Bespoke systems
Should you integrate existing systems or replace one of them?
Do not replace a sound system to fix one unreliable transfer of information.
Published 25 September 2026
Find out which system owns the fact
For each important field, identify where it is created, who may change it and how a correction reaches other tools. An integration without that rule can spread a wrong value very efficiently.
Trace one case across the applications. If users repeatedly leave a system to complete the core task, replacement may be justified. If the task works and only the transfer fails, an integration is the narrower bet.
Compare disruption as well as cost
Integration needs monitoring, error handling and care when either vendor changes. Replacement adds migration, retraining and a period in which old and new records may coexist. Price both operating burdens, not just implementation quotes.
Start with a representative workflow and define what would make the targeted repair inadequate. That test can prevent a large migration; it can also provide the evidence to defend one.
A customer record is reliable in one application, but staff copy its status into another each afternoon.
Test a managed transfer and a rule for conflicting statuses. Replacing the first application would migrate a large body of stable work to solve one narrow failure.