Preface

In more than 20 years on projects and five years in the classroom, I've seen a lot of things change and a lot of things stay the same. I've watched people get thrown in every direction by the speed and impact of changes in technology, and I've listened to the same unchanging list of complaints:

• Poorly defined requirements
• Rapidly changing requirements
• Difficulties among IT and business team members and clients
• Estimates that can't be trusted because they are actually individualized guesses because no one has kept any development metrics
• The overwhelming challenge of maintaining existing systems with no documentation

So how can the Unified Modeling Language help solve these problems? UML has become an increasingly popular and powerful component of software development strategies around the world. More than 90 percent of the Fortune 500 companies use it in some form. Why? Because UML supplies some essential tools that support a professional response to these challenges. UML provides