An activity cost driver is anything that causes a company’s variable costs to either reduce or grow. Since measuring an activity cost driver is a way to streamline the administration of managing production costs, it’s an integral part of activity-based costing.

Examples of activity-cost drivers are warehouse expenses, modifying engineering designs, and retooling, setup, and maintenance costs for machining needs. This can include higher warehouse expenses due to increased rents or leases, which add to the final amount of the product or service’s sales price. Machining costs include initial setups for initial production and ongoing maintenance costs for continued runs. If production needs to be re-engineered to different production parameters, those professional revision costs need to be added to the ultimate product or service cost calculations.

These cost drivers are used as a starting point to project the business’ operational and profitability goals through the use of activity-based costing (ABC), a type of managerial accounting.

ABC accounting is a way to determine the expenses of each output by looking at the inputs used during the company’s operations, be it power for the machinery, Information Technology (IT) needs, or labor.

It’s important to know that one variable expense can impact multiple single activity cost drivers. For example, wage costs and machining expenses can be identified as activity cost drivers in connection with production. The first step is looking at how ABC accounting can determine indirect costs.

Activity-Based Costing Illustration

A business wants to look at how its production space and its lease or real estate and property tax costs are attributable to individual widgets or services, based on the percentage dedicated to the respective product or service. If it’s not allocated properly, determining sales prices and profitability can be negatively impacted.

If a company has two product lines with the same retail prices and production quotas, with direct costs of $700 and $250, it’s important to see how the production area for each product impacts the company’s overall operations. If the first item uses 40 percent of the production area and the second item uses 60 percent of the production area, and the rent is $1,500, the rent needs to be factored in. The first item would see an additional cost of $600 plus the original $700, or a total of $1,300. The second item’s cost would be $900 for the rent and $250 for the item, or a total of $1,150. While the initial direct cost for the first item seems higher than the second item, when factoring in all costs, this time it’s still true – but that’s not always the case.

Once this has been established, and then a company receives a new order, the following illustrates how measuring an activity cost driver, such as performing maintenance on machines after a production run, will cost the company to have it ready for their next order. If it costs a company $200 for machine maintenance and it produces 1,000 widgets, a $0.20/widget cost would be factored into margins and retail pricing.

While this provides an overview of how activity cost drivers work, it is part of a comprehensive approach to how businesses measure their margins and ultimately profitability.