Explanation/Reference:
The recovery time objective (RTO) is the duration of time and a service level within which a business process must be restored after a disaster (or disruption) in order to avoid unacceptable consequences associated with a break in business continuity.
It can include the time for trying to fix the problem without a recovery, the recovery itself, testing, and the communication to the users. Decision time for users representative is not included.
The business continuity timeline usually runs parallel with an incident management timeline and may start at the same, or different, points.
In accepted business continuity planning methodology, the RTO is established during the Business Impact Analysis (BIA) by the owner of a process (usually in conjunction with the business continuity planner). The RTOs are then presented to senior management for acceptance.
The RTO attaches to the business process and not the resources required to support the process.
The RTO and the results of the BIA in its entirety provide the basis for identifying and analyzing viable strategies for inclusion in the business continuity plan. Viable strategy options would include any which would enable resumption of a business process in a time frame at or near the RTO. This would include alternate or manual workaround procedures and would not necessarily require computer systems to meet the RTOs.
For your exam you should know below information about RPO, RTO, WRT and MTD :
Stage 1: Business as usual
Business as usual
Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-01.png At this stage all systems are running production and working correctly.
Stage 2: Disaster occurs
Disaster Occurs
Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-02.png On a given point in time, disaster occurs and systems needs to be recovered. At this point the Recovery Point Objective (RPO) determines the maximum acceptable amount of data loss measured in time. For example, the maximum tolerable data loss is 15 minutes.
Stage 3: Recovery
Recovery
Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-03.png At this stage the system are recovered and back online but not ready for production yet. The Recovery Time Objective (RTO) determines the maximum tolerable amount of time needed to bring all critical systems back online. This covers, for example, restore data from back-up or fix of a failure. In most cases this part is carried out by system administrator, network administrator, storage administrator etc.
Stage 4: Resume Production
Resume Production
Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-04.png At this stage all systems are recovered, integrity of the system or data is verified and all critical systems can resume normal operations. The Work Recovery Time (WRT) determines the maximum tolerable amount of time that is needed to verify the system and/or data integrity. This could be, for example, checking the databases and logs, making sure the applications or services are running and are available.
In most cases those tasks are performed by application administrator, database administrator etc. When all systems affected by the disaster are verified and/or recovered, the environment is ready to resume the production again.
MTD
Image Reference - http://defaultreasoning.files.wordpress.com/2013/12/bcdr-05.png The sum of RTO and WRT is defined as the Maximum Tolerable Downtime (MTD) which defines the total amount of time that a business process can be disrupted without causing any unacceptable consequences. This value should be defined by the business management team or someone like CTO, CIO or IT manager.
The following answers are incorrect:
RPO - Recovery Point Objective (RPO) determines the maximum acceptable amount of data loss measured in time. For example, the maximum tolerable data loss is 15 minutes.
WRT - The Work Recovery Time (WRT) determines the maximum tolerable amount of time that is needed to verify the system and/or data integrity. This could be, for example, checking the databases and logs, making sure the applications or services are running and are available. In most cases those tasks are performed by application administrator, database administrator etc. When all systems affected by the disaster are verified and/or recovered, the environment is ready to resume the production again.
MTD - The sum of RTO and WRT is defined as the Maximum Tolerable Downtime (MTD) which defines the total amount of time that a business process can be disrupted without causing any unacceptable consequences. This value should be defined by the business management team or someone like CTO, CIO or IT manager.
The following reference(s) were/was used to create this question:
CISA review manual 2014 page number 284
http://en.wikipedia.org/wiki/Recovery_time_objective
http://defaultreasoning.com/2013/12/10/rpo-rto-wrt-mtdwth/
