Cost-Accounting Activity-Based-Costing-Advanced TimeDriven ActivityBased Costing TDABC Capacity Cost Rate

? What this actually is

Time-Driven Activity-Based Costing (TDABC) is a costing method that assigns costs to products, services, or customers based on the time spent on activities and the cost of supplying capacity for those activities. It matters because it provides a more accurate way to allocate overhead costs, especially in complex environments where traditional costing methods fall short. The core idea is to calculate a Capacity Cost Rate for each activity, which is then used to allocate costs.

? The core logic (or formula)

1. Identify Activities: Determine the key activities involved in producing a product or service.
2. Estimate Practical Capacity: Calculate the practical capacity of resources used in these activities.
3. Calculate Cost of Supplying Capacity: Determine the total cost of supplying the capacity for each activity.
4. Compute Capacity Cost Rate:
5. Formula: Capacity Cost Rate = Cost of Supplying Capacity / Practical Capacity
6. Allocate Costs: Use the Capacity Cost Rate to allocate costs based on the time spent on each activity.

? Hidden rule nobody explains

In practice, the practical capacity is often less than the theoretical capacity due to factors like breaks, maintenance, and downtime. Always use practical capacity for more accurate costing.

? Practical example / breakdown

Let's say a company has an activity called "Machine Operation" with the following details: - Practical Capacity: 2,000 hours per year (considering breaks and maintenance) - Cost of Supplying Capacity: $100,000 per year (including depreciation, labor, and overhead)

Step-by-Step Calculation: 1. Identify Activity: Machine Operation 2. Estimate Practical Capacity: 2,000 hours 3. Calculate Cost of Supplying Capacity: $100,000 4. Compute Capacity Cost Rate:
- Capacity Cost Rate = $100,000 / 2,000 hours = $50 per hour 5. Allocate Costs: If a product uses 10 hours of machine operation, the allocated cost is:
- Allocated Cost = 10 hours * $50/hour = $500

? Your move today

Goal: Calculate the Capacity Cost Rate for a specific activity in your organization or a case study.

Step-by-Step: 1. Choose an activity (e.g., Customer Service).
2. Estimate the practical capacity (e.g., 1,500 hours per year).
3. Determine the cost of supplying capacity (e.g., $75,000 per year).
4. Calculate the Capacity Cost Rate using the formula.
5. Save your calculation in a document or spreadsheet.

What to save: A completed calculation with the activity name, practical capacity, cost of supplying capacity, and Capacity Cost Rate.

? Quick reference asset

⚠️ Common mistakes & recovery

• Common Error 1: Using theoretical capacity instead of practical capacity.
• Recovery: Always adjust for realistic working conditions.
• Common Error 2: Overlooking indirect costs in the cost of supplying capacity.
• Recovery: Ensure all relevant costs are included.
• Quick Check: Verify that the Capacity Cost Rate makes sense by comparing it to similar activities.
• Exam Tip: Practice with realistic scenarios to understand the nuances of practical capacity and cost allocation.

✅ Completion check

"I can calculate the Capacity Cost Rate for an activity and use it to allocate costs accurately."