The Schemes to Develop Dependable System Using COTS

This paper provides general design schemes for the dependable system especially long-term projects using commercial off the shelf (COTS) computers based on the concept we established for dependability. As computer technology has shown significantly rapid pace of evolution, it is necessary to take the evolution into consideration when we develop computer systems. Especially in a large-scale project, the evolutions in computer technology during its term are often seen; thus, it is necessary to establish simply applicable schemes as basic concepts to develop dependable system. Basic considerations are presented here by extruding its requirements for dependable systems from wide area railway systems requiring on-time traffic operation and safety under high-density traffic. Many dependable control systems have already been delivered based on autonomous decentralized concept using COTS systems and been showing their sufficient dependability.