data modelling blog

Deliverable Management Information Systems

Why did substantive changes to the MS Excel spreadsheet end 20 years ago? Not even a simple tweak to the LOOKUP function to allow exact-match with a FALSE argument? That on its own would unify a batch of sub-optimal approaches available through all the alternatives, with INDEX/MATCH combinations...

Charting new territories with FAST

In my experience making a good model requires you to spend time not modelling, but talking about it instead. With my immediate team, I can talk in front of the monitor with the model on it. But other project members do not talk in columns and rows; they prefer to talk with pictures. Pictures mean...
Average Internal Rate of Return

Average Internal Rate of Return (AIRR)

An introduction by F1F9: We were approached by Thierry Renard and Carlo Alberto Magni and were intrigued by what they had to say: a new approach to calculating an internal rate of return. What's more, they were illustrating the application of the Average Internal Rate of Return ("AIRR") using Excel...
Modelling Balances

How to Model Balances in Excel

There are two basic types of line item in financial models – flows and balances. Balances are amounts at a point in time. Balances can be financial or non financial. Every balance has similar properties. This blog explains what those properties are, and gives a standard model component that...