Appendix: Solutions to Selected Exercises ◾ 539
total execution time on all instances of the soware during a
given calendar time period) are required.
ii. Location: e particular instance of the soware that failed,
identied by the installation on which it is running. In this
case, the control room will operate one (or more) instance(s)
of the CAM soware, and each taxi will operate an instance
of the COT soware.
iii. Mode: What symptoms were observed? at is, what was the
system seen to do that was not part of its required functions?
iv. Effect: What were the consequences of the failure for
the driver of the taxi and for the whole of the SCAMS
operation?
v. Severity: How serious were these consequences? (is may be
expressed eit ...