The problem considered here is that of managing and controlling the industrial system to achieve efficient performance. Emphasis is placed on structuring the decision making and control functions, taking into account the fact that the production process runs continuously with no starting or end point, and undergoes major changes in product specifications, quality requirements, equipment characteristics, resource availability, and the like. Since all these changes are time functions, the time factor plays a very important role in decision making and control and in functional structuring. 

It is shown that the functional structure is a multilevel hierarchical mode with horizontal and vertical decomposition planes. The vertical planes represent temporal decomposition, reflecting the subordination of decision making and control for each time duration or time horizon. The horizontal planes form layers related to each time horizon and consist of the set of decomposed subproblems to be solved in coordinated mode. 

The philosophy of this functional hierarchical structure is discussed and some motivation for time horizon estimation is given.