Machine tool management system that obtains a next maintenance period from a maintenance period model and a refinement algorithm

A machine tool management system, comprising:

• an external server;
• and
• a plurality of numerical controller (NC) devices connected to the external server through a network, the NC devices controlling respective machine tools,
• wherein the external server is configured to collect operating information obtained from the NC device of each machine tool, and comprises:
• storing unit storing a maintenance period model and a refinement algorithm in advance;
• changing unit changing a computational expression of the maintenance period model by the refinement algorithm;
• and
• computing unit obtaining a next maintenance period from the maintenance period model,
• wherein a maintenance of at least one of the machine tools is executed in accordance with the next maintenance period obtained by the external server, and
• wherein an initial set value of the maintenance period model is T=T0, and the next maintenance period is expressed by the refinement algorithm:
• T=T0·[(1+tn1/T0)·(1+tn2/T0)···(1+tn1/T0)]·[(1−tm1/T0)·(1+tm2/T0)···(1+tmj/T0)]
• m1, m2 . . . mj denote signals associated with shortening of a maintenance part life,
• tm1, tm2 tmj denote accumulated time of each corresponding signal m1, m2 . . . mj within the maintenance period,
• n1, n2 . . . ni denote signals associated with extension of the maintenance part life,
• tn1, tn2 tni denote accumulated time of each corresponding signal n1, n2 . . . ni within the maintenance period, and
• i and j are positive integers greater than 1.