This document provides an overview of object-oriented analysis and design (OOAD). It discusses key OO concepts like classes, objects, encapsulation, and polymorphism. The document also outlines the unified process methodology for OO software development. This methodology uses use cases to capture user needs and a layered architecture with user interface, business, and access layers. The benefits of the OO approach include reuse, maintainability, and aligning software design with the real world.