TDABC explained: the practical guide for business leaders

If you run a business and suspect your product or service costs don’t reflect reality, you’re not alone. Most companies use traditional costing methods that spread overhead evenly, as if all products, clients, and services consumed resources the same way. The result? Products that appear profitable may be losing money, and clients that seem small may be your most lucrative.

TDABC (Time-Driven Activity-Based Costing) solves this problem. In this guide, we explain how it works, why it’s superior to traditional methods, and how your business can implement it practically.

What is TDABC?

TDABC is a cost management methodology developed by Robert Kaplan and Steven Anderson that calculates the true cost of every product, service, or client. Instead of using averages or arbitrary percentages to distribute overhead, TDABC measures two simple parameters: the cost per minute of capacity supplied by each department, and the actual time each activity takes.

Why traditional costing fails

Traditional costing was designed for a simpler industrial era when overhead was 10-15% of total costs. Today it reaches 40-60%. Allocating these costs using machine hours, production volume, or revenue percentages creates massive distortions: low-volume products get under-costed, complex clients get cross-subsidized by simple ones, and unused capacity hides in allocations. The typical finding? When a company implements TDABC, it discovers that 20-40% of its products or clients are actually unprofitable.

TDABC vs ABC: what’s the difference?

ABC was an important advance in the 1990s but proved expensive to implement, difficult to maintain, and frequently abandoned within 2-3 years. TDABC solves these problems: 2-4 month implementation (vs 6-12 for ABC), simple incremental maintenance, improving accuracy over time, and scalability to millions of transactions.

How TDABC works in practice

Implementation follows six steps: identify resource groups, calculate capacity cost rates, build time equations, assign costs to objects, analyze profitability through the Whale Curve, and take strategic action on repricing, restructuring, and optimization.

Next step: free assessment