What are the factors that affect the classification of a cost as direct or indirect?

Several factors affect whether a cost is classified as direct or indirect:
The materiality of the cost in question. The smaller the amount of a cost–that is, the more immaterial the cost is–the less likely it is economically feasible to trace it to a particular cost object.
Available information-gathering technology. Improvements in information-gathering technology make it possible to consider more and more costs as direct costs.
Design of operations. Classifying a cost as direct is easier if a company's facility (or some part of it) is used exclusively for a specific cost object, such as a specific product or a particular customer.

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