The spreadsheet that runs everything

Nobody decides it. Someone builds a sheet to track quotes. It gets a second tab for orders. A lookup to the price list. A macro to produce the invoice. A shared drive so the office can use it. Ten years on, it has forty tabs, twelve thousand rows, formulas that reach across sheets in ways nobody can follow, and a copy on every laptop that has drifted from the one on the server.

That's not a failure of anyone. Excel is the best tool in the world for a person who knows what they need and needs it today. The trouble is that it was never a system, and the business started treating it as one.

• Two people can't work in it at once, or one of them loses their changes when they can.
• There are several copies, and they disagree.
• It's slow to open, slow to recalculate, and corrupts now and then.
• The macros were written by someone who has left, and nobody dares press the button they don't understand.
• Numbers get retyped from it into another system, and the two never quite match.
• There's no history: a cell was changed last Tuesday, and nobody knows what it said before.
• The auditors, the bank or a customer have asked how the business controls it, and the answer was a shrug.

Everything a new system needs, in a form that's easier to read than most code.

• The data model. Every column is a field. Every tab is a table, or a process. The lookups are the relationships.
• The rules. Every formula is a business rule written down. The pricing calculation, the VAT handling, the discount that applies to one customer type, the date maths that decides what's overdue.
• The processes. The macros, and the manual steps around them, describe what the business does in what order.
• The data. Years of it, ready to migrate.

Reading a spreadsheet as a specification is most of the work, and it's work that has to be done by a person sitting with the person who built it.

A database the business owns, with the rules in one place and enforced, and screens designed from the processes rather than copied from the grid. Multiple people at once, a history of every change, one version of the truth, and reports that come out of the data instead of being assembled by hand.

Excel doesn't disappear. It stays for what it's good at: ad-hoc analysis, what-if, the finance director's own models, and it reads from the new system's data instead of being the place the data lives. That distinction, the system as the record and Excel as the lens, is the one that makes the change stick.

1. Read it. The assessment sits with the person who built the spreadsheet and maps every tab, column, formula and macro into a system description with the rules made explicit. Where two copies disagree, the differences are listed rather than guessed.
2. Migrate the data, cleaned. Duplicates resolved, free-text columns turned into proper values, dates stored as text made into dates. Reconciled against the spreadsheet's totals.
3. Build the first process, the one that hurts most: usually the one where two people collide or where numbers get retyped. Run it in staging on the migrated data, checked by the people who use it, then live. The spreadsheet keeps running everything else.
4. Repeat, process by process, until the spreadsheet is a report rather than a record.
5. Point Excel at the system for the analysis people still want to do there.

Each stage is priced before you commit; stop after any stage and keep everything.

It comes out of the spreadsheet once, cleaned, and it never meets a change until the change has proven itself somewhere else. The migration is tested on a copy in a test environment, then run in staging with every total reconciled against the spreadsheet, before anything connects to live. The spreadsheet stays as the fallback until you're confident.

The assessment is from £395 + VAT, sized on a free one-hour consultation, with an exact price before you commit. For a spreadsheet system it maps the tabs, formulas and macros, tests how the data comes out, and prices the first process as a fixed number. Spreadsheet systems are often small in scope and quick to improve, which makes them a good first project. What drives the price and the payment terms each have a page.

The spreadsheet is the specification and the person who built it is the expert. Marc Allington has turned enough spreadsheets into systems to know that the formulas are worth more than they look and the macros less. Everything we build runs on open, widely used technology, in your own accounts, with full source code and ownership transferring to you on final payment.