A predictor management system includes a storage unit 81 and update history management means 82. The storage unit 81 stores, in association with each of a plurality of prediction targets, an update history of a predictor corresponding to the prediction target. The update history management means 82 stores, in response to updating of a predictor, a prediction target of the predictor and an update time of the predictor in the storage unit 81 in association with each other.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A predictor management system comprising: hardware including a processor; a storage unit storing, in association with each of a plurality of prediction targets, an update history of a predictor corresponding to the prediction target; and an update history management unit implemented at least by the hardware and stores, in response to updating of a predictor, a prediction target of the predictor and an update time of the predictor in the storage unit in association with each other. 2. The predictor management system according to claim 1, wherein the storage unit stores update histories of a plurality of predictors that differ in update time, and wherein the update history management unit stores an update history of the updated predictor in the storage unit further in association with the prediction target. 3. The predictor management system according to claim 1, wherein the update history management unit determines, depending on a predictor update method, a version number assigned in update order of predictors for predicting the same prediction target, and stores, in the storage unit, an update history of the predictor to which the version number is added. 4. The predictor management system according to claim 1, comprising a rearranging unit implemented at least by the hardware and which rearranges the plurality of prediction targets stored in the storage unit, according to an update frequency of the predictor corresponding to the prediction target, an update time interval of the predictor corresponding to the prediction target, or a time elapsed from a previous update of the predictor corresponding to the prediction target. 5. The predictor management system according to claim 1, comprising a classifying unit implemented at least by the hardware and which classifies the plurality of prediction targets stored in the storage unit into a plurality of groups, according to an update frequency of the predictor corresponding to the prediction target, a tendency of a change of an update time interval of the predictor corresponding to the prediction target, or a time elapsed from a previous update of the predictor corresponding to the prediction target. 6. The predictor management system according to claim 1, comprising a visualization unit implemented at least by the hardware and which generates a graph in which, for each of the plurality of prediction targets stored in the storage unit, a symbol representing updating of the predictor corresponding to the prediction target is located at a position corresponding to an update time of the predictor on a time axis provided for the prediction target. 7. The predictor management system according to claim 1, wherein the update history management unit stores, in response to updating of a predictor meeting a prediction accuracy degradation condition from among predictors, a prediction target of the predictor and an update time of the predictor in the storage unit in association with each other. 8. A predictor management method, implemented by a computer, storing, in response to updating of a predictor, a prediction target of the predictor and an update time of the predictor in a storage unit in association with each other, the storage unit storing, in association with each of a plurality of prediction targets, an update history of a predictor corresponding to the prediction target. 9. The predictor management method according to claim 8, wherein the computer stores, in response to updating of a predictor meeting a prediction accuracy degradation condition from among predictors, a prediction target of the predictor and an update time of the predictor in the storage unit in association with each other. 10. A non-transitory computer readable information recording medium storing a predictor management program, when executed by a processor, that performs a method for, storing, in response to updating of a predictor, a prediction target of the predictor and an update time of the predictor in a storage unit in association with each other, the storage unit storing, in association with each of a plurality of prediction targets, an update history of a predictor corresponding to the prediction target. 11. The non-transitory computer-readable recording medium according to claim 10, wherein the computer stores, in response to updating of a predictor meeting a prediction accuracy degradation condition from among predictors, a prediction target of the predictor and an update time of the predictor in the storage unit in association with each other.