System and method for monitoring machine tool operations with superimposed chronological information

A display unit which displays information obtained from a machine tool that executes a machining program including a plurality of blocks as a plurality of program blocks identified by sequence numbers, the display unit comprising:

• a data acquisition unit which acquires, in real time, state information that indicates a state of the machine tool being operated as an amount of variation and a time axis, and timing information which indicates predetermined timing of the machining program executed by the machine tool;
• a chronological information generation unit which generates chronological information based on the state information and the timing information acquired;
• a superimposition unit which makes the timing indicated in the timing information coincide and which superimposes a plurality of pieces of the chronological information;
• and
• a display portion which displays the pieces of chronological information which are superimposed,
• wherein the data acquisition unit acquires, as the timing information, information of a start time of at least one of a plurality of sequences of the machining program executed by the machine tool and a finish time corresponding to the start time,
• the superimposition unit calculates a time difference between the finish times corresponding to the pieces of chronological information which are superimposed and
• the display portion displays the time difference which is calculated.