Estimating device and system

A system equipped with a plurality of machine tools, a management server configured to manage each of the plurality of machine tools, and a mobile terminal configured to communicate with at least one of the management server and the plurality of machine tools, the system comprising:

• a storage unit configured to store in association with each other state history information showing, as a history, a state of electrical equipment which is included in each of the machine tools and in which an abnormality has occurred, and cause history information showing, as a history, a cause of the abnormality;
• an acquisition unit configured to acquire state information indicating the state of the electrical equipment which is included in each of the machine tools and in which the abnormality has occurred;
• a detection unit configured to detect, from among a plurality of the state history information stored in the storage unit, at least one of the state history information that is similar to the state information acquired by the acquisition unit;
• and
• a notification unit configured to issue a notification concerning the cause of the abnormality, on a basis of the cause history information that is associated with the state history information detected by the detection unit.