A method for a device, including an integrity information collecting step S10 of measuring and collecting a time consumed from a start time of one operation to an end time in a normal state of a device; a defect information collecting step S20 of measuring and collecting a time consumed from a start time of one operation to an end time in a state of a device; a setting step S30 of setting an integrity reference value and a defect reference value for the time consumed for one operation of the device; a detecting step S40 of measuring and collecting a time value consumed from a start time of an operation of the device to an end time in real time and detecting an integrity index value of the device; and an outputting step S50 of outputting the integrity index value.