This book is written for students and developers who wish to master the essential skills and techniques in applying the Unified Modeling Language (UML) for software development. The reader will learn object-oriented analysis, design, and implementation using appropriate UML models, processes, techniques, and tools. Accompanying this book is the Community Edition of Visual Paradigm for UMP (VP-UML), an award-winning Computer-Aided Software Engineering (CASE) tool, which allows the reader to put the theories learned into practice immediately. The authors propose a novel framework for modeling and analysis called the View Alignment Techniques (VAT), which helps software developers create development methods. The Activity Analysis Approach (A3), which is particularly suited for the development of interaction-intensive systems, is described. These concepts have been well proven, as they were followed closely in the development of the VP-UML CASE tool. Three chapters in this book describe structural, use case, and dynamic modeling and analysis techniques, together with practical tricks and tips that have been gained by the authors from many years of experience. Each of these three chapters includes a mini-case study which illustrates the unique from diagram to code concept in software development. In the final chapter, a major case study is included to help the reader reinforce the theories learned in previous chapters using VP-UML. The key areas in object-oriented technology covered in the book include: Requirements modeling using use cases: Identifying, capturing, and elaborating requirements. Domain analysis for object identification: Building structural models for objects and their attributes and relationships. Dynamic analysis and design: Building dynamic models, refining structural models, and making design decisions. Implementation: Translating UML models into codes and implementations. Method creation and the framework of VAT: Choosing the right UML models and customizing the design and analysis process. A case study: Showing how A3 is put into practice, using VP-UML.