The Goal of Availability Management is to ensure that level of service availability is delivered in all services is matched to or exceeds the current and future agreed needs of the business in a cost-effective manner. Availability is one of the most critical parts of the warranty of a service. If a service does not deliver the levels of availability required, then the business will not experience the value that has been promised. Without availability the utility of the service cannot be accessed. Availability management process activity extends across the service lifecycle.
The Objectives of Availability Management process are to:
Produce and maintain an appropriate and up to date availability Plan, that reflects the current and future needs of the business.
Provide advice and guidance to all other areas on availability related issues.
Assist with diagnosis and resolution of availability related incidents and problems.
Asses the impact of all changes on the Availability Plan, and the performance, and capacity of services and resources.
Ensure that proactive measures are implemented to improve the availability of services wherever it is cost justifiable. In short, Availability management should always ensure that the agreed level of availability is provided. The measurement and monitoring of IT availability is a key activity to ensure availability levels are being met.
Availability Management – Basic Concepts
Lets have a look at few key concepts of Availability Management
Availability: In simplest terms, the ability of a service, component or CI to perform its agreed function when required. This term answer the question, is it available to use when needed?
Reliability: A measure of how long a service, component or CI can perform its agreed function without interruption. When we understood the availability, thequestions comes, how long the service will be available? This can be answered by reliability.
Maintainability: A measure of how quickly and effectively a service, component or CI can be restored to normal after a failure. The emphasis is on how soon or how quickly the services can be back to BAU.
Serviceability: The ability of a third party supplier to meet the terms of their contract. Often this contract will include agreed levels of availability, reliability and / or maintainability for a supporting service or component. Serviceability and Maintainability are often confusing terms however the key differentiating term here is involvement of third party suppliers to restore the service or component.
Understanding Basic Concepts of Availability Management
Let’s understand these four terms Availability, Reliability, Maintainability, Serviceability Take an example of typical incident Lifecycle.
The moment incident is detected and it is restored, delta of that time is called MTTR or Mean Time to Repair and can be termed as the Serviceability IF a third party supplier was involved.
After restoration to the occurrence of next incident, the time when service was available to use is known as MTBF or Mean Time Between Failures and can be termed as Availability.
Maintainability can be explained by time taken to repair; shorter the time, greater the maintainability.
And finally time period between the two incidents is known as MTBSI or Mean Time Between System Incidents and can be termed as Reliability. Components with a high reliability factor mostly remain in high demand like some companies provide MTBSI rating along with their networking components such as routers.
Availability Management – Key Role
The Availability Management process includes two types of activities:
These involve monitoring, measuring, analysis and management of all events, incidents and problems involving unavailability. These activities are principally performed as part of the operational roles.
These involve the proactive planning, design and improvement of availability. These activities are principally performed as part of the design and planning roles. The key role of Availability Manager who is expected to involve in the activities like:
Responsible for Availability Management process
Participate in IT infrastructure design
Monitor actual IT availability achieved
Create, maintain & review AMIS and Availability Plan
Availability testing schedule
Testing after major business change
Assess impact of changes on Availability Plan
Attending CAB meetings
Ensure cost justified levels of IT availability Assessment and management of risk