Business continuance (sometimes referred to as business continuity) describes the processes and procedures an organization puts in place to ensure that essential functions can continue during and after a disaster. Business continuance planning seeks to prevent interruption of mission-critical services, and to reestablish full functioning as swiftly and smoothly as possible.
Although business continuance is important for any enterprise, it may not be practical for any but the largest to maintain full functioning throughout a disaster crisis. According to many experts, the first step in business continuity planning is deciding which of the organization's functions are essential, and apportioning the available budget accordingly. Once the crucial components are identified, failover mechanisms can be put in place. New technologies, such as disk mirroring over the Internet, make it feasible for an organization to maintain up-to-date copies of data in geographically dispersed locations, so that data access can continue uninterrupted if one location is disabled.
According to a recent Gartner Group document, a business continuance plan should include: a disaster recovery plan, which specifies an organization's planned strategies for post-failure procedures; a business resumption plan, which specifies a means of maintaining essential services at the crisis location; a business recovery plan, which specifies a means of recovering business functions at an alternate location; and a contingency plan, which specifies a means of dealing with external events that can seriously impact the organization. Business continuance has become an increasingly common area of concern since the September 2001 World Trade Center disaster, in which an unforeseen incident created a sudden and severe threat to crucial functions for a number of companies.