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Which Excel files belong in a system?

  • Excel
  • Supplementary master data

Grunddata team

Excel is where most business data starts, and for good reason. It is fast, flexible and everyone knows how to use it. The problem is not Excel. The problem is when a file quietly turns into a system that nobody designed.

Excel is still the right tool for a lot of work

Section titled “Excel is still the right tool for a lot of work”

Personal analysis. One-off calculations. Drafts and models you are still shaping. Files only you use. None of these need a system, and moving them into one would slow you down.

The question is not whether to use Excel. It is which files have taken on a job Excel was never built for.

Four signs a file has outgrown Excel

Section titled “Four signs a file has outgrown Excel”

1. Several people edit it. Once more than one person changes the same file, you need to know which version is current and who changed what. Excel was not built to answer that.

2. Other files, reports or systems read from it. When a file feeds something else, a change in it travels further than the person making it can see. A moved column can break a report in another department.

3. Someone needs to know who changed what, and when. If an auditor, a manager or a regulator could ask how a value came about, the file needs a history. Excel keeps the current state, not the story of how it got there.

4. An error in it ends up in a report that matters. If a mistake in the file would reach management, auditors or a regulator, the file deserves the same controls as the systems around it.

One sign is a reason to watch the file. Two or more, and it belongs in a system.

What it looks like when it goes wrong

Section titled “What it looks like when it goes wrong”

At one organisation we spoke to, a junior analyst moved three cells in a large shared file. Nobody noticed when it happened, and there was no way to roll the file back. Nothing about this is unusual. It is what happens when a file that many people depend on has no validation and no history.

What regulators say about spreadsheets

Section titled “What regulators say about spreadsheets”

Regulators do not ban spreadsheets, but they expect them to be controlled.

BCBS 239, the Basel Committee’s principles for risk data aggregation, says that risk data should be aggregated on a largely automated basis. Where a bank relies on manual processes and desktop applications such as spreadsheets, it should have effective mitigants in place, for example end-user computing policies and procedures.

In February 2026, Finansinspektionen published a review of how 33 Swedish banks and credit market companies manage operational risk. It noted that several firms with system support for that work use solutions built in Microsoft tools such as Excel, SharePoint, Forms or Lists, and that seven firms said they have no system support at all.

A system does not have to mean leaving Excel

Section titled “A system does not have to mean leaving Excel”

Moving a file into a system does not have to mean a large IT project or teaching people a new tool. What needs to change is where the data lives and how it is controlled:

  • The data is stored outside the file, in one place.
  • The table has an owner and rules for what is allowed.
  • Every change is checked before it is saved.
  • Every change is recorded with who, what and when.
  • Other files, reports and systems read from the same place.

The people who maintain the data can keep working in Excel. Excel becomes the interface, not the storage.

Where Grunddata fits

Section titled “Where Grunddata fits”

Grunddata is built for exactly these files. The team keeps working in Excel through an add-in and publishes changes, one row or in bulk. Each change is validated against the rules of the table and recorded with author, timestamp and message. Reports, other files and the data warehouse read the same data through API and OData. It is the same Excel, with a system behind it.

Where to start

Section titled “Where to start”

Go through the shared drive and pick out the files that show two or more of the signs above. Start with the one that feeds the most reports. Move that one first, keep the team in Excel, and see what changes.

Get in touch if you want help picking the first file.

Sources

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