The paper describes the methodology of concurrent migration with optimal utilization of existing computer resources which has been used in organizations. Concurrent migration bypasses a transitional system which is described as migration model. Migration model includes modules for resource utilization, minimum modification, advance implementation, continuous utilization and concurrent development. Procedure for concurrent migration includes seven steps in which the migration system is included. A case study of concurrent migration of a centralized system converted to a distributed system based on remote/local (R/L) computing is presented to show the availability of the model and the procedure.