Lean Accounting
Interactive Toolkit
Built for operations and finance professionals — not just accountants. Simulate how lean improvements are reported differently, build a live box score, and audit your own processes.
Based on Practical Lean Accounting by Maskell & Baggaley, and the BMA Lean Accounting course by Nick Katko.
Traditional vs Lean Simulation
See why standard costing can penalise lean improvements — with real numbers.
Module 1Box Score Builder
Build your value stream box score. Compare current vs future state. Answer the 6 key questions.
Module 2Performance Measurement Linkage
Explore how daily cell metrics connect all the way up to strategic financial outcomes.
Module 3Accounting Waste Audit
Identify the 8 wastes in your accounting processes. Get a score and practical next steps.
Module 4Traditional accounting systems were designed for mass production. When lean companies keep using them, the numbers can make lean improvements look bad. This toolkit helps you see through that — and understand the lean accounting alternative. Content is grounded in Practical Lean Accounting (Maskell & Baggaley, 2nd Ed.) and the BMA course by Nick Katko.
BMA Lean Accounting
Certification Courses
This toolkit is grounded in BMA's lean accounting framework — created by Brian Maskell and taught by Nick Katko. If you want to earn a formal certification directly from the source, BMA offers two self-paced online courses with CPA continuing education credits.
Lean Management Accounting Certification
- The Lean Management Accounting System
- The Lean Performance Measurement System
- Measuring Capacity
- Value Stream Income Statements
- Using a Box Score
Lean Accounting Process Improvement Certification
- Lean Thinking for Accounting
- The Daily Lean Management System
- Improving Accounts Payable
- Improving Accounts Receivable
- Improving Month-End Close & Budgeting
Online, self-paced. 5 classes per course (~1.5–2 hrs each). Certificate issued on completion. Group discount applies to 3+ people from the same company.
Traditional vs Lean Accounting Simulation
Traditional standard costing was designed for mass production. When lean companies use it, the numbers tell the wrong story. This simulation shows you exactly how — and why it matters.
Choose a scenario, then adjust the parameters to see how traditional and lean accounting report the same improvement differently.
When you reduce inventory under standard costing, fewer overhead costs get absorbed into inventory. Those costs hit the income statement — making profit look like it dropped. Lean accounting shows the truth: you released real cash and the business improved.
This exact scenario is described in Chapter 1 of Practical Lean Accounting: a company reduced inventory and saw their standard cost go up, so they cancelled the lean cell — the wrong decision, caused by misleading information. The BMA course by Nick Katko refers to this as the fundamental conflict between standard costing assumptions and lean thinking.
Before Lean
After Lean
Traditional P&L shows no financial improvement even though you eliminated waste and freed capacity. The lean box score makes the capacity gain visible — it's the bridge to financial improvement. When freed capacity is used to grow sales or reduce resources, the financial results follow.
The book explains: "Changes in capacity usage are the bridge between operational and financial change." This is why the box score has three sections — operational, capacity, and financial — not just a P&L.
Smaller batches mean the same fixed setup cost spreads over fewer units, so standard cost goes up — even though lean batch reduction is operationally better in every way: faster flow, less WIP, shorter lead times. This is exactly why companies abandon lean improvements.
Value stream costing doesn't calculate per-unit overhead allocations at all. It tracks total value stream costs against total value stream revenue — which is what actually matters for decisions.
Standard costing is built on assumptions valid for mass production — specifically that maximum utilisation and large batches are good. Lean violates every one of those assumptions. The result: standard costing motivates non-lean behaviour. Value stream costing is the lean alternative — simple, direct, and aligned with how lean actually works.
Box Score Builder
The box score is the core lean management accounting tool. It shows operational performance, capacity, and financials in one view — and lets you project the future state. Enter your numbers and explore the 6 structured questions.
Available = 100% − Productive − Non-Productive.
Performance Measurement Linkage Chart
Every daily metric on the shop floor connects to a strategic financial outcome. This chart shows how — and why lean organisations measure at three levels: strategic/monthly, value stream/weekly, and cell/daily.
Click any metric to see what it means, how it's calculated, and how it connects to financial performance. The three columns represent three different measurement cadences — each level feeding the one above it.
Traditional accounting reports monthly. But lean problems can compound within hours. By measuring at three cadences — daily at the cell, weekly at the value stream, monthly at the strategic level — teams can see and fix problems before they become financial losses.
From Practical Lean Accounting: measurement must shift from a historical, results-only orientation to identifying the drivers of performance beforehand and measuring those. It is the difference between looking in the rear-view mirror and watching the road ahead.
Accounting Process Waste Audit
Lean thinking applies to the accounting function itself. The 8 wastes exist in every accounting and finance process. Check which ones exist in your organisation and get a waste score.
Based on the BMA course by Nick Katko and Practical Lean Accounting: traditional systems are wasteful — they require huge amounts of unnecessary work, gathering and analysing data, producing unhelpful reports, and generating additional non-value-adding tasks. Check the wastes that exist in your function.
Lean accounting means applying lean thinking to the accounting function itself. The goal: eliminate waste, then use freed-up capacity for higher-value financial analysis and decision support.