Object Design: Roles, Responsibilities, and Collaborations (Paperback)

~ (Author), Alan McKean (Author)

Editorial Reviews

Product Description

After more than ten years, object technology pioneer Rebecca Wirfs-Brock teams with expert Alan McKean to present a thoroughly updated, modern, and proven method for the design of software. The book is packed with practical design techniques that enable the practitioner to get the job done. Like many human endeavors, design is part art, part engineering, part guesswork, and part experimentation. Discipline, hard work, inspiration, and sound technique all play their part as well. For any given problem, there are many reasonable, but only a few very good solutions. The authors' goal is to help readers learn to make those very good design decisions on their own. The book explores challenges that software developers will face as they build their design, and shows how design patterns can be used to solve design problems. Long awaited and eagerly anticipated, this book represents the first great software design book of the century. A FUTURE CLASSIC!

From the Back Cover

If you create software using object-oriented languages and tools, then Responsibility-Driven Design has likely influenced your work. For over ten years Responsibility-Driven Design methodology has been the standard bearer of the behavioral approach to designing object-oriented software. Object Design: Roles, Responsibilities, and Collaborations focuses on the practice of designing objects as integral members of a community where each object has specific roles and responsibilities. The authors present the latest practices and techniques of Responsibility-Driven Design and show how you can apply them as you develop modern object-based applications.

Working within this conceptual framework, Rebecca Wirfs-Brock and Alan McKean present how user requirements, system architecture, and design patterns all contribute to the design of an effective object model. They introduce a rich vocabulary that designers can use to discuss aspects of their designs, discuss design trade-offs, and offer practical guidelines for enhancing the reliability and flexibility of applications. In addition, case studies and real-world examples demonstrate how the principles and techniques of Responsibility-Driven Design apply to real-world software designs.

You'll find coverage of such topics as:

Strategies for selecting and rejecting candidate objects in an emerging design model

Object role stereotypes and how to identify objects' behaviors

How to characterize objects using role stereotypes

Allocating responsibilities to appropriate objects

Developing a collaboration model

Strategies for designing application control centers

Documenting and describing a design, focusing on use cases, design conversations, and annotations

Strategies for enhancing reliability, including handling exceptions and recovering from errors

How to characterize software variations and design to support them for greater flexibility

How to categorize and treat various kinds of design problems

As all experienced designers know, software design is part art and inspiration and part consistent effort and solid technique. Object Design: Roles, Responsibilities, and Collaborations will help all software designers--from students to seasoned professionals--develop both the concrete reasoning skills and the design expertise necessary to produce responsible software designs.

0201379430B08292002

See all Editorial Reviews

Product Details

• Paperback: 416 pages
• Publisher: Addison-Wesley Professional (November 18, 2002)
• Language: English
• ISBN-10: 0201379430
• ISBN-13: 978-0201379433
• Product Dimensions: 9 x 7.4 x 0.9 inches
• Shipping Weight: 1.8 pounds (View shipping rates and policies)
• Average Customer Review: 4.4 out of 5 stars  See all reviews (12 customer reviews)
• Amazon.com Sales Rank: #581,430 in Books (See Bestsellers in Books)

Customer Reviews

Most Helpful Customer Reviews

34 of 34 people found the following review helpful:

5.0 out of 5 stars Very Good Text on Object Design, January 23, 2003

By	David C. Veeneman (Lincolnshire, IL USA) - See all my reviews (REAL NAME)

I think I finally have a handle on object modeling-- 'Object Design' deserves a lot of the credit.

I have a shelf full of books on UML, uses cases, patterns, and modeling. I spent almost a year struggling through UML, trying to understand the nuances of sequence diagrams versus collaboration diagrams. Meanwhile, I felt no closer to being able to create serviceable object models for my projects.

Rebecca Wirfs-Brock and Alan McKean dispense with much of the tedious diagramming one usually associates with object modeling. Instead of charts and relationships, the book focuses on the roles, responsibilities, and behaviors that define an object. If you have ever assembled and managed employee teams, the framework will be very fmailiar. And that's where I found my breakthrough.

The book offers a good introduction to object modeling for those new to the area, and a solid reference for those looking to stremline their current methodology. The processes suggested by the authors are simple and flexible. But they are powerful enough to handle even complex designs.

One of the strongest pieces of advice in the book is to avoid rushing into UML software--stick with index cards until the design is fairly well developed. That's what got me out of a morass of charts and diagrams that looked nice, but did relatively little. I'd paraphrase the book's theme as "Forget the formalism and focus on your application's responsibilities, and how those responsibilities can be allocated among cohesive, well-organized team players.:

The book is language neutral--it's focus is design, rather than programming. The design methodology taught in the book should be easily adaptable to nearly any object-oriented programming language.

I have no hesitation recommending Object Design to novice and intermediate object modelers. I rate is as the best book I have read on the design and modeling of object-oriented systems.

