A job management server for managing a plurality of jobs to be executed by a virtual computer generated on a computer, a job management part to manage information on a job net which configures a plurality of jobs and allocate a plurality of jobs included in a job net to the virtual computer, and a recovery part to monitor an execution status of each of the plurality of jobs included in the job net and perform recovery processing, wherein the job management server is configured to: specify a target job for changing allocation, in a case where a failure has occurred in a first virtual computer to execute a first job included in the first job net; determine a performance of a virtual computer required to execute the target job.