▪ 5. Behaviour: fixed, variable, semi-variable and stepped fixed

Cost behaviour is the way in which costs are affected by changes in output.

成本性态，也叫成本习性，指成本对业务量（产量，销售量或机器小时数等）的依存关系。

Management decisions will often be based on how costs and revenues vary at different activity levels.

Cost behavior patterns: fixed, variable, semi-variable and stepped fixed, others.

5.1 Fixed cost (固定成本)are costs that are not affected in total by the level of activity, but remain the same for a particular period of time.

Example: rent of building, salary of a directors, annual property insurance, depreciation of a single machine, etc.

5.2 Variable cost (变动成本)are the costs that change in total in direct proportion to the level of activity. Cost per unit remains the same for each unit produced.

Example: direct materials, direct labor and sale commission.