When an image processing apparatus acquires job log information and error log information from an image forming apparatus, the information processing apparatus identifies a job processing time from a job start time and a job end time of each job which are recorded in the acquired job log information. Subsequently, the information processing apparatus identifies a job suspension time from an occurrence time and a recovery time of an error of each log which is recorded in the error log information. Then, the information processing apparatus calculates a job execution time based on the identified job processing time and the job suspension time.