An IS auditor performing an independent classification of systems should consider a situation
where functions could be performed manually at a tolerable cost for an extended period of time as:
Sensitive functions are best described as those that can be performed manually at a tolerable cost
for an extended period of time. Critical functions are those that cannot be performed unless they
are replaced by identical capabilities and cannot bereplaced by manual methods. Vital functions
refer to those that can be performed manually but only for a brief period of time; this is associated
with lower costs of disruption than critical functions. Noncritical functions may be interrupted for
anextended period of time at little or no cost to the company, and require little time or cost to restore.