Why is planning an all-pervasive function of management?

Since the job of planning is performed by the managers at different levels working in the enterprise, it is appropriate to call it all pervasive. Planning is an important function of every manager, he may be a managing director of the organisation or a foreman in a factory. The time spent by the higher level managers in the process of planning is comparatively more than the time spent by the middle-level and lower-level managers. It is, therefore, clear that all the managers working in an enterprise have to plan their activities.