||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.