Embodiments of the claimed subject matter are directed to methods and a system that allows the optimization of processes operating on a multi-platform system (such as a mainframe) by migrating certain processes operating on one platform to another platform in the system. In one embodiment, optimization is performed by evaluating the processes executing in a partition operating under a proprietary operating system, determining a collection of processes from the processes to be migrated, calculating a cost of migration for migrating the collection of processes, prioritizing the collection of processes in an order of migration and incrementally migrating the processes according to the order of migration to another partition in the mainframe executing a lower cost (e.g., open-source) operating system.