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Service · Data & Integration
Legacy ERP modernization in stages you can control
Many mid-sized businesses still run on an ERP installed fifteen or twenty years ago — an on-premise system on an unsupported version, or a custom application written by a developer who has since left. It works, mostly. But it cannot connect to modern tools, finding people who understand it gets harder every year, and each change feels dangerous.
Overview
What legacy erp modernization involves
Replacing it all at once is often the riskiest option. We help businesses modernise in stages: stabilise what exists, wrap it with APIs so new tools can connect, and move functions to a modern platform one area at a time.
01The problem
Where things usually go wrong
01
Unsupported platform
The vendor no longer issues updates, and the hardware or OS underneath is ageing too.
02
Shrinking expertise
One or two people understand the system, and they are close to retirement.
03
Integration dead end
No APIs, so every connection to a modern tool is a nightly file or manual re-entry.
04
Big-bang fear
A full replacement feels so risky that nothing happens at all.
02Our approach
How we handle it
We start with an assessment: what the legacy system actually does, which functions are business-critical, how data is structured and what depends on it. From there, we choose a strategy per functional area — retain, wrap, replace or retire.
A common pattern is to put an integration layer around the legacy system first, so modern tools (eCommerce, CRM, BI) can connect without touching it directly. Functions then move to the new platform in phases — perhaps finance first, then inventory, then manufacturing — with data synchronised between old and new during the transition.
03Capabilities
What the work covers
01
Legacy assessment
Functional, technical and data review of the existing system.
02
Strategy per area
Retain, wrap, replace or retire decisions with rationale.
03
API wrapping
Integration layer exposing legacy data to modern tools safely.
04
Phased replacement
Functional areas moved to a modern ERP one at a time.
05
Coexistence sync
Data synchronised between legacy and new systems during transition.
06
Decommissioning
Archive, access and shutdown plan for the old system.
04Technical considerations
Details that decide whether it holds up
01
Reverse engineering
Documenting undocumented business rules from code, data and user knowledge.
02
Database access
Safe read access to legacy databases without impacting performance.
03
Strangler pattern
New functionality built around the old system until it can be switched off.
04
Data lineage
Tracing where each data element originates during coexistence.
05Process
How the engagement runs
- 01
Assess
Understand the legacy system and its dependencies.
- 02
Plan
Choose a strategy per area and sequence the phases.
- 03
Wrap
Add an integration layer to unlock data.
- 04
Replace in phases
Move functional areas to the new platform.
- 05
Retire
Archive data and decommission the legacy system.
06Outcomes
What you should expect afterwards
Lower risk
Smaller, reversible steps instead of a single high-stakes cutover.
Earlier value
Modern tools connect sooner, before full replacement is complete.
Captured knowledge
Hidden business rules documented before the people who know them leave.
Where it applies
Industries and systems we commonly see
Relevant industries
Relevant integrations
Related services
Often delivered alongside
ERP MigrationMove from one ERP to another — processes, data, integrations and people — without losing control.ERP Data MigrationScripted, repeatable, reconciled movement of master data, open items and balances.ERP API IntegrationDesign and build ERP APIs, webhooks and connectors with security and reliability built in.Custom ERP DevelopmentPurpose-built ERP software for operations that standard products fit poorly.
Insights
Related reading
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FAQ
Frequently asked questions
Is a phased modernization always better than a big-bang replacement?
Not always. Smaller businesses with a simple footprint may be better off with a single, well-rehearsed cutover. Phasing helps most when the legacy system is deeply embedded or the business cannot tolerate a large-scale disruption.
How long does legacy modernization take?
It varies widely with scope. A phased programme often spans twelve to twenty-four months, with each phase delivering value on its own.
Can you work with systems on AS/400 or old databases?
Yes, provided we can access the data. We regularly extract from older databases and file-based systems.
Next step
Running the business on an ageing ERP?
We will assess it and propose a modernization path you can actually execute.