A method for automatic diagnosis of a specific mechanical system of a group of mechanical systems sharing mechanical characteristics, the method comprising: obtaining vibration-related data relating to a vibration of the specific mechanical system, the vibration-related data being acquired by a portable communications device configured to communicate with a remote processing unit; and operating the remote processing unit to automatically diagnose the specific mechanical system by applying a relationship between the vibration-related data and states of operation of mechanical systems of a group of mechanical systems the method being characterized by: the relationship being based on a plurality of sets of vibration-related data previously obtained from the group of mechanical systems sharing mechanical characteristics, each set of vibration-related data relating to vibrations of one mechanical system of the group of mechanical systems sharing mechanical characteristics, the relationship being further based on a plurality of sets of operational data previously obtained for mechanical systems of the group of mechanical systems sharing mechanical characteristics, the operational data including data that defines a malfunction or breakdown of said mechanical systems, each set of operational data indicating a previous state of operation of one mechanical system of the group of mechanical systems sharing mechanical characteristics, each of the previous states of operation being associated with at least one of the previously obtained sets of vibration-related data; analyzing the plurality of sets of vibration-related data from the group of mechanical systems sharing mechanical characteristics and the plurality of sets of operational data of the group of mechanical systems sharing mechanical characteristics, to obtain said relationship; and communicating said relationship to said portable communications device. obtaining vibration-related data relating to a vibration of the specific mechanical system, the vibration-related data being acquired by a portable communications device configured to communicate with a remote processing unit; and operating the remote processing unit to automatically diagnose the specific mechanical system by applying a relationship between the vibration-related data and states of operation of mechanical systems of a group of mechanical systems the method being characterized by: the relationship being based on a plurality of sets of vibration-related data previously obtained from the group of mechanical systems sharing mechanical characteristics, each set of vibration-related data relating to vibrations of one mechanical system of the group of mechanical systems sharing mechanical characteristics, the relationship being further based on a plurality of sets of operational data previously obtained for mechanical systems of the group of mechanical systems sharing mechanical characteristics, the operational data including data that defines a malfunction or breakdown of said mechanical systems, each set of operational data indicating a previous state of operation of one mechanical system of the group of mechanical systems sharing mechanical characteristics, each of the previous states of operation being associated with at least one of the previously obtained sets of vibration-related data; analyzing the plurality of sets of vibration-related data from the group of mechanical systems sharing mechanical characteristics and the plurality of sets of operational data of the group of mechanical systems sharing mechanical characteristics, to obtain said relationship; and communicating said relationship to said portable communications device. the relationship being based on a plurality of sets of vibration-related data previously obtained from the group of mechanical systems sharing mechanical characteristics, each set of vibration-related data relating to vibrations of one mechanical system of the group of mechanical systems sharing mechanical characteristics, the relationship being further based on a plurality of sets of operational data previously obtained for mechanical systems of the group of mechanical systems sharing mechanical characteristics, the operational data including data that defines a malfunction or breakdown of said mechanical systems, each set of operational data indicating a previous state of operation of one mechanical system of the group of mechanical systems sharing mechanical characteristics, each of the previous states of operation being associated with at least one of the previously obtained sets of vibration-related data; analyzing the plurality of sets of vibration-related data from the group of mechanical systems sharing mechanical characteristics and the plurality of sets of operational data of the group of mechanical systems sharing mechanical characteristics, to obtain said relationship; and communicating said relationship to said portable communications device.