We have introduced two major classifications of costs: direct/indirect and variable/fixed. Costs may simultaneously be as follows:
Exhibit 2-5 shows examples of costs in each of these four cost classifications for the Tesla Model 3.

The vertical line traces the cost-behavior pattern and the horizontal line traces the assignment of costs to cost object.
The details of the assignment of costs to cost object for the two types of cost-behavior pattern are as follows:
Cost-behavior pattern: Variable costs
Assignment of costs to cost object: Direct costs
Cost object: Tesla Model 3s produced. Example: Tires used in assembly of automobile.
Assignment of costs to cost object: Indirect costs
Cost object: Tesla Model 3s produced. Example: Power costs at the Tesla factory. Power usage is metered only to the plant, where multiple products are assembled.
Cost-behavior pattern: Fixed Costs
Assignment of costs to cost object: Direct costs
Cost object: Tesla Model 3s produced. Example: Salary of supervisor on Tesla Model 3 assembly line.
Assignment of costs to cost object: Indirect costs
Cost object: Tesla Model 3s produced. Example: Annual depreciation costs for the Tesla Factory in Fremont. Depreciation costs are for the whole plant, where multiple products are produced.