Avenryx SystemsPricing
What replacing a legacy system costs
The cost of modernisation is decided mostly by the state of the old data and how much undocumented behaviour is hiding in the old code. Both are knowable before you commit.
Outcomes
- Three costed routes compared
- Data quality assessed before pricing
- A phased plan with rollback points
- An indicative estimate in minutes
Pricing
Where it is used
Re-platform
Same behaviour, supported runtime — €60,000 to €150,000.
Phased strangler migration
Module by module, both systems live — €100,000 to €300,000.
Full rebuild
New process model and system — €250,000 upwards.
What we deliver
- Legacy data quality and volume
- Undocumented behaviour in the old system
- Number of integrations depending on it
- Downtime tolerance during cutover
- Regulatory retention of historic data
Who this is for
- Companies running a system nobody wants to change but everybody depends on.
- Teams costing a phased replacement against continued maintenance.
How delivery runs
- 01
Scoping
One to two weeks on the real workflow, systems and data. Output is a written scope and an indicative band.
- 02
Phased plan
The first usable release is identified explicitly so spend produces something usable early.
- 03
Fixed first phase
Phase one is quoted as a fixed price where scope allows; later phases are re-estimated with real velocity data.
- 04
Change log
Anything added after sign-off is estimated and scheduled in writing, so the budget never moves quietly.
Realistic timeline
Weeks 1–4
Assessment, rule recovery and slice plan.
Months 2–5
First slice replaced and running in parallel.
Months 6–12
Remaining slices, data migration and decommissioning.
Build or buy
Buy something existing when
- The legacy system covers a standard process a modern product now handles
Build custom when
- The system encodes business rules that exist nowhere else
We keep the old system running until each slice has proven itself in production.
What moves the price
Documentation and knowledge
Undocumented business rules must be recovered from code and from the people who use the system, which is investigative work.
Data model age
Decades of schema workarounds make migration the main cost, not the new interface.
Cut-over strategy
Strangler-pattern replacement in slices costs more in total than a big-bang rewrite and carries far less risk of losing the business.
Integration surface
Every downstream system reading the old database directly must be handled during transition.
Where projects go wrong
Budget set before scope
A number agreed before discovery is a guess. We give a band after a short scoping phase and narrow it once the workflow and integrations are documented.
Data migration priced last
Legacy data is rarely as clean as expected. We survey the actual export during discovery rather than assuming it at the end.
FAQ
Questions buyers ask
Is a rewrite always more expensive?+
Not always. When the process itself has changed, re-platforming old logic can cost more than building the right model once.
How do we reduce risk?+
Phasing, dual-run and reconciliation reporting. We rehearse the cutover before we do it.
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