Dictionary of Modernization
"The replatform strategy involves moving applications almost as-is, but replacing some components to take advantage of the cloud. For example, moving application from AIX based Websphere legacy to Websphere Liberty. Try to identify low-hanging fruit—applications that require only small optimizations before moving to the cloud. In many cases, this involves switching from self-hosted infrastructure to managed services. Another common optimization is switching from commercial software to open source. This can allow you to scale freely on the cloud without worrying about the licensing cost of each additional instance. Even though this strategy involves small modifications or swapping of components, for production applications, you must conduct extensive testing, deploy on the cloud and then monitor for an extended period. Pay attention to performance, basic functionality and user metrics—if conversion rates or shopping cart completions are down, there could be a problem."