I built this to show what a margin analysis actually produces.

"Sales are up and profit isn't" is the most common version of the question, and the answer is usually counterintuitive — so it's a better demonstration than something where the finding is obvious. On this order book the leak turned out to be at the top, not the bottom: orders over £2,500 are 75% of revenue at the worst margin on the book, while orders under £250 beat the book average.

The order book is generated and the generator is published with it, so every figure reproduces from scratch. That's deliberate. An analysis of a real company's numbers can't be checked by anyone reading it.