SAP HCI is made as Integration Platform-as-a-Company (PAAS) which helps you to combine multiple independent techniques/purposes for a business process. HCI can do Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid model. HCI delivers Adapters (Connectivity options) for instance: Cleaning soap Adapter, IDoc, HTTP, Mail, SFTP,Ariba, oData. https://s4-hana-cloud-trial65913.blogars.com/27712173/hana-cloud-integration