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.
â  Variable manufacturing overhead. â  Fixed manufacturing overhead. â  Under absorption costing, the following costs are treated as period expenses and are excluded from. product costs: â  Variable selling and administrative costs. â  Fixed selling and administrative costs.