---
title: "Legacy software rewrites"
url: "/services/legacy-software-rewrites"
canonical_url: "https://revitt.co/services/legacy-software-rewrites"
summary: "Legacy software rewrites, part of Operational workflows: replace the old system without stopping the business."
---

# Legacy software rewrites

> 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

- **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 we deliver

- **Access databases**: Replaced with a multi-user system your staff can reach safely from anywhere.
- **VB6 and .NET Framework applications**: Desktop and server applications rewritten on supported technology.
- **Classic ASP and old PHP systems**: Web systems that can no longer be patched, rebuilt with the data kept.
- **Spreadsheet-run processes**: Critical spreadsheets turned into software with checks and a record of changes.
- **Unsupported in-house apps**: Systems whose developer has gone, taken over, documented and replaced.

## Process

01. **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.
02. **Plan the move**: A fixed-scope plan: what gets rebuilt first, how the data moves and how each part switches over without stopping work.
03. **Rebuild in stages**: Each stage is tested against real data and runs alongside the old system until the results match.
04. **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.

## FAQs

**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.

## Case studies

- https://revitt.co/case-studies/oldham-engineering
- https://revitt.co/case-studies/global-hr

## Next step

- [Book a call](https://revitt.co/book.md)
- [Send a brief](https://revitt.co/contact.md)