Hydraulic excavators 1 working in fields each include a controller 2, and an operating time is measured for each of an engine 32, a front 15, a swing body 13 and a track body 12. The measured data is stored in a memory of the controller 2, transferred to a base station computer 3 through satellite communication,...http://www.google.ca/patents/US6449884?utm_source=gb-gplus-sharePatent US6449884 - Method and system for managing construction machine, and arithmetic processing apparatus
