This report provides an in-depth analysis of organizational behavior, focusing on the case study of Thomas Cook. It begins with an introduction to organizational behavior, defining its impact on group and team performance. The report then delves into leadership theories, evaluating their application and impact on organizational effectiveness. It explores various leadership styles such as autocratic, democratic, and laissez-faire, and their effects on employee motivation and productivity. The role of motivational theories, including McClelland's and Vroom's theories, is examined in the context of Thomas Cook. Furthermore, the report analyzes the company's organizational culture and structure, specifically highlighting its divisional structure and normative culture. It assesses different approaches to organizational decision-making, including rational, descriptive, and behavioral approaches, and evaluates management approaches to risk and uncertainty. The report concludes with a summary of key findings and their implications for organizational success.