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Business Impact Analysis for Business

Continuity

Maximum Acceptable Outage (Denition): Te Maximum Acceptable Outage

(MAO) is te maximum amount of time a system can be una!ailable before

its loss "ill compromise te organi#ation$s ob%ecti!es or sur!i!al& 

Maximum Tolerable Do"ntime (Denition): Te maximum lengt of time a

business function can be 'iscontinue' "itout causing irreparable arm to

te business&

eco!ery oint Ob%ecti!e (O): A reco!ery point ob%ecti!e* or +O,* is

'ene' by business continuity planning& It is te maximum targete' perio'in "ic 'ata migt be lost from an IT ser!ice 'ue to a ma%or inci'ent&

eco!ery Time Ob%ecti!e: Te reco!ery time ob%ecti!e (TO) is te targete'

'uration of time an' a ser!ice le!el "itin "ic a business process must be

restore' after a 'isaster (or 'isruption) in or'er to a!oi' unacceptable

conse-uences associate' "it a brea. in business continuity&

Mean Time Bet"een /ailure :(MT/0MTB/): Mean time bet"een failures (MTB/)

is te pre'icte' elapse' time bet"een inerent failures of a system 'uring

operation&123 MTB/ can be calculate' as te aritmetic mean (a!erage) timebet"een failures of a system&

Mean Time to epair0eco!er (MT0MTT): Mean Time To epair (MTT) is a

basic measure of te maintainability of repairable items& It represents te

a!erage time re-uire' to repair a faile' component or 'e!ice&123 4xpresse'

matematically* it is te total correcti!e maintenance time 'i!i'e' by te

total number of correcti!e maintenance actions 'uring a gi!en perio' of

time&

Consider the following scenario.

5tage 2: Business as usual

http://en.wikipedia.org/wiki/Business_continuity_planninghttp://en.wikipedia.org/wiki/Datahttp://en.wikipedia.org/wiki/Business_processhttp://en.wikipedia.org/wiki/Business_continuityhttp://en.wikipedia.org/wiki/Mean_time_between_failures#cite_note-1http://en.wikipedia.org/wiki/Arithmetic_meanhttp://en.wikipedia.org/wiki/Failurehttp://en.wikipedia.org/wiki/Repairablehttp://en.wikipedia.org/wiki/Arithmetic_meanhttp://en.wikipedia.org/wiki/Mean_time_to_repair#cite_note-1http://en.wikipedia.org/wiki/Corrective_maintenancehttp://en.wikipedia.org/wiki/Datahttp://en.wikipedia.org/wiki/Business_processhttp://en.wikipedia.org/wiki/Business_continuityhttp://en.wikipedia.org/wiki/Mean_time_between_failures#cite_note-1http://en.wikipedia.org/wiki/Arithmetic_meanhttp://en.wikipedia.org/wiki/Failurehttp://en.wikipedia.org/wiki/Repairablehttp://en.wikipedia.org/wiki/Arithmetic_meanhttp://en.wikipedia.org/wiki/Mean_time_to_repair#cite_note-1http://en.wikipedia.org/wiki/Corrective_maintenancehttp://en.wikipedia.org/wiki/Business_continuity_planning

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At this stage all systems are running production and working correctly.

5tage 6: Disaster occurs

On a given point in time, disaster occurs and systems need 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 1 minutes.

5tage 7: eco!ery

At this stage the system is recovered and back online but not ready for production yet. !he 

Recovery Time Objective (RTO) determines the maximum tolerable amount of time needed to

 bring all critical systems back online. !his covers, for example, restore data from back"up or fix

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of a failure. #n most cases this part is carried out by system administrator, network administrator,

storage administrator etc.

5tage 8: esume ro'uction

At this stage all systems are recovered, integrity of the system or data is verified and all critical

systems can resume normal operations. !he Work Recovery Time (WRT) determines themaximum tolerable amount of time that is needed to verify the system and$or data integrity. !his

could be, for example, checking the databases and logs, making sure the applications or services

are running and are available. #n most cases those tasks are performed by application

administrator, database administrator etc. %hen all systems affected by the disaster are verified

and$or recovered, the environment is ready to resume the production again.

!he sum of &!O and %&! 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 conse'uences. !his value should be defined by the business management team or

someone like C!O, C#O or #! manager.

!his is of course a simple example of a (usiness Continuity$)isaster &ecovery plan and should

 be included in your Business Imact !nalysis (BI!).