Absolutely no organisation can exist without the application of one or more forms of ICT. The traditional information systems are taken into consideration, but also the business use of the Internet (web applications, ASP, e commerce) and electronic cooperating and exchanging information (intranet, extranet, EDI, EFT, XBRL, supply chain management).
Both internal and external parties want to be certain that the technology which is used in the organisation works well and reliably. The legislation has become very important regarding the quality of the ICT (e.g. Sarbanes-Oxley, certification). That's why ICT-assurance has become a necessity.