Software Metrics Data Collection ◾ 193
• Operating system crash
• Application program aborted
• Service degraded
• Loss of data
• Wrong output
• No output
Mechanism describes how the failure came about. is application-
dependent classication details the causal sequence leading from the acti-
vation of the source to the symptoms eventually observed. is category
may also characterize what function the system was performing or how
heavy the workload was when the failure occurred. Unraveling the chain
of events is a part of diagnosis, so oen this category is not completed at
the time the failure is observed.
Cause is also part of the diagnosis (and as such is more important for
the fault form associated with the failure). Cause involves ...