What Does System Integration Mean?

System integration means to connect two systems, to make them talking. They exchange messages. Usually one of the systems is the client side – it sends requests to the other system. The second system is called the server side. It provides a service – a business function like a payment service, shipping service, healthcare service and so on. In other words the server side processes the request and returns the result – was the action successfully completed or not.

• API is a word you have heard several times. It defines the language between the systems. There are widely used APIs and custom APIs as well. Each API defines the actions that client can do – the various types of requests, for example createUser, calculateFee, transferAmount and many others.
• The Business analyst usually works on either side – client side or server side. Each system needs clear requirements for implementing the API. The server side needs requirements only in the context of the service provided – how exactly to transfer the amount, what fields to update, what response to return.
• The client side needs requirements in the context of the whole product offered, for example an online shop. When should the payment service be invoked – for example when the users confirms the order. What happens if the server side returns an error? All those conditions shall be well specified so that the developers and the QA can deliver a proper product as expected by the business.