“Only one person understands our old system, and they’re retiring.”
Legacy software rewrites, part of Operational workflows: replace the old system without stopping the business.
Plenty of firms still run on an Access database, a VB6 or .NET Framework application, a classic ASP or old PHP site, or a set of spreadsheets one person understands. It works until the person leaves, the server can no longer be patched, or a customer asks for something it cannot do. We rewrite these systems as maintained, modern software. The business keeps trading throughout: we move the data across, run old and new side by side where it matters, and switch over in phases.
What it does for your business
The business side first. The software comes later.
Off the unsupported platform
Software on supported, patched technology, so security updates and new starters stop being a worry.
Rules written down
The business rules buried in the old system are found, written down, tested and built into the new one.
No big-bang switch-over
Old and new run side by side where needed, and each part moves across once it has been checked against real data.
A system others can maintain
Clear code, documents and tests, so your own team or another supplier can take it on.
What it has done for clients
| The cost today | What changes | Proof |
|---|---|---|
| Contracts, sales and production software that was slow in places and risky to change | Modernised module by module in fixed two-week blocks, then handed to an in-house specialist we helped recruit | Oldham Engineering |
| A weak link between the business system and the shop floor | The ERP link upgraded, and a link to the shop-floor automation started | Oldham Engineering |
| Payroll comparisons run in spreadsheets by a few experts | A repeatable process in software, with a record of every decision | Global HR |
Source: Oldham Engineering and Global HR case studies, 2021 to 2026.
How a rewrite runs
- 1
Assess the old system
We find out what it does, what data it holds, who relies on it and which rules live only in the code.
- 2
Plan the move
A fixed-scope plan: what gets rebuilt first, how the data moves and how each part switches over without stopping work.
- 3
Rebuild in stages
Each stage is tested against real data and runs alongside the old system until the results match.
- 4
Switch over and retire
People move across a part at a time. When the last part has moved, the old system is archived and switched off.
Questions
Can you work from a system with no documents?
Yes, that is the usual case. We read the code and the database, watch people use it, and write down the rules as we find them.
Do we have to stop using the old system?
No. It keeps running until each part of the new one has been checked. Switch-over happens in phases, at times that suit the business.
What happens to our data?
It moves across with checks at each stage: record counts, totals and spot checks your team signs off. The old data is archived and kept.
Is it cheaper to keep patching the old system?
Sometimes, for a while. The assessment sets out what it costs to keep it, what it costs to replace it and the risk of each, so you can choose.
How is a rewrite priced?
It depends on the size of the system. We quote the assessment after a short call, and the assessment ends in a fixed price for the rewrite.
Start with an assessment
Book a free call and tell us about the old system. We then quote an assessment of what it does and how to replace it without stopping work.
Max RevittFounder and Director