A management book where Jim Collins and his research team studied 11 companies that made the transition from being good to becoming great over a span of 15 years.

"Good to Great" is a management book written by Jim Collins, published in 2001. In the book, Collins and his research team studied 11 companies that made the transition from being good to becoming great over a span of 15 years. These companies were compared to similar ones that didn't make the leap to greatness. The aim was to identify what factors and strategies differentiated the "great" companies from the merely "good" ones.

Here are some key concepts from "Good to Great":

1. Level 5 Leadership: Collins introduces the concept of Level 5 Leadership, which refers to leaders who blend personal humility with professional will. They are ambitious for their companies rather than for themselves.

2. The Hedgehog Concept: The Hedgehog Concept is based on the ancient Greek parable of the hedgehog and the fox. It suggests that great companies focus on what they can be the best in the world at (their Hedgehog Concept), rather than trying to be everything to everyone.

3. The Flywheel Effect: Collins introduces the idea of the flywheel, representing the cumulative effect of consistent, small actions over time that ultimately lead to breakthrough success.

4. First Who, Then What: Collins emphasizes the importance of getting the right people on the bus (the company), in the right seats, before figuring out where to drive it. Having the right people in key positions is crucial for long-term success.

5. Confront the Brutal Facts (Yet Never Lose Faith): Great companies confront the harsh realities of their situation, but they maintain an unwavering belief that they can and will prevail in the end.

6. Technology Accelerators, Not Drivers: Collins argues that technology should be seen as an accelerator of momentum, rather than a driver of it. Companies that become great use technology strategically to amplify their Hedgehog Concept.

"Good to Great" has been influential in the business world for its rigorous research methodology and its actionable insights on how companies can achieve sustained greatness. It's become a staple for leaders and managers seeking to improve their organizations.