1. There were two ways to improve the availability, one of them is to decrease the mean time to repair(MTTR), the other is to increase the mean time to fail(MTTF).

2. Checking results show that, MTTF and MTTR of whole province's 200MW set in fossile P. P. all accord with 2-parameter Weibull distribution.

3. Automatic Testing and Fault Isolation can make the MTTR of system be reduced, or enhance the availability of system.

4. Note 1: Mean-Time-To-Repair (MTTR) is defined as the average time taken from receiving customer fault report by ComNet telecom (HK) staff to restoring service to customers.

5. The MTTR is defined as a fuzzy number. The fuzzy numbers are used for evaluating system reliability, system MTTR and system failure rate.

6. The resulting system has improved manageability, by reducing the mean time to resolution (MTTR) for customer-impacting events caused by software availability, reliability and performance issues.

7. MTTR values listed assume complement of spares are available on site and do not include travel time to site.

8. In order to have the good maintainability, it is necessary to predict the indexes of maintainability at the stage of the design and demonstration of the equipment, especially, MTTR.

9. Key variables of equipment performance and life can be used to predict failure, provide alerts for maintenance action, increase uptime and lower MTTR.