This document provides an overview of organisational behaviour. It discusses how OB seeks to understand individual, group, and organisational behaviour using scientific methods. Key topics covered include early management theories from Adam Smith to Frederick Taylor's scientific management. It also summarizes research from the Hawthorne studies and classical organisation theorists like Fayol, Weber, and Barnard. The document traces the development of OB from its classical roots to modern behavioural and contingency perspectives, noting changing challenges with globalization, diversity, and new forms of work and organization.