Maintenance management system and data processing method

To prevent a delay in detection of a fault and the like and to cut down a load on a management side while making transmission of data appropriate in consideration of importance and properties of each type of the data in a case in which a large amount of data is transmitted from management target apparatuses. Items with high priority are processed first, and items with a low priority are allowed to be thinned out in accordance with priority and a weight that a management system 10 defines for each data item, thereby reducing a load. The thinning out is performed by limiting the number of data items to be processed once in accordance with a load level. Data acquisition intervals and priority for each item are dynamically changed by reflecting the importance of the data of each item and a change thereof. Trends of data and the like distributed using telemetry are observed and are fed back to load control through control using an AI or a rule base. In a case in which distribution intervals of each data item are changed, the distribution intervals are changed to a multiple of a basic cycle to curb influences on correlations among the items.