Planned business interruptions

What interrupts your business? If you’re like the majority of IT sites, the answers could include system installations and upgrades, general system maintenance, application migrations and upgrades, performance degradation, and disasters.  Note two things about this list:  1) All but the last two are actually the result of planned downtime; 2) Planned downtime may represent as much as 90% of total downtime for most business systems.

The idea of planned downtime has been with us ever since the earliest computer (probably, the Jacquard loom).  Back in the days of mainframes and super-minis, it was a given that systems went offline for backups and every other sort of maintenance.  And while that went on, users – and their businesses – could do nothing but wait.

At most sites today, the maintenance window is still a part of standard IT operating procedure.  We are all aware however, that although reliance on maintenance windows has not changed over the last several years, the business climate has.  All large enterprise IT operations now operate 24-7 to support worldwide e-commerce.  If a business system has to go offline for any reason, IT managers know that it does so with the consequence that revenue is going to be impacted. 

Because of this, maintenance windows – whether they are used for backups or for any other service – are fast becoming a historical artifact. 

IT directors who find themselves signing off on a service-level agreement (SLA) that guarantees minimal downtime for any reason simply cannot afford to build-in time for offline maintenance of any sort.  After all, signing off on an SLA that assures “four nines” worth of business continuity means that your clients have been promised less than 53 minutes of downtime per year.  If you care to do the math, and you accept that planned downtime represents about 90% of the total, that leaves you with only 5.25 minutes of unplanned downtime each year. 

How many IT systems in your shop are really stable enough to guarantee no more than 5 minutes of downtime each year?  You decide.

There are an increasing number of options from a wide spectrum of vendors to make your business systems pervasively available.  Consider replication.  Consider clusters.  But please consider something.

Here is a useful first step:  accept that now is the right time to stop thinking in terms of “planned downtime,” and to start calling those maintenance windows what they really are – planned business interruptions.