Risk Analysis
10.14 The extent of security measures required to be put in place depends on an
assessment of risks and the perceived impact of these risks on business. The countermeasures
would also depend on the extent of damage that these risks can pose to
business and the estimated financial implication of such counter-measures. Risk
analysis is not a one-time effort and needs to be carried out at periodic intervals in
order to factor in changes taking place in technology, new threats emerging and the
vulnerability of IT systems to such threats and the need to ensure that the current
controls in place are working effectively.
10.15 Risk analysis involves:
• business modelling to determine which information systems support which
business functions;
• impact analysis to determine the sensitivity of key business functions to a
breach of confidentiality, integrity or availability;
• dependency analysis to determine points of access to information systems and
assets that must be in place to deliver a service to a business function; and
• threat and vulnerability analysis to determine points of weakness in the
system configuration and the likelihood of events that would exploit the
weaknesses identified to cause impacts in terms of a breach of confidentiality,
integrity or availability.
10.16 The following diagram illustrates the relationship between the various aspects
of security that need to be considered in order to reduce the risk to an acceptable level: