1) Business economic 
A cost object is a term used primarily in cost accounting to describe something to which costs are assigned. Common examples of cost objects are: product lines, geographic territories, customers, departments or anything else for which management would like to quantify cost. The use of cost objects is very common with activity based costing systems...
A cost object is a managerial term for a product, process, department, or customer that costs originate from or are associated with. In other words, it?s something that costs can be identified with and traced back to.