The Excel and Email Trap: Why Spreadsheets Become Your Shadow Operating System

2025-09-24

Executive Summary

• Excel and email become the de facto operating system not because employees resist learning new tools. It’s because they’re more flexible, easier to customize, and solve problems that the official system can’t address in operational reality.
• “Shadow IT” — the informal operating layer — is a symptom of the gap between how formal systems were designed and how the organization actually needs to operate.
• The risk doesn’t come from using Excel. The risk comes from critical knowledge becoming dispersed, uncontrolled, and potentially lost at any moment.
• The solution isn’t to ban Excel — it’s to understand why Excel exists and address the underlying need.

A picture many CEOs recognize but don’t want to admit

The business has invested in an ERP or management software system. Implementation is complete. Employees have been trained.

But one year later, if you look at how operations actually run day to day, the picture looks like this:

• The weekly production plan gets distributed by email and tracked in an Excel file that everyone saves to their own machine.
• The list of urgent orders is maintained in a spreadsheet that the department head manually updates every morning.
• Batch status gets asked through messaging apps and the answers get compiled into an email to the manager.
• Quality inspection results go into a “QC team’s own Excel file” because the form in the software “doesn’t match how we actually do it.”

The ERP still runs. The software still works. But operations are happening somewhere else.

This isn’t the story of one specific organization. It’s a pattern common enough to have its own name: shadow IT — the informal operating layer that develops alongside official systems.

Shadow IT in manufacturing — not a habit, a rational response

When asked why employees still use Excel after new software has been deployed, the typical answer is: “habit,” “resistance to change,” “we need more training.”

These answers aren’t entirely wrong — but they miss something more important: Excel persists because it solves a real problem that the official system doesn’t solve well enough.

Consider each case.

Why does the production plan still live in Excel?

Because the software requires data entry in a rigid structure that doesn’t reflect how plans actually change throughout the day. Excel allows fast edits, inline notes, color coding for priority — things the software doesn’t allow easily or requires too many steps to accomplish.

Why are urgent orders tracked in a separate spreadsheet?

Because the main system has no easy way to flag “urgent” according to the manager’s actual logic: “urgent because a specific customer asked,” “urgent because material is about to expire,” “urgent because management requested it.” Excel allows organizing information according to that logic; the software doesn’t.

Why does the QC team have its own Excel file?

Because the form in the software was designed for a standard inspection procedure, but this organization’s actual inspection process has product-specific steps that the standard form doesn’t capture.

In each case, Excel isn’t there because of laziness — it’s there because it does something the official system doesn’t do well enough for the actual operational reality.

Why Excel never fully gets replaced — three advantages no dedicated software can easily match

Understanding why Excel persists requires recognizing three characteristics that make it genuinely superior in everyday use.

Advantage 1 — Infinite structural flexibility

Excel has no fixed schema. Users can structure information according to whatever logic they need — and change that logic immediately.

Dedicated software has a predefined schema. When operational reality doesn’t match that schema — and this happens more often than expected — users encounter friction: more steps to enter the same data, inability to capture what they actually need, or workarounds using fields for unintended purposes.

That friction is why Excel wins in daily practice, even when the software is theoretically better.

Advantage 2 — Instant analysis and presentation

Excel isn’t just a data storage tool — it’s an analysis and presentation tool. Users can filter, sort, calculate, and create charts in the same file without exporting to another tool.

Dedicated software tends to be good at one function — input, tracking, or reporting — but for ad hoc analysis, users still export to Excel. And once data is in Excel for analysis, people start adding more information to that Excel file.

Advantage 3 — No IT required to change

Any user can add a new column, restructure a table, or create a new tab in Excel immediately — no IT ticket, no waiting for customization, no deployment.

In a manufacturing environment, operational needs change constantly and can’t wait for IT. Excel lets employees solve problems immediately. This is genuinely valuable — and also the source of the problem.

The risks of running on shadow systems

The points above aren’t a defense of Excel in all contexts. The problem isn’t Excel itself — it’s when Excel becomes the primary operating system rather than a support tool.

When that happens, specific risks emerge:

Knowledge becomes dispersed and uncontrolled

When different people or departments maintain separate Excel files, important information exists in multiple disconnected locations. No one has a complete picture. No one can control who is looking at which version or what changes are being made.

Data loss when key people leave

Excel files tend to be associated with the person who created them — named after the person, stored on a personal machine or in a personal folder. When that person leaves, the file may not be handed over, or may be handed over without anyone understanding how to use it.

This is one of the ways organizational knowledge disappears without anyone noticing — not because employees deliberately withhold it, but because the system wasn’t designed to capture and transfer it.

No audit trail

Excel has no clear edit history. Who changed what, when, and why — these questions have no easy answers in Excel.

In a compliance environment, this is a serious problem: there’s no way to demonstrate who approved what, when a decision was made, or based on what information.

Decisions made on unsynchronized information

When multiple people are working from different Excel files that aren’t synchronized, important decisions may be made based on different pictures of reality. This problem typically isn’t discovered until after the consequences have materialized.

The next step — not banning Excel

A common mistake when a CEO or IT Manager recognizes the scale of shadow IT is to respond by “banning Excel” or “mandating the official system.”

These responses usually fail — because they attack the symptom without addressing the root cause. Employees aren’t lazy or stubborn; they’re solving real work problems with the best tool available.

More effective approaches:

Understand what Excel is being used for.

Every important Excel file that exists represents an operational need the official system isn’t meeting well. Identifying those needs — without judgment, just understanding — is the first step.

Identify which files contain important knowledge.

Not all Excel files are equally important. But some contain operational knowledge whose loss would meaningfully affect the business. Those files need attention — not necessarily immediate migration to a software system, but at minimum being made visible, controlled, and backed up.

Address the underlying need, not just the tool.

If employees are using Excel because the main system is too rigid for real operational requirements, the solution isn’t to find a different rigid system. It’s to identify those requirements and find ways to meet them — whether through software customization, building new workflows, or accepting that some things still need Excel but managed more deliberately.

Conclusion

Excel and email persist in business operations not because employees won’t change. They persist because they do something the official system doesn’t do — more flexibly, faster, without waiting for IT.

When you understand that, the question changes from “how do we eliminate Excel?” to “what needs are being met by Excel, and how can those needs be met in ways that are more controlled, more shareable, and not dependent on a single person or file?”

That is a knowledge management question — not an IT question.

How many shadow systems is your organization running on?

→ Take the Knowledge Management Readiness Assessment to evaluate dependence on informal systems and identify priority areas to address.

Further reading:

• When Key Employees Leave: What They Take With Them (previous)
• The Knowledge-Creating Organization (pillar)
• From Individual Knowledge to Organizational Knowledge (cross-language)

Examples used are composite illustrative scenarios from common patterns in SME operations. “Shadow IT” is used broadly to describe informal systems and processes that supplement or substitute for official IT systems — not necessarily in the narrowest technical definition of the term.