1. A computer system comprising a management computer, among a plurality of computers, for dividing a job including data and a program for processing the data into a plurality of divided jobs and managing them, and a plurality of execution computers for executing divided jobs assigned by the management computer among the plurality of divided jobs, wherein each execution computer generates a job request including information about the number of the divided jobs based on a load on each execution computer and sends the generated job request to the management computer; and wherein when the management computer receives the job request from each execution computer, it assigns a divided job to each execution computer according to the number of divided jobs included in the job request.