ABSTRACT
When a cloud service provider introduces Cloud to enterprises, it should be ready to address the needs of integrating the new cloud services with hundreds of existing systems. It needs to provide a smooth transition path for enterprise users to adopt cloud services over time. At the same time, when it extends existing enterprise applications to cloud, it often needs to migrate existing systems piece by piece. So, for a considerable period of time, it will face the situation that different parts of a bigger system work together over different environments, such as on-premise, private cloud, community cloud, and public cloud.
