System simulation testing: Pre-delivery testing to ensure system dependability

When customers develop a new computer system, their main concern is trouble-free performance. However, as the systems grow in size and complexity it becomes more and more difficult to guarantee their total dependability. In order to ensure the system's reliability, which is required by customers, Hitachi validates them by executing an integrated pre-delivery testing called system simulation testing (SST). SST uses specialized tools for modeling and testing user systems. SST is classified into four types such as; functional and operational tests; error recovery test; evaluation of efficiency; and heavy load test. Since 1977, about 2500 SST tests have been executed effectively.