Globalization, technological advances, easy access to information, and new contemporary management styles increase the success of the business and ensure that it is among the good companies, but does not ensure that it is among the perfect companies. Transforming businesses from good companies into excellent companies and continuing this for many years depends on their managers and employees. When all businesses that have transformed from good to excellent are examined, it is seen that the managers of all of them are Level 5 managers. Jim Collins states that the most important factor in turning good companies into great companies is managers. In excellent companies, it does not matter whether their managers are famous or very popular, whether they are the best CEOs, whether they apply the latest technology or catch up with the changes required by the age. The important thing is to implement a culture of discipline by focusing on the right target with the right 174 | Nurgül Erdal h t tp : / / de r gi p ar k . go v . tr / a i c us be d 1 0/ 1 N i s a n / Apr i l 2 02 4 people. In this book, Jim Collins reveals how a mediocre company can permanently transform into a great company. As can be understood from here, it is emphasized that the most important resource of the business is the right people and that these right people must be managed by Level 5 leaders to achieve the goals of the business. The book "How to achieve permanent success from "Good" to "Excellent" Company is a sourcebook for all businesses and management science. It is also recommended as a textbook for all business management students. Key Words: Excellent company, good company, manager, success, Jim Collins, 5. level leadership