This is the best book to get understanding about the essence of teamwork, especially beneficial for Agile coach, Scrum Master, Head of Departments, COO, CEO … The book is a fable about Kathryn, new chairman of the Decision Tech and her senior executives Team. In the first part, Kathryn shows her team a comprehensive insight of whether or not a team is functioning healthily, introduce the pyramid dysfunction model of a Team.
After that, the fable is about Decision Tech senior executives team meetings where Kathryn step by step gets others to overcome the dysfunctions and build a strong team.
In the end, the book provides the team questionnaire as a simple tool to determine which dysfunctions are present in the team. However, how much the questionnaire can help to exactly discover a Team dysfunction is questionable. I did some online surveys of a Team dysfunction, the data was not so insightful.