Business Continuity
Business Continuity (Availability) has found widespread use in IT technology literature as a Turkish word. From here, Uninterruptible Power Supply and other critical physical infrastructure providers have started to use this word when defining their own systems. This word does not fully reflect the definition, and naturally creates ambiguity in thoughts and conversations. As a word, “Availability” has the meaning of being ready, usable, available, and available. One of the most appropriate terms is the definition of being “ready for service” used in the generator sector.
Business Continuity is defined in its true meaning as the strategic and tactical skills of institutions in responding to ordinary or extraordinary situations and planning for such situations, and the ability to continue business practices at a predefined acceptable level for business interruptions.
Business continuity, which means “availability” used for data center critical infrastructure systems and their configuration, is defined numerically with definitions such as MTBF and MTTR, and also has a mathematical connection with the definition of “reliability”. These are statistical definitions. They present a numerical analysis that describes the performance of a system or infrastructure while performing its task.
Although reliability and availability are closely related, it is useful not to confuse them. It is important for a spacecraft, nuclear submarine or aircraft to complete their tasks flawlessly, primarily to protect human life. Therefore, the reliability of these systems must be high. In order to prevent any negative incidents while underway, each critical element must be manufactured and assembled with high reliability. In fact, for the high reliability of these vehicles, their use is interrupted for maintenance. During this period, all elements that have completed their lifespan (are no longer reliable) are replaced and tested. The systems become able to start their tasks with high reliability.
On the other hand, the availability of these highly reliable systems is low. Because they are not ready for use during maintenance and testing.
The performance of Data Center critical infrastructure systems is measured by high availability rather than high reliability. Data center infrastructure; It is required to continue its duty even in maintenance, human error, failure, environmental and natural risks. Continuing the infrastructure duty during maintenance or replacement works is an important performance.
Therefore, it is more important for critical physical infrastructure systems to be structured with backups and to be tolerant to failures rather than having a high reliability structure. Thus, infrastructures with high business continuity (availability) can be created by using more economically suitable commercial products. In other words, this situation can be achieved by integrating systems that will support each other in maintenance or risk situations instead of using a high-cost system.
The simplest business continuity (availability) definition used in Information Technology assessment is 9s. It is used to explain with what percentage the system remains standing in a year and how many interruptions there are with a simple calculation.
For a sense, an example can be given that the telephone system standard targets a business continuity of 99.999%. This standard is valid for a wired telephone in a home. When the telephone is lifted from the receiver in a year, there should be a 99.999% probability that the dial ring will ring (be ready for service). A total of 5 minutes a year may not have a phone dial tone. Normally, a user will not even notice these 5 minutes since they will be the time the phone is not used.
It is impossible for this phone standard to be valid for mobile phones. Because in any case, the battery power of the mobile phone will run out, and it will be difficult for the user to use it with such high business continuity.
The business continuity need is different according to the characteristics of wired telephone and mobile phone systems. As in the example given, not every data center may need the same level of business continuity. Determining the business continuity level of the Data Center is an important heading for the initial investment cost and design. Determining the business continuity level according to the purpose of use of Data Centers is important in this respect.
Data center infrastructure business continuity is defined according to the continuity of the operation of the critical devices it hosts, providing power, cooling and security needs. On the other hand, the business continuity of the data center’s network infrastructure and fiber backbone connection, the healthy operation of the servers and storage devices, and the uninterrupted service of the application software will determine the holistic business continuity. Naturally, i Central infrastructure business continuity will be the most determining ratio. It is impossible to maintain service in the upper layers without energy and cooling.