Excel as a Database? When Spreadsheets Become a Risk

Excel as a Database: the Most Widespread Legacy System in the Mid-Market

When we ask companies about their most important IT system, very few name Excel. Look closer, however, and quotation costing, workforce planning, inventory lists, and monthly reporting surprisingly often run in spreadsheets that were set up "just for now" years ago. That makes Excel the most widespread legacy system in the mid-market – not because the software is bad, but because it has taken on tasks it was never designed for.

This development has a name: shadow IT. Departments build themselves working island solutions that initially save time and that later nobody wants to replace because "everything depends on them." Just as with a grown Access database, a system emerges over the years that is business-critical but runs outside any IT responsibility – without a permissions concept, without version control, without a backup strategy.

So the question is not whether Excel is a good tool. It is, and it will remain one. The question is: where in your organization is Excel being used as a database, a business application, or a process engine – and what is that costing you by now?

How to Tell That Excel Has Become a Risk

From our projects we know recurring warning signs that reliably indicate a spreadsheet has outgrown its limits:

• Several people work on one file. At the latest when file names like Costing_final_v7_NEW.xlsx circulate, no reliable data basis exists anymore. Who changed what and when can no longer be traced.
• Formulas nobody understands anymore. Research on spreadsheet quality has come to the same conclusion for years: the vast majority of larger workbooks contain errors – Raymond Panko's much-cited research puts the share of faulty spreadsheets at around 90 percent [1]. In a costing sheet that determines quotes or wages, that is not a cosmetic flaw.
• The file hits hard limits. Excel ends at 1,048,576 rows [2] – and older formats much earlier. How real this limit is was demonstrated by the UK health authority, which lost nearly 16,000 Covid cases in 2020 because an import exceeded the row limit of an old Excel file format [3].
• Personal data travels by e-mail. As soon as spreadsheets containing employee or customer data circulate through the company as attachments, you lose control over copies and access – a problem that becomes visible at the latest during a data protection audit.
• Only one person knows the file. When the colleague who "built the Excel" leaves the company, the knowledge leaves with them. This single-person dependency is the same pattern we know from grown legacy systems – just without documentation.

The collection of the European Spreadsheet Risks Interest Group has documented for years what real damage arises from such constellations – from million-euro losses to faulty tenders [4]. The more of these warning signs you recognize, the more urgent a structured look at your spreadsheet landscape becomes.

Where does your Excel landscape stand? We give you an honest overview in a short time of which spreadsheets can stay and where action is needed – as part of our service Renewing old systems or directly via a process automation analysis. The fastest way is a direct conversation: book a 30-minute intro call.

Replace or Connect? Two Ways Out of the Excel Chaos

The most important insight from our project practice: not every spreadsheet has to go. Anyone who flatly proclaims "abolish Excel" loses the departments and replaces working tools with software nobody uses. It is more sensible to differentiate by the role a spreadsheet plays:

| Role of the spreadsheet | Typical examples | Recommendation | |---|---|---| | Personal working tool | Ad-hoc analyses, individual evaluations | Keep – that is what Excel is made for | | Data hub between systems | Export from ERP, manual transfer into the next tool | Connect – interface instead of copy-paste | | De-facto business application | Workforce planning, costing, inventory management with macros | Replace – database or web application | | Reporting | Monthly reports from several sources | Automate – data flows, the report builds itself |

The path of connecting is frequently overlooked: many Excel problems do not arise in the spreadsheet itself but in the manual transfer of data between systems. An interface that automatically brings orders, master data, or key figures to where they are needed eliminates transfer errors without changing the familiar environment for users. This is often the fastest first step – and it builds trust for the bigger ones.

The path of replacing pays off where Excel has become a business application. A central database with a lean web interface brings exactly the properties spreadsheets lack: simultaneous work without version chaos, clear access rights, traceable changes, and data validation right at input. Which technology stands behind it – a SQL server, a cloud database, or a low-code platform – is decided by the specific case, not by trends.

Making the Transition Step by Step

The biggest mistake in Excel replacements is the attempt to replace everything at once. We recommend a four-step approach that has proven itself in practice and mirrors the pattern used to replace a classic legacy system:

1. Inventory: Which spreadsheets exist, who uses them, which decisions depend on them? This overview alone is an eye-opener for many management teams – the number of business-critical files is almost always higher than assumed.
2. Prioritization by risk: First in line are the spreadsheets containing personal data, used by several people, or driving financial decisions. The personal working tool of a single specialist may stay.
3. Clean the data, then migrate: Spreadsheets grown over years contain duplicates, inconsistencies, and dead records. Anyone transferring them unchecked into a new system digitizes their chaos. Cleaning before migration is therefore not an annoying intermediate step but the actual gain in value.
4. Parallel operation instead of a cut-off date: The new solution runs alongside the old spreadsheet for a while. Users compare results, report gaps, and gain confidence. Only when the new solution is demonstrably complete is the spreadsheet archived read-only.

What matters is supporting the people who work with the spreadsheets today. Excel solutions are almost always the work of committed employees – a replacement that devalues their work fails. A replacement that turns them into key users of the new solution carries itself almost automatically.

Costs, Benefits, and the Right Moment

What does it cost to replace Excel? The honest answer: less than expected if you start small. A single interface or the replacement of a single critical spreadsheet is a manageable project of weeks, not months. The counter-calculation is usually clear: search times, duplicate data maintenance, transfer errors, and the correction of faulty evaluations cost money continuously – just invisibly, spread across many workplaces. How this effect can be quantified is shown in our article on the ROI of IT modernization.

The right moment is rarely "when it burns." Anyone who only acts when the central costing file is corrupted or a data protection request exposes the e-mail attachments is renovating under pressure. The better occasions are plannable ones: an upcoming system change, new growth, a succession in the team – or simply the insight from the inventory that too much business depends on too fragile files.

Conclusion

Replacing Excel does not mean abolishing Excel. It means giving every task the right tool again: spreadsheets for analyses, databases for shared data, interfaces for exchange, and automation for recurring processes. Companies that take this step in a structured way win three times over – reliable figures, less manual work, and the certainty that critical knowledge does not live in a single file. And anyone looking at their grown system landscape along the way will find the right big-picture view in our article on the warning signs for legacy system replacement.

References

1. (Panko, R. – What We Don't Know About Spreadsheet Errors Today (EuSpRIG 2015))
2. (Microsoft – Excel specifications and limits)
3. (BBC – Excel: Why using Microsoft's tool caused Covid-19 results to be lost)
4. (EuSpRIG – Horror Stories)