A management device comprising: a time series acquisition unit that is configured to acquire a plurality of continuous time series while the machine is in operation in a time series related to power consumption of a machine for a certain time; a classification unit that is configured to classify each of a plurality of time series in which the power consumption is higher than a threshold value in the plurality of time series into any one of a plurality of clusters; and a process estimation unit that is configured to estimate a process executed by the machine at a time related to the plurality of time series, based on relationship information indicating a relationship between the plurality of clusters and the process of the machine, and a type of the cluster into which the time series is classified, wherein the relationship information is information associating the cluster with the process, and in the relationship information, the process estimation unit estimates the process associated with the most frequent cluster among the clusters into which each of the plurality of time series is classified, as the process executed by the machine at the time related to the plurality of time series, or wherein the relationship information is information associating the cluster with the process, and in the relationship information, the process estimation unit estimates the process associated with a plurality of higher clusters which appear frequently among the clusters into which each of the plurality of time series is classified, as the process executed by the machine at the time related to the plurality of time series, or wherein the relationship information is information associating an appearance pattern of the cluster with the process, and in the relationship information, the process estimation unit estimates the process associated with an appearance pattern similar to the appearance pattern of the cluster into which each of the plurality of time series is classified, as the process executed by the machine at the time related to the plurality of time series. a time series acquisition unit that is configured to acquire a plurality of continuous time series while the machine is in operation in a time series related to power consumption of a machine for a certain time; a classification unit that is configured to classify each of a plurality of time series in which the power consumption is higher than a threshold value in the plurality of time series into any one of a plurality of clusters; and a process estimation unit that is configured to estimate a process executed by the machine at a time related to the plurality of time series, based on relationship information indicating a relationship between the plurality of clusters and the process of the machine, and a type of the cluster into which the time series is classified, wherein the relationship information is information associating the cluster with the process, and in the relationship information, the process estimation unit estimates the process associated with the most frequent cluster among the clusters into which each of the plurality of time series is classified, as the process executed by the machine at the time related to the plurality of time series, or wherein the relationship information is information associating the cluster with the process, and in the relationship information, the process estimation unit estimates the process associated with a plurality of higher clusters which appear frequently among the clusters into which each of the plurality of time series is classified, as the process executed by the machine at the time related to the plurality of time series, or wherein the relationship information is information associating an appearance pattern of the cluster with the process, and in the relationship information, the process estimation unit estimates the process associated with an appearance pattern similar to the appearance pattern of the cluster into which each of the plurality of time series is classified, as the process executed by the machine at the time related to the plurality of time series.