The number one reason an employee leaves a company is because of their direct supervisor, usually a lack of communication. Most companies promote employees in their first supervisor or team leader roles because they are outstanding employees (they make the most widgets, take the most phone calls, etc.) and not because of their leadership abilities. Usually the companies fail to provide any type of training for these new leaders.
If we want managers to be successful in their role, we have to provide them with the necessary tools to communications training. The training is focused on HR and management basics to provide managers with a solid foundation to lead their groups.