A study on the reliability of the circuit maintenance system-1B

The Circuit Maintenance System (CMS)-1B has been developed to provide operational, administrative, and data base support to the trunk maintenance areas of the No. 4 ESS. In this paper, we investigate the reliability of the CMS-1B under the most stringent situation where six No. 4 ESSs are supported simultaneously. Our study results indicate that, with its current hardware arrangements, software structure, and administrative procedure, the CMS-1B can meet the reliability objective. Furthermore, the reliability of the CMS-1B is insensitive to an incremental change of its operating characteristics pertaining to the above three categories. We also provide a field-of-use guideline whereby the reliability of the CMS-1B can best be upgraded, if necessary. This guideline can be used by each CMS1-B site to decide whether its maintenance contract meets the response time requirement or its disk drive system needs to be replaced by a more reliable counterpart.