Activity-based budgeting
Definition, purpose, and time frame
While ABC is primarily used as a tool for overhead allocation by linking costs to activities, ABB extends this approach to forecast future resource needs - essentially running ABC’s logic forward: instead of tracing costs backward from finished products to the activities that caused them, ABB starts from budgeted output and activity levels and works forward to the resources those activities will require. This aligns budgets more closely with activity levels and improves cost precision. Because the budget is built up from projected activity levels rather than adjusted from a prior period’s totals, ABB’s output can differ noticeably from a traditional budget whenever expected activity volume changes from year to year. If the company is using ABC, then ABB is the most logical way of preparing relevant budgets.
ABB typically operates within an annual time frame, though it is flexible enough to apply to project-specific or departmental budgets. It is most effective in industries where overhead costs fluctuate based on activity levels, such as manufacturing, project-driven organizations, and service industries.
Components and interrelationships
ABB involves key components:
- Activities: All necessary actions that drive the production or service process, such as machine setups, quality checks, and customer service.
- Cost drivers: Elements that drive costs for each activity, such as machine hours, labor hours, or units produced.
- Resource costs: Total costs associated with each activity, calculated based on the level of resources each activity requires.
In ABB, activities and cost drivers are closely analyzed to allocate resources to activities that drive costs. For example, machine hours may drive maintenance costs, while labor hours are key for assembly processes. Cost drivers link resource consumption directly to each activity, clarifying where resources will be consumed in the budget.
Developing the activity-based budget
The development of an activity-based budget involves several structured steps to ensure that budget allocations are both accurate and activity-based:
- Identify activities: Begin by identifying all necessary activities required to achieve production or service goals.
- Determine activity cost drivers: Identify the primary drivers that create costs in each activity, such as machine hours, labor hours, or setup frequency, which will influence resource needs.
- Estimate budgeted levels of activity: Forecast the expected level of each cost-driving activity, considering the budgeted production level. This step links production output to the activities needed, establishing a foundation for allocating overhead costs.
- Develop budgeted cost pools: Create budgeted cost pools for each activity based on projected overhead costs. Cost pools represent the total budgeted overhead for each activity, allowing for focused resource allocation.
- Calculate budgeted costs per unit of activity: Determine the budgeted overhead cost per unit of activity by dividing the total budgeted overhead cost for each activity by the total budgeted activity units. For example, if total budgeted maintenance costs are $50,000 and the activity level is 5,000 machine hours, the budgeted cost per machine hour would be $10.
- Allocate overhead to products: Using the budgeted cost per activity unit, allocate overhead costs to each product based on its level of each activity. For instance, if a product requires 100 machine hours, it would receive $1,000 in maintenance costs (100 hours × $10 per machine hour). Different overhead costs, each with its own cost driver, are allocated based on the activity usage for each product.
Example: Activity-based budget
Anchor Manufacturing budgets two cost-driving activities for the coming year: machine setups and quality inspections.
- Setups: 200 setups budgeted at $400 per setup
- Inspections: 500 inspections budgeted at $20 per inspection
The budgeted overhead for each activity is:
Now suppose Anchor shifts to smaller batch sizes for the same total output, which raises the number of setups from 200 to 260 while inspections stay at 500. The setup budget increases by:
Even though total units produced haven’t changed, the overhead budget rises to $80,000 + $24,000 + $10,000 = $114,000. A traditional budget built from last year’s total or from units produced wouldn’t capture this increase, because it isn’t driven by the activity that actually changed - the number of setups.
Answer: Total budgeted overhead is $90,000 initially, rising to $114,000 after the increase in setups.
When a company uses ABC to allocate overhead costs, integrating ABB into the budgeting process enhances accuracy and responsiveness to changes in activity levels, ensuring budgets are more closely aligned with real production demands.
Benefits and limitations
Benefits
- Improved cost precision: ABB enhances accuracy by focusing on projected activity levels, reducing the likelihood of over- or underestimating resource requirements.
- Better resource allocation: By directing resources to specific activities, ABB promotes cost-efficient operations, especially in areas with high resource demands.
- Alignment with cost drivers: ABB links budgets to activity cost drivers, enabling managers to control activities that drive costs, which can lead to targeted cost reductions.
- Identification of budgetary slack: ABB’s detailed approach highlights areas where budgets may be overstated, helping to identify and reduce budgetary slack for more realistic budget targets.
Limitations
- Complexity and time demands: ABB requires detailed identification of activities and cost drivers, which is more time-consuming than traditional budgeting methods.
- Data dependency: Accurate data on activity levels and resource usage is essential for ABB, as data inconsistencies can impact budget accuracy.
- Dependence on ABC: ABB relies on the organization using an activity-based costing system, since it allocates costs based on ABC principles; it’s easiest to implement well when a company already has an ABC system in place.