A key component when negotiating with a software-as-a-service provider or hosting facility is the Service Level Agreement. SLAs, however, are used for more than just vendor-customer relationships.

SLAs are used by many businesses and government agencies to help define their internal computing infrastructure.

An SLA defines the services to be provided by the IT folks, and the associated levels of availability, response and maintenance. SLA’s also help to establish the computing budget for the organization.

The biggest concern in an SLA is typically with availability, or how often a system must be accessible and usable, and how quickly a system must be brought back online in case of any problem that renders it inoperable.

Internet-based software applications targeted at the general public typically must be available on a 24/7 basis. Typically measured in “nines,” the most common measurement for websites is referred to as the “five nines.” That is, the system must be operable for 99.999 percent of the time. This means that in a year the system can be down only five minutes and 15 seconds, for any reason, planned or unplanned.

Typically, even in this day and age, businesses and government agencies do not need to achieve five nines for their operational software. Achieving this status can be extremely expensive, and most traditional (non-Internet-based) organizations still don’t operate 24/7.

Defining the “uptime” requirements requires a cooperative approach between IT and the general business folks within the organization. Collectively, the cost of downtime on the business must be gauged. This cost is both tangible, such as lost revenue, as well as intangible, such as diminished business reputation.  How much downtime can your business stomach during a normal business day? Four hours? Two hours? Less?

Systems costs should be established appropriately for each option, and once an option is selected, the budget must be both allocated as well as adhered to. After all, the A in SLA stands for agreement, and that is what has been established by the business as a whole. 

In case of downtime, as long as the system is back online as defined in the SLA, the event is deemed successful. While it may seem odd, as long as the requirements of the SLA have been satisfied, the system is determined to be properly operating.