1. A job scheduling management method for managing schedules of jobs allocated to a plurality of computers connected through a network, comprising the steps of: monitoring a performance state of a resource of a computer, included in said plurality of computers, to which said jobs have been allocated, wherein said performance state includes first information indicating at least one of a usage rate of a Central Processing Unit (CPU) included in said computer, an amount of memory being used in said computer, an amount of empty space on a disk storage device included in said computer, an average processing time for the disk storage device, and an average query processing time for a database application being executed by said computer; determining if said performance state meets a predetermined condition, wherein the determining is based on how many times said usage rate of said CPU exceeds a predetermined usage rate; if said performance state meets said predetermined condition, detecting a job, of said jobs allocated to said computer, that is uncompleted at a time when said predetermined condition is met; detecting a resource that is available to execute said detected uncompleted job based on second information concerning resources required for executing said detected uncompleted job, wherein said second information includes an inter-resource distance which is a cost value taken between an execution computer and resources of said plurality of computers, respectively when the execution computer of said computers uses an available resource included in a plurality of resources usable by said computers, the cost being defined as a value representing efficiency for use of said resources; allocating said detected uncompleted job to said detected resource; managing information indicating correspondence between said job and a time when said job is to be finished and information indicating a tome passed in executing said job; and determining that said predetermined condition is not met and allocating the uncompleted job of said jobs allocated to said computer to another computer if said management computer predicts that said job is not finished in the time when said job is to be finished from the performance state of said computer that executes said job and said time required for executing said job.