Disasters are inevitable but mostly unpredictable, and they vary in type and magnitude. The best strategy is to have some kind of disaster recovery plan in place, to return to normal after the disaster has struck. For an enterprise, a disaster means abrupt disruption of all or part of its business operations, which may directly result in revenue loss. To minimize disaster losses, it is very important to have a good disaster recovery plan for every business subsystem and operation within an enterprise.
This paper discusses an approach for creating a good disaster recovery plan for a business enterprise. The guidelines are generic in nature, hence they can be applied to any business subsystem within the enterprise.
In the IT subsystem, disaster recovery is not the same as high availability. Though both concepts are related to business continuity, high availability is about providing undisrupted continuity of operations whereas disaster recovery involves some amount of downtime, typically measured in days. This paper focuses only on disaster recovery.
Every business disaster has one or more causes and effects. The causes can be natural or human or mechanical in origin, ranging from events such as a tiny hardware or software component’s malfunctioning to universally recognized events such as earthquakes, fire, and flood. Effects of disasters range from small interruptions to total business shutdown for days or months, even fatal damage to the business.
The process of preparing a disaster recovery plan begins by identifying these causes and effects, analyzing their likelihood and severity, and ranking them in terms of their business priority. The ultimate results are a formal assessment of risk, a disaster recovery plan that includes all available recovery mechanisms, and a formalized Disaster Recovery Committee that has responsibility for rehearsing, carrying out, and improving the disaster recovery plan.
When a disaster strikes, the normal operations of the enterprise are suspended and replaced with operations spelled out in the disaster recovery plan. Figure 1 depicts the cycle of stages that lead through a disaster back to a state of normalcy.