An apparatus for evaluating a change of an existing system to a modified system by using a test system including a subsystem having the same configuration with either of the existing subsystem and the modified system includes: a memory for storing configuration information of the test system and test information; and a processor for executing a process including: activating the test system to execute test on the subsystem, collecting test information from the test system, and storing the test result information while the subsystem has the same configuration as the existing system; confirming the test system has been modified; and activating the test system to execute test on the subsystem, collecting test result information from the test system, and storing the test result information while the subsystem has the same configuration as the modified system.