Editing Business continuity planning (section)

==Tiers of preparedness==
[[SHARE (computing)|SHARE]]'s seven tiers of [[IT disaster recovery|disaster recovery]]<ref>developed by SHARE's Technical Steering Committee, working with IBM</ref> released in 1992, were updated in 2012 by IBM as an eight tier model:<ref name=IBM.2012>{{cite web
|url=https://share.confex.com/share/118/webprogram/Handout/Session10387/Session%2010387%20Business%20Continuity%20Soloution%20Selection%20Methodology%2003-7-2012.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://share.confex.com/share/118/webprogram/Handout/Session10387/Session%2010387%20Business%20Continuity%20Soloution%20Selection%20Methodology%2003-7-2012.pdf |archive-date=2022-10-09 |url-status=live
|title=A Business Continuity Solution Selection Methodology |publisher=IBM Corp.
|author=Ellis Holman  |date=March 13, 2012}}</ref>
* '''Tier 0''' – '''No off-site data''' • Businesses with a Tier 0 Disaster Recovery solution have no Disaster Recovery Plan. There is no saved information, no documentation, no backup hardware, and no contingency plan. Typical recovery time: ''The length of recovery time in this instance is unpredictable''. In fact, it may not be possible to recover at all.
*'''Tier 1''' – '''Data backup with no Hot Site''' • Businesses that use Tier 1 Disaster Recovery solutions back up their data at an off-site facility. Depending on how often backups are made, they are prepared to accept ''several days to weeks of data loss'', but their backups are secure off-site. However, this Tier lacks the systems on which to restore data. Pickup Truck Access Method (PTAM).
*'''Tier 2''' – '''Data backup with Hot Site''' • Tier 2 Disaster Recovery solutions make regular backups on tape. This is combined with an off-site facility and infrastructure (known as a hot site) in which to restore systems from those tapes in the event of a disaster. This tier solution will still result in the need to recreate several hours to days worth of data, but ''it is less unpredictable in recovery time''. Examples include: PTAM with Hot Site available, IBM Tivoli Storage Manager.
*'''Tier 3''' – '''Electronic vaulting''' • Tier 3 solutions utilize components of Tier 2. Additionally, some mission-critical data is electronically vaulted. This electronically vaulted data is typically more current than that which is shipped via PTAM. As a result there is ''less data recreation or loss after a disaster occurs''.
*'''Tier 4''' – '''Point-in-time copies''' • Tier 4 solutions are used by businesses that require both greater data currency and faster recovery than users of lower tiers. Rather than relying largely on shipping tape, as is common in the lower tiers, Tier 4 solutions begin to incorporate more disk-based solutions. ''Several hours of data loss is still possible'', but it is easier to make such point-in-time (PIT) copies with greater frequency than data that can be replicated through tape-based solutions.
*'''Tier 5''' – '''Transaction integrity''' • Tier 5 solutions are used by businesses with a requirement for consistency of data between production and recovery data centers. There is ''little to no data loss'' in such solutions; however, the presence of this functionality is entirely dependent on the application in use.
*'''Tier 6''' – '''Zero or little data loss''' • Tier 6 Disaster Recovery solutions ''maintain the highest levels of data currency''. They are used by businesses with little or no tolerance for data loss and who need to restore data to applications rapidly. These solutions have no dependence on the applications to provide data consistency. 
*'''Tier 7''' – '''Highly automated, business-integrated solution''' • Tier 7 solutions include all the major components being used for a Tier 6 solution with the additional integration of automation. This allows a Tier 7 solution to ensure consistency of data above that of which is granted by Tier 6 solutions. Additionally, recovery of the applications is automated, allowing for restoration of systems and applications much faster and more reliably than would be possible through manual Disaster Recovery procedures.