A manufacturing company rarely wants to replace its ERP. It wants the warehouse to stop typing the same delivery note twice, finance to stop reconciling by eye, and the sales team to see stock without asking anyone. The ERP stays; something has to be built around it.
That is where most integration projects get into trouble. Once three or four applications write into the ERP directly, nobody can say which one caused a wrong stock figure at 3am, and every upgrade becomes a gamble.
One door into the ERP
We build hub and spoke instead. Department applications never talk to the ERP. They post commands onto a bus, and exactly one bridge process is allowed to open the ERP connection and apply them. Everything that touches the ERP goes through a single, auditable door.
That one constraint buys a lot. Commands are idempotent, so a retry after a timeout cannot post the same movement twice. Jobs are claimed atomically, so two workers cannot process the same command. Every write leaves an audit record with who asked, what was sent and what came back.
Built for the shop floor, not the demo
Factory conditions are hostile to web applications. Wi-Fi drops behind a steel structure, tablets are used with gloves, and a scanner operator will not wait for a spinner. Department apps have to tolerate being offline, queue what they could not send, and make it obvious when something has not synced yet.
The same applies to permissions. A warehouse operator and a finance controller should not see the same screen or the same numbers, and that separation belongs in the database with row level security, not in a form that hides a button.
Where to start
The cheapest way to start is not a platform. It is an integration audit: what the ERP already exposes, which processes are duplicated by hand, and which single department would benefit most in six weeks. Then one department application, in production, with real users. Then the next.
Netsis is what we know deepest, but the architecture is not specific to it. Any ERP that is business critical and hard to change deserves exactly one door.