Delegation - Utilise Employees
As a manager, it may be possible to keep control of a project yourself rather than trusting others to do some or all of it. But by not delegating and trusting your employees to work on the small projects or tasks, they will not learn the skills and confidence to successfully complete tasks on a bigger project when it is physically impossible for the manager to do everything themselves.
It is likely that many of the employees will have been at the company for longer than the manager themselves, and so will in fact have a more detailed knowledge of tasks and processes than the manager does, especially if it is a new manager that is just starting in the business/industry, or has been moved from a completely separate department of the same firm. This means that in fact, rather than not being able to be trusted, the employee could probably do the task better than the manager can.
The collective wealth of knowledge and experience of the employees working for the manager is a vital asset for a business and one that should not be ignored. Utilising this asset can provide tremendous benefits for a business; not only for completing tasks but also for new idea generation and improvements to processes and working practices.
Because of its importance, delegation is an element included in many management training courses, particularly ones such as general management training or project management. Whilst the theory can be taught, it is only through practice and experience that a manager can trust those around them to carry out tasks to a sufficient standard and relieve some of the burden from the manager's shoulders.