Computer system, operation support method and operation support program for computer system

The present invention pertains to a computer system which is provided with a processor and a storage device. The storage device holds operating information pertaining to operations that have been performed, and environment information pertaining to the environment in which the operations were performed. The operating information includes first operating information pertaining to first operations that have been performed in a first environment, and second operating information pertaining to second operations that have been performed in a second environment. The environment information includes first environment information pertaining to the first environment, and second environment information pertaining to the second environment. The computer system: selects, on the basis of the difference between the first environment information and the second environment information, a method for modifying the operating information in order to reduce the difference between the first operating information and the second operating information, said difference being attributed to the difference in the environments in which the operations were performed; uses the selected modified method to modify the first operating information and/or the second operating information; and assesses the degree of similarity between the first operating information and the second operating information, at least one of which has been modified.