Since a leader is a human, No leader can complete all tasks with accuracy alone maintaining the leadership on one hand. Nevertheless, It is not possible to complete all the tasks by one person. For this reason, To achieve organizational goals, which tasks should be done those are divided among other qualified and experienced persons of organization. Although all members of a team work together, but the success and the failure both goes to on the behalf of the leader.
To achieve goals, A leader can delegate some of his tasks on other experienced and qualified persons. But the leader must be careful all the time about those delegated tasks i.e. Are those being completed successfully or not. On other side, The leader should be careful to choose the right person for delegation of authority. Because, If the person turns into failure, the responsibility will come on the head of the leader.
Here, One thing should be clear. Delegation of Authority does not mean "Transfer of all tasks and responsibilities on other shoulders". A leader can't give more freedom to his subordinates which he gets from his superior. Furthermore, the amount of delegated tasks must taken as completed from subordinates with maintaining the timeliness and accuracy by the leader.
Delegation of authority may work as opposite direction for a organization. A responsible leader must keep his cautioned eyes on this matter. And all the process is stated as the delegation of authority and responsibility of a leader. Because for the success and failure of such kind of delegation the leader is only responsible.