Arsenault

A manufacturing firm in the Midlands relies on an ERP system installed when Tony Blair was still in office. The software works, or at least it limps along. The real issue is not the software itself. It is the people expected to keep it alive.

Most of the current IT team were not even born when the first version of this system went live. To them, the architecture is not a tool. It is ancient history. This gap between legacy technology and modern human capital creates a silent drain on resources that most balance sheets fail to capture.

Many business leaders view an ERP readiness assessment as a box ticking exercise. It feels like a delay. It feels like an unnecessary cost when the goal is to get the new system live as soon as possible. I have seen this mindset play out across dozens of implementations. The urge to bypass the groundwork is understandable, especially when pressure from stakeholders to modernise is high. Yet, skipping this phase is rarely a strategic shortcut. It is usually the first step toward a very expensive failure.

You spend months planning, invest heavily in consultants, and run test migrations that look flawless on paper. Then go live hits, and the system collapses under the weight of incorrect customer records, duplicated inventory codes, and financial balances that refuse to reconcile. The project spirals into crisis mode, budgets double, and the board starts asking uncomfortable questions.

Every year, organisations pour significant capital into ERP migration projects. Some of those investments pay off with streamlined operations and better data visibility. Many others stall midstream, drain budgets, and leave teams worse off than before the migration began. The difference rarely comes down to technology alone. It comes down to the decisions made before a single record gets moved.

If you are planning to legacy ERP migration and move to a modern platform, the five mistakes below represent the most expensive pitfalls I have seen organisations stumble into.