be able to use UML as a sketch should you need to. We have tried to make our presentation of UML and UP as straightforward and accessible as possible. Conventions To help you navigate through the book we have provided each chapter with a roadmap in the form of a UML activity diagram. These diagrams indicate reading activities and the order in which sections might be read. We cover activity diagrams in detail in Chapter 14, but Figure 1 should be sufficient to let you understand the roadmaps. Most of the diagrams in this book are UML diagrams. The annotations, in blue, are not part of UML syntax. We have provided notes in the margin to highlight important information. We have used the UML note icon for this. Who should read this book We can think of several possible readers for this book. You are an analyst/designer who needs to learn how to perform OO analysis and design. You are an analyst/designer who needs to learn how to perform OO analysis and design within the framework of the Unified Process. You are a student taking a UML course at a university. You are a software engineer who needs a UML reference. You are a software engineer taking a UML training course, and this is your course book. Clear View Training provides a four-day UML training course based on this book. This course is given throughout Europe by our partners, Zuehlke Engineering (www.zuhlke.com), and is available for licensing. If you are an academic institution using this book as your course book, you can use our training course for free. See www.clearviewtraining.com for more on commercial and academic licensing. How to read this book So many books, so little time to read them all! With this in mind we have designed this book so that you can read it in several different ways (as well as cover to cover) according to your needs. Fast track Choose Fast Track if you just want an overview of the whole book or a particular chapter. This is also the "management summary". Choose a chapter. Read the chapter roadmap so that you know where you're going. Go through the chapter looking at the figures and reading the margin notes. Read the "What we have learned" section. Go back to any section that takes your interest and read it. Fast Track is a quick and efficient way to read this book. You may be pleasantly surprised at how much you can pick up! Note that Fast Track works best if you can first formulate a clear idea of the information you want to obtain. For example "I want to understand how to do use case modeling." Reference If you need to know a particular part of UML or learn a particular technique, we have provided a detailed index and table of contents that should help you locate the information you need quickly and efficiently. The text is carefully cross-referenced to help you to do this. Revision There are two strategies for revision with this text. If you need to refresh your knowledge of UML as quickly and efficiently as possible, read the outline summaries of each chapter in the "What we have learned" section. When you don't understand something, go back and read the appropriate section. If you have more time, you can also browse through each chapter studying the diagrams and reading the margin notes. Dipping If you have a few minutes to spare, you might pick up the book and open it at random. We have tried to ensure that there is something interesting on every page. Even if you already know UML quite well, you may still discover new things to learn. 0321321278P06172005 Excerpted from UML 2 and the Unified Process: Practical Object-Oriented Analysis and Design by Jim Arlow, Ila Neustadt All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.