PURPOSE: To shorten the time needed for change of the operational conditions and to save the labor needed for that time, by always monitoring the operating situation of a computer system and securing the automatic change of the operating situation based on the monitor data.

CONSTITUTION: The operational conditions are recognized by a monitor means 1 and the state of the queue for abnormal data is delivered to a deciding means 2. The means 2 compares the working conditions stored in a system operational condition memory device 11 with the data delivered from the means 1. If it is judged from said comparison that the abnormal values occurs frequently, the means 2 produces the operational condition value to be changed and informs it to a changing means 3. The means 3 converts the received operational condition value into a system forming parameter and stores it in the device 11. The means 3 gives an indication to a reflecting means 4 after change of the operational conditions. The means 4 reads the change information out of the device 11 and reflects it onto the system operation.