Which principle of management envisages that each group of activities having the same objective

Which principle of management envisages that each group of activities having the same objective, must have one head and one plan? Explain the principle with suitable example.

‘Unity of direction’ is the principle of management which states that each group of activities having same objective must have one head and one plan.
For example, if an organisation is producing different types of toys plastic toys, soft toys, then each type of toys should have separate division and under each division, there should be a boss who looks after the work of that division and employees should work under him towards the attainment of plan of their division under the direction of one head only.