An organisation's most important asset is its people. And critical to an organisation's success is the extent to which its people interact effectively - both with each other as team members and with the wider organisation. This is why managing teams has become a key area for a growing number of organisations around the world. While many organisations are world-class at managing their materials and machinery, they fall short in managing the human side of their activities.This book outlines the challenges faced by both team leaders and team members in 21st-century workplaces. It proposes 13 key performance or "team health" indicators for highly effective teams based on research data collected from a large range of industry sectors, team sizes and organisations in the UK. It contributes to the understanding of the nature and functioning of team cohesiveness by describing teamwork as a multi-component variable and identifying the factors that impact on teams and the implications of teamwork for organisations.The book sets out to aid organisations by introducing a Team Performance Diagnostic (TPD) tool. The TPD enables organisations to gain an accurate and detailed insight into the real-time performance of their teams, helps team managers to understand the underlying 'people' issues within the team and how to reach higher levels of team performance quickly. The TPD has been widely used in major multinationals and the UK public sector to pinpoint hard-to-find opportunities to achieve rapid improvements.The research suggests that the use of TPD contributes to more free-flowing feedback both within the team and in the organisation as a whole, and that successful teams are indicative of a healthy organisational culture.This book is an essential guide for senior managers and policy-makers dealing with team effectiveness, and will be highly useful for students of business and management.