Business continuity (BC):

• BC is an integrated and enterprise wide process that includes all activities (internal and external to IT) that a business must perform to mitigate the impact of planned and unplanned downtime.

• Business continuity encompasses a loosely defined set of planning, preparatory and related activities which are intended to ensure that an organization's critical business functions will either continue to operate despite serious incidents or disasters that might otherwise have interrupted them, or will be recovered to an operational state within a reasonably short period. As such, business continuity includes three key elements:

1. Resilience: critical business functions and the supporting infrastructure are designed and engineered in such a way that they are materially unaffected by most disruptions, for example through the use of redundancy and spare capacity;

2. Recovery: arrangements are made to recover or restore critical and less critical business functions that fail for some reason.

3. Contingency: the organization establishes a generalized capability and readiness to cope effectively with whatever major incidents and disasters occur, including those that were not, and perhaps could not have been, foreseen.

• It involves proactive measures, such as business impact analysis and risk assessments, data protection, and security, and reactive countermeasures, such as disaster recovery and restart, to be invoked in the event of a failure. The goal of a business continuity solution is to ensure the “information availability” required to conduct vital business operations.

  Information Availability

  Information availability (IA) refers to the ability of the infrastructure to function according to business expectations during its specified time of operation. Information availability ensures that people (employees, customers, suppliers, and partners) can access information whenever they need it. Information availability can be defined with the help of reliability, accessibility and timeliness.

  • Reliability: This reflects a component’s ability to function without failure, under stated conditions, for a specified amount of time.

  • Accessibility: This is the state within which the required information is accessible at the right place, to the right user. The period of time during which the system is in an accessible state is termed system uptime; when it is not accessible it is termed system downtime

  • Timeliness: It defines the exact moment or the time window (a particular time of the day, week, month, and/or year as specified) during which information must be accessible. For example, if online access to an application is required between 8:00 am and 10:00 pm each day, any disruptions to data availability outside of this time slot are not considered to affect timeliness.

Disaster Recovery

This is the coordinated process of restoring systems, data, and the infrastructure required to support key ongoing business operations in the event of a disaster. It is the process of restoring a previous copy of the data and applying logs or other necessary processes to that copy to bring it to a known point of consistency. Once all recoveries are completed, the data is validated to ensure that it is correct.

Recovery Point Objective

This is the point in time to which systems and data must be recovered after an outage. It defines the amount of data loss that a business can endure. A large RPO signifies high tolerance to information loss in a business. Based on the RPO, organizations plan for the minimum frequency with which a backup or replica must be made. For example, if the RPO is six hours, backups or replicas must be made at least once in 6 hours. An organization can plan for an appropriate BC technology solution on the basis of the RPO it sets. For example:

• RPO of 24 hours:This ensures that backups are created on an offsite tape drive every midnight. The corresponding recovery strategy is to restore data from the set of last backup tapes.

• RPO of 1 hour:This ships database logs to the remote site every hour. The corresponding recovery strategy is to recover the database at the point of the last log shipment.

• RPO of zero:This mirrors mission-critical data synchronously to a remote site.