This report provides an in-depth analysis of organisational behaviour, focusing on the case of Marks & Spencer (M&S). It begins by examining how organisational culture, power dynamics, and political influences affect individual and team performance. The report utilizes Handy's cultural typology and French and Raven's bases of power to evaluate M&S's environment. Furthermore, it explores various motivational theories, including Maslow's hierarchy of needs and Vroom's expectancy theory, and their application in achieving organisational goals. The report also differentiates between effective and ineffective teams and discusses the impact of organisational behaviour concepts and philosophies on team behaviour. Finally, it offers a critical evaluation of team development theories within the context of M&S, providing recommendations for fostering a positive and productive work environment. The report aims to offer insights into how these factors influence employee behaviour and overall organisational success.