PPT Slide

System Reliability

• Specify Reliability Measures
  • “Up time,” the amount of time the system is functional, e.g. “system shall be up and fully operational 95% of the time”
  • “Down time,” e.g. “down time shall not exceed four hours per month”

• Define the terms -- does “down” mean completely unusable, some functions not working, or it fails to perform specified mission critical functions?

• Define penalties for unacceptable reliability

• Require reliability consistent with system mission, and remember higher reliability = higher cost