Software Engineering, English, Swedish

fault tolerence August 25, 2008

6.2 Types of faults

Nature

random faults:

The primary cause of random faults is hardware component failure. Statistical analysis may make it possible to estimate the likelihood of it failing within a given period of time.

systematic faults (design faults):

mistakes in the specification of the system; mistakes in the software; and mistakes in the  hardware design

   Duration

   permanent faults:

       This kind of faults remain in existence indefinitely, or untill some corrective action is taken, are termed permanent faults. Design faults, including software faults, are always permanent, as are many hardware components.

   transient faults

   This kind of faults can appear and then disappear after a short time.

   intermittent faults

   These faults, appear, disappear and then reappear at some later time.

Extent

   localized fault

      It may affect only a single hardware or software module

   global fault

       It has effects which permeate throughout the system