In every ERP review I run, I ask the same question of the finance team, the warehouse manager and the sales administrator. "What would you do with the time the system currently takes from you?" The answers are always practical. Chase debts sooner. Check stock properly. Call the customer back today instead of tomorrow. Spend the evening with the family instead of rekeying.
This is the part of legacy ERP that never makes the business case: the human cost. It is harder to measure than a licence fee, which is exactly why it gets ignored, and it is the reason good teams quietly leave, one resignation at a time.
In this guide
The daily friction your board never sees
Old ERP systems tax their users in small ways that add up: a lookup that takes eight seconds instead of two, a screen that requires twelve clicks to do what should take three, a process that only works if you know the undocumented sequence of tabs and workarounds. None of these is a failure. Each is just enough friction to be felt, every single day.
Multiply that friction by the people who touch the system and you get a quiet productivity tax. The Chartered Institute of Personnel and Development's research on employee experience and wellbeing consistently shows how much daily frustration affects engagement. People do not leave jobs because of one bad day. They leave because the bad days repeat, and the system they complain about is the one constant.
The Federation of Small Businesses has documented the same pattern from the employer side in its research on workforce and skills: smaller teams feel every inefficiency more, because there is no spare capacity to absorb it. In a business of 200 people, one slow system touches all 200. In a business of 40, it touches all 40 and there is nobody left to cover.
Retention: the resignation ledger
There is a ledger nobody keeps: the cost of resignations caused, at least partly, by software. I have seen it repeatedly in client work. A credit controller with eight years of experience leaves, and the exit interview says "nothing, I have enjoyed my time". The real reason, shared only with colleagues, is that she was tired of reconciling three systems every month.
The replacement costs are real: recruitment fees, notice periods, training time, and the six months it takes a new person to learn the undocumented quirks of the old system. When you add that up, the arithmetic changes. The Federation of Small Businesses and the CIPD both put the cost of replacing a skilled employee at a significant multiple of their salary once you include lost output. An ERP that keeps your good people is not a perk. It is a retention strategy.
A wholesaler with 120 staff had lost three finance people in fourteen months. The pattern was identical: strong candidates joined, discovered the ERP could not handle multi-currency pricing without manual intervention, and left within a year. The board assumed the problem was salary. The exit data said otherwise. When we mapped the work, the manual pricing process took a senior analyst three hours a day. The replacement programme removed that process entirely. Eighteen months after go-live, the finance team had been stable for a year, and the business had stopped paying recruitment fees for the same role.
Shadow IT as a verdict on your system
Shadow IT is the most honest feedback you will ever get about your ERP. When a department buys its own tool, pays for it out of its own budget, and runs it alongside the official system, that department has voted. The official system failed them, and they found a workaround they control.
Do not blame the department. Their job is to get work done, and they found a way. The fault lies with the system that could not keep up. Shadow IT matters for three reasons:
- Data fragments. The same customer now exists in the ERP and in the department tool, with different values in each. Which one is true at month end is a game nobody wins.
- Cost hides. Department tooling is not in the IT budget, so the true cost of the ERP's limits is invisible. In the cost review I wrote about earlier, shadow licences were often a six-figure line.
- Risk spreads. Tools bought by departments rarely meet the security and data protection standards of the central estate. The ERP's weakness has exported your risk, not removed it.
A modern replacement programme should treat the discovery of shadow IT as a gift. Each tool is a requirement you did not know you had. Capture the workflow it supports, and make sure the new system does it properly. That is how you win the team back.
Involving users is not a courtesy, it is the plan
The failure mode of ERP projects is almost never the technology. It is adoption. And adoption is decided in the first two months, by whether the people using the system feel it was built for them or imposed on them.
In my experience the projects that land well share four habits:
- Users shape the requirements. The discovery workshops include the credit controller, not just the finance director. The requirements document is written in their language, about their processes.
- Prototypes are shown early. Users see the screens and workflows months before go-live, and their objections arrive while there is still time to act on them.
- Testing runs their scenarios. The test scripts use their real orders, their real products, their real edge cases. A test environment full of dummy data finds nothing.
- Users become the trainers. The superusers who helped design the system train their own departments. Credibility travels sideways better than it travels down.
This is why the planning phase matters so much, and it is covered in detail in planning an ERP change without disrupting daily operations. The operational checklist for go-live, including the training and communication tasks, is in the migration checklist nobody talks about.
Frequently asked questions
How does old software affect staff retention?
Good people in finance, operations and sales often leave roles where they spend hours fighting the system. Pay is not always the deciding factor; the daily friction of unusable software is. Fixing the system is often cheaper than replacing the team.
What is shadow IT and why does it matter?
Shadow IT is software that departments buy themselves because the central ERP will not do the job. It matters because it costs money outside the IT budget, fragments your data, and usually means your team has already decided the main system has failed them.
How should users be involved in an ERP replacement?
Involve them from discovery, not after design. Use their workflows to shape the requirements, show them early prototypes, run their scenarios in testing, and make them the trainers for their own departments. Adoption follows involvement.
Does a new ERP really save employee time?
In most replacement programmes the time saved is measurable in hours per person per week, mainly from removing rekeying, reconciliation and waiting. Those hours convert into either lower overtime or more output, depending on how the business chooses to use them.
The honest summary: your ERP is a retention tool, a morale tool and a productivity tool, whether you designed it that way or not. Right now it is doing all three poorly. A system your team does not have to fight is the cheapest way to keep the people you spent years finding.
