The Budget Impact Model Developer reads a specification and builds an Excel workbook from it, with every input visible and every change checked as you make it. A spreadsheet model is easy to read if you know where to look. Finding the input, and every formula that uses it, is where the hours go. The film uses a test specification with invented products and illustrative values.
You upload the specification and choose Analyze. The module reads the document once, with six questions: population, market, costs, events, settings, and the results the document states.
Every figure the document states goes into one table. Each row shows what the input is, what it is tied to and the document's own sentence, and a row opens for the reason and the sensitivity setting.
The Results tab checks the model against the figures the document prints, and the comparison lists each one.
When you change a value, the check responds and reports which stated results no longer reproduce, with the reason.
Where the document gives a range, you can change it too. Inputs in the same group move together.
The chat answers questions about the model and cites the sections of the specification.
Asked to change a price, it declines and links to the inputs table. The chat explains the model, and changes stay with you.
When the inputs are settled, one click compiles the workbook. After the build, each input shows where it sits in the workbook, and a changed value rebuilds the workbook.
The download menu offers the workbook, the sensitivity macro, and a session record with the specification, answers, notes and results.
The workbook is an ordinary Excel file. A cell on the market shares sheet points to a named input, the engine sheet builds on that input, and the results sheet reads the engine. Each link is a formula you can click.
The Parameters Master sheet lists every input with an override column and the sensitivity columns. The sensitivity control sheet holds the analysis settings.