ThePearlRiver.com, Inc. is a New Orleans-based company that specializes in selling university apparel, fan gear, sports clothing on line. As an IT consultant, you are invited to conduct a system availability test for this company. Please show your calculation and indicate the degree of availability, i.e. the system type.

Based on the collected data, you find the system reliability (mean time between failures or MTBF) is about 2,920 hours. Mean time to repair or MTTR is about 10 hours. Also, the routine maintenance shutdown time is about 30 hours a year.

Total time = downtime + uptime,

Where total time = 365*24 = 8,760 hours

Downtime = repair time + shutdown time

Repair frequency total time/MTBF

Repair time = Repair frequency * MTTR

Availability: = (ratio of ) uptime/total time

The degree of availability/system type usually depends on the number of nines (9s) in the availability ratio. For example, if the calculate ratio is 99.96%, we can say there are three 9s, the system can be defined as "Well-Managed" according to the reference table below.