DAX built quotes, cash plans and invoices from one controlled workbook engine. Change a value below to inspect how the delivered formulas recalculate every dependent result.
Inspect DAX's quote, cash-plan and invoice views. Change a quantity, rate or cost to trace the recalculation through the finished system.
—
A workbook is software, so we treat it like software. Inputs live in one place and are the only cells you touch. Calculations are formulas, never numbers typed over formulas. Every rate, tax percentage and threshold sits in a named assumptions block, so changing the tax rate is one edit and not forty. Validation stops bad input at the cell instead of poisoning the totals three tabs later. And you get the map — which cell feeds what — because a file nobody can maintain is a file you'll pay to rebuild.
Three scopes. Each one ships a workbook that calculates on its own, refuses bad input, and comes with the notes to keep it alive after handover.
Four failure modes anyone who has commissioned spreadsheet work will recognise — and how this studio is built so they don't happen.
"It worked on their machine. I added three rows and half the totals stopped counting them."
Ranges are built to grow. Totals reference whole structured ranges or tables rather than a lucky selection of eight cells, so a new row lands inside the sum instead of outside it. Before delivery, we add rows, delete rows, and paste a block in the middle — if a total flinches, it isn't finished.
"The tax rate was typed straight into forty formulas. When it changed, the whole file had to be redone."
Constants live in one assumptions block and nowhere else. Rates, thresholds, discounts and fees are cells you can point at, and every formula reads them. Change the number once and the file agrees with itself. You'll notice the demo above does exactly this — the tax line reads a rate, it doesn't contain one.
"Someone typed 'N/A' into a number column and the whole model quietly returned garbage for a month."
Input cells get real validation: number-only, list-only, date ranges, minimums. Bad entries are refused at the cell with a message that says what's allowed. Where a value can legitimately go missing, the formula handles the blank on purpose instead of pretending it's a zero. Try typing a word into a number column in the rig above — it flags immediately.
"The macro died on my colleague's Excel, and there was no documentation to work out why."
We ask what your team actually runs — Excel on Windows, Excel on Mac, Google Sheets, or all three — and build for that before writing a line of code. Most jobs don't need a macro at all, and we say so. When automation is genuinely the right answer, it ships with documentation, a plain-formula fallback, and a walkthrough recording so the file survives the person who commissioned it.
Free look at what you have now, a fixed quote, and a working sheet before you pay the balance.