How systems are connected.
WHAT FILE TRANSFER MEANS
Exporting from one system and importing into another, on a schedule.
WHAT IT SUITS
Batch processes, where delay is acceptable.
WHAT IT COSTS
Latency, and fragility if formats change.
WHAT DIRECT DATABASE ACCESS MEANS
One system reading another's database.
WHY TO AVOID IT
It bypasses business logic, and breaks on upgrade.
WHAT INTERFACES PROVIDE
A supported way for systems to exchange data.
WHY THAT IS PREFERABLE
The vendor maintains compatibility.
WHAT MESSAGE-BASED INTEGRATION PROVIDES
Systems publishing events, consumed by others.
WHAT IT SUITS
Several systems reacting to the same event.
WHY IT IS MORE ROBUST
Systems are decoupled, and a consumer being unavailable does not block the producer.
WHAT INTEGRATION PLATFORMS PROVIDE
Connectors, transformation and monitoring, without custom code.
WHAT THEY COST
Subscription, and dependence on another vendor.
WHAT POINT-TO-POINT INTEGRATION PRODUCES
A connection between each pair of systems.
WHY THAT BECOMES UNMANAGEABLE
The number of connections grows rapidly with systems.
WHAT AN INTEGRATION LAYER PROVIDES
Each system connecting once, to the layer.
WHAT TO CHOOSE
The simplest approach meeting the requirement.
