Аннотация:Cloud interoperability is a new problem that is becoming evident as more cloud providers offer competing clouds and more enterprises migrate their applications into the cloud environments. However, for large enterprises the problem lies in enterprise software and middleware non-interoperability and overall complexity more than in the cloud providers incurred issues. In this paper we analyze cloud interoperability issues for existing enterprise applications based on our substantial enterprise IT transformation experience. We believe that adoption of stricter enterprise application development and maintenance policies and their enforcement coupled with PaaS clouds’ quick middleware provisioning and configuration capabilities will allow easy, predictable, fast, and inexpensive application rebuilds on-demand. This, in turn, will allow much cheaper application transformations, adoption of new technologies, and migrations between various clouds and non-cloud environments. We evaluate our policies based on three real-life applications from large corporations and show that strict application documentation and standardization results in at least an order of magnitude cost reduction of cloud application migrations.