ERP Data Migration: The Traps Even Experienced Teams Miss

🧭 Introduction

Few areas in an ERP project are as underestimated as data migration.
It’s not glamorous, it’s not visible — but it often determines whether the go-live is a success or a failure.

Even experienced teams fall into the same traps: unclear responsibilities, incomplete validations, or misaligned priorities between IT and Finance.
Here are the most common pitfalls — and how to avoid them.

⚠️ 1. The Trap of Diffused Responsibility

“Everyone is kind of responsible… which means no one really is.”

• The data migration lead role is often poorly defined.
• IT extracts, consultants transform, but business owners (Finance, Procurement, HR) rarely perform deep validation.
• Without a clear RACI, errors remain hidden until cutover.

🧩 FitGap Solution:

Build a dedicated RACI matrix for data migration.
Validation should belong to the business — not just the implementation partner.
(Internal link: fitgapfinance.com/erp-raci-roles-responsibilities)

🧮 2. Underestimating the Complexity of Historical Data

“We’ll only migrate two years of data — that’ll be quick.”
In reality, existing data is rarely clean or consistent.

• Minimize transactional data migration and focus on balances instead.
• When transactions are carried forward, ensure reconciliations between subledgers and GL (inventory, open invoices, etc.).
• ERP projects often involve a paradigm shift — new cost structures, new dimensions, new accounting logic.
  → Don’t underestimate the effort needed for manual interpretation when predefined rules can’t be applied.
• Source data is rarely perfect: don’t wait for the new system to fix legacy quality issues.
  Fix root problems early to avoid migrating inconsistencies and unexplained variances.

💡 Pro Tip:

Don’t aim for perfection. Loosen the rules for historical data if needed —
for example, allowing a more flexible account structure for legacy data can save weeks of unnecessary rework.

🧾 3. Ignoring Financial and Operational Validation

Business users often validate “on paper” without checking accounting impacts.

• Reconciliations between the legacy and new systems are incomplete.
• Post-migration reports don’t align with how Finance actually reads the data.
• Result: discrepancies and frustration from day one of closing.

📊 Best Practice:

For each domain (GL, AR, AP, FA, Inventory), define reconciliation reports to be signed off before go-live.
Set an official data sign-off process with identified accountable owners in advance.
(Internal link: fitgapfinance/cfo-regain-control-tech-projects)

🧱 4. Neglecting Cutover Strategy and Cross-Team Coordination

“We’ll decide the cutover dates later.”

• Key decisions around cutover strategy (freeze periods, target dates, parallel run duration, etc.) are often delayed.
• Yet they directly impact go-live readiness and data integrity.
• These choices must be validated collectively — IT, Finance, operations, and partners.

🧭 Good Practice:

Always target the end of a fiscal or accounting period for your cutover.
Clearly define and communicate transaction freeze windows.
Ensure cutover timing aligns with financial close obligations.
(Internal link: fitgapfinance.com/erp-cutover-planning-step-most-teams-underestimate/)

🧰 5. Failing to Plan for Post-Go-Live Support

Data migration work doesn’t end on go-live day.

• Conversion errors often trigger support tickets for weeks.
• End users lack tools to correct or reimport data.
• And above all, organizations frequently underestimate how long it takes to absorb a new data structure.

🧭 Good Practice:

Avoid enforcing overly rigid controls right after go-live (e.g., a strict account hierarchy).
Allow time for users to adjust to the new structure and develop confidence in it.

Establish a post go-live correction procedure (“Quick Fix Process”)
and keep your pre-production environment active for several weeks after deployment.

🧩 In Summary

A successful data migration isn’t about perfect scripts —
it’s about clear governance, financial validation, and realistic expectations of what the business can absorb.

🎯 Golden rule: what you don’t validate before go-live, you’ll end up fixing afterward — at a much higher cost.

📘 Download the ERP RACI Matrix

To eliminate gray areas in your project, download our full ERP RACI Matrix:
ERP RACI Roles & Responsibilities (EN)