The only way to operate a construction machine efficiently is to improve the cost effectiveness. First, it is necessary to clarify the policy regarding owning and operating costs which directly concern cost effectiveness, and the location and standards for measuring reliability and maintenance activities which we face in connection with cost effectiveness.Next, it is important to have efficient maintenance support activities to improve the mechanical availability for the customer. However, for the customer, the support activity most concerned with maximizing profit is not simply maintenance problems. It is necessary to have support activities which go back to the source of the user's implementation processes. We would like to introduce what kind of systems are available for these support systems, and as it is now impossible to operate the systems without using the power of computers, we would like to give examples of comprehensive systems using hardware and software.