In almost every business, digital systems arrive at different times, from different suppliers, with different logic. The management system, the CRM, support and project tools, and in industry the production systems. Each one works. The trouble is in between, where contracts, orders, jobs, tickets and invoices have to pass from one system to another.
Where the cost hides
When integration is weak, the work shifts to people and spreadsheets. Data gets re-keyed, lead times stretch, decisions are made on stale information. The cost appears on no line of the accounts, but it shows in margins, customer response times and deliveries.
Governing the boundary
Integration should be treated as something to design and govern, not as a technical detail of each project. That means deciding which system is the source of each piece of information, who owns it and how you check that the flows are working.
Before replacing a system, map these boundaries. The biggest benefit often comes not from the new software but from tidying up the flows around it.