Testing in a Complex Systems Environment

A complex systems environment as discussed herein is one in which a telecommunications network is attached to a computing complex. The computing complex is under control of an operating system and has one or more subsystems, such as IMS/VS (Information Management System / Virtual Storage), executing and communicating with remote terminals via the telecommunications network. User-written application programs, under control of the subsystem, execute upon demand from the remote terminals. Batch processing may also be performed concurrently. For testing, this environment is replicated in a laboratory environment, so that all physical portions of the environment need not be present.