T 1.2 Failure of the IT system

Failure of a single component in an IT system can result in failure of the entire IT operation. Such failures are especially likely to occur where faults develop in components which are central to the IT system, e.g. LAN server or data transmission facilities. Failure of components of the technical infrastructure, for example air conditioning or power supply facilities, can also help induce an IT system failure.

Technical failure (e.g. T 4.1 Disruption of power supply) should not necessarily be assumed to be the cause when an IT system fails. Failures are often also the result of human error (e.g. T 3.2 Negligent destruction of equipment or data) or wilful action (e.g. T 5.4 Theft, T 5.91 Sabotage). Loss or damage may also be caused by force majeure (e.g. fire, lightning, chemical accident), although in such cases the scale of the damage is likely to be considerably higher.

If any time-critical IT applications are run on an IT system, the consequential damage following a system failure may be expected to be extensive unless there are alternatives available.

Examples

• Due to voltage spikes in the power supply, the power supply unit for an important IT system is destroyed. As the IT system concerned is an older model, replacement parts are not available immediately. Repairs take a whole day to perform and during this time the entire IT operation is at a standstill.

• Firmware is loaded onto an IT system for which it is unsuited. The IT system will no longer start without errors and has to be repaired by the manufacturer.

• A power failure in an Internet Service Provider' main memory system resulted in this being shut down. Although it was possible to fix the actual error quite quickly, the IT systems affected would not boot up correctly as there were inconsistencies in the file system. Several of the WWW servers operated by the ISP remained out of action for days until all the consequential problems had been resolved.