Collapse of earth into underground mines, or subsidence, is a serious problem. In room-and-pillar and long-wall mines, columns of coal and other structures are used to support the ground above. Later in the mining process, they are often taken out. The mines are left to collapse.
We view overhead as two types of costs and define them as follows: Manufacturing overhead (also referred to as factory overhead, factory burden, and manufacturing support costs) refers to indirect factory-related costs that are incurred when a product is manufactured.
Overhead expensesâalso called indirect manufacturing costs and factory overheadâencompass three general kinds of costs: those for indirect materials, indirect labor, and all other miscellaneous production expenses such as taxes, insurance, depreciation, supplies, utilities, and repairs.