13 of 13 people found the following review helpful:

5.0 out of 5 stars A great first text on OO design, July 28, 2004

By	wiredweird "wiredweird" (Earth, or somewhere nearby) - See all my reviews (TOP 100 REVIEWER)

Amazon Verified Purchase

Wirfs-Brock and McKean have written an oustanding introductory book on object-oriented design. This is definitely a book for beginning OO programmers, the ones who aren't sure how to assign functions to objects and who aren't ready for design patterns yet. More experienced developers won't get much out of it, but that's OK. Every level needs its own reference books.

The book's layout and illustrations present its content well. UML diagrams, for example, use one color and typeface for the actual UML notation. The same diagrams use a different color and typeface for notes that explain the UML. Unlike other books, there's no confusion about which is the tool and which describes the tool. The text is gentle and reasonably jargon-free, but I think it over-does the friendliness in places. In discussing a program's normal and exception handling behavior, the term "happy path" described the execution in the absence of errors. The term may be evocative, but is just a bit hard to take seriously.

The sequence of topics makes good sense. It starts with the idea of a "responsibility," the basic unit of application logic. The authors develop this into strategies for defining objects, defining relationships between objects, and defining the control strategies that implement those relationships. They continue on through error handling (reliability) and extensibility - handling of future features. Throughout, the authors keep a moderate, pragmatic tone, free of name-brand methodology. That's a good thing, since the real focus is on basic skills and decision criteria.

One aspect of this book is just a little confusing. It's definitely aimed at educating a new OO designer, but it doesn't lay out its educational objectives or plan very clearly. It certainly lacks the didactic rigor of a textbook. It would make a good supplementary text, though, and it might be very helpful to a novice working with more experienced developers. Best of all, it refers to additional texts (including Strunk and White!) that will help claify the programs as well as communication with other members of the programming team.

This book is great for anyone starting OO design on their own. It's also good for classroom students who just aren't getting it from their regular instructor and text. Experienced developers won't find much new here, except very clear descriptions of how much error handling or flexibility is enough.

//wiredweird

13 of 13 people found the following review helpful:

5.0 out of 5 stars Definitive guide to Object Oriented Design, July 20, 2003

By	T. Evans - See all my reviews (REAL NAME)

I've always believed the best approach to object-oriented design is Responsibility Driven Design (RDD), and this is the best book on the subject-written by the inventor of RDD.

I recently showed Mike Rosen, of Cutter Consortium, Object Design. Before I could say it had great chapters on RDD plus work on design for reliability and flexibility plus pages of references to related books and papers, he said 'Great! This will be my next book purchase'.

So, why is Object Design: Roles, Responsibilities, and Collaborations (OD) a really great book? These folks have years of design consulting and teaching experience, know what they are talking about, and are good at telling the story.

OD is a great read from cover to cover. Their two-chapter review of object design concepts was energetic, insightful, and comprehensive. From the beginning they are mixing in CRC cards (Thanks Kent, Ward!), architecture styles, patterns, and stereotypes into the discussion. This is the place to start for novices and intermediate students, and professionals now have the definitive reference book on object oriented design.

The authors understand we all have different learning styles. Along with their conversation, the first two chapters also illustrate concepts and examples with over 20 figures, a couple of UML diagrams, three (short) Java code blocks, and eight CRC card drawings. Concrete examples are provided throughout the book, from computer speech to finance and telecommunications.

The Chapter titles are: 1 Design Concepts, 2 Responsibility Driven Design, 3 Finding Objects, 4 Responsibilities, 5 Collaborations, 6 Control Style, 7 Describing Collaborations, 8 Reliable Collaborations, 9 Flexibility, and 10 On Design. Each chapter includes a summary. The recommendations for further reading provide a guided tour of related works in software engineering, design, and general literature.

The authors share how they think about the critical areas of design for flexibility and reliability. So how do you build reliable systems? What are some experience-based guidelines for dealing with error conditions? What about all those exceptions anyway?! The chapter on flexibility is for me the heart of object technology. They show how you can apply object technology to give users control over their world. The analysis of hot spots or flex points guides the focused introduction of added flexibility. Then you can actually deliver on the promise of object oriented software.

Practitioners will find this book "spot on" for the treatment of UML and Patterns. So, yes, with three or more UML books on the shelf, I am sure you can draw all those diagrams - right? With OD you are learning to think in objects and to communicate your story. Your learning how to tell your story with UML, what to say visually and what not to say. OD is a pretty good source for UML notation guidance too, as the text and the diagrams are meticulously accurate, down to the arrow head styles. OD provides a good introduction to patterns and weaves a number of the more interesting GOF patterns into the design examples. Patterns are also emphasized in the chapter on flexibility.

Paraphrasing Ivar Jacobson's words from the forward: "this higher-level view of design, which focuses on responsibilities...helps you step away from implementation details and focus on what the appropriate software machinery should be..." In closing he writes: "Whether you are new to object technology or an experienced developer, this book is a rich source of practical advice."

These common sense lessons are essential for practitioners of design and systems architecting in all fields.