ITIL (v2) is set of best practices for organisations to manage their IT services.

There are 4 lifecycle stages, one of which is Service Operation, which focuses on operating and maintaining IT systems until they are decommissioned. An IT system spends most of its life in this lifecycle. As in most cases, the person developing an application may not be the one maintaining it. Service Operation lists best practices to keep it running.

This stage is further broken down into 5 processes. A company that adheres to ITIL practices would have one team for each process, but that's not usually the case unless it's an international company.

Event management is a proactive activity to monitor an application throughout its life. Monitoring tools can be configured with predetermined thresholds to capture events. For example, a spike in traffic to an online store may be an event but not an incident.

Incident Management is the process of handling an incident from when it was first raised until it is closed. An event could turn into an incident. Incidents are unplanned interruptions or reduction in service quality. A slowness in network qualifies as an incident. Potential interruptions also qualify as incidents. In a large organisation in which many IT experts are required to resolve an incident, a incident manager needs to manage the communications between them.

The goal of Problem Management is to find a workaround (a temporary solution), conduct a root cause analysis and apply a fix. A problem is an underlying cause of one or more incidents. In ITIL terms, incidents do not turn into problems.

Access Management is the process of granting different levels of permissions to individuals that need to use an application. Principle of Least Privillege means that a person is granted just enough access for her to complete a task.

Knowledge Management is the newest process in this lifecycle stage. It is concerned with gathering, updating and sharing knowledge across the organisation. The Known Error Database is maintained and referred to for quick resolutions for recurring incidents.

The ITIL version 2 is a relatively strict guidance that focuses on maintaining systems. Newer practices adopt a more holistic approach in which a person may need to be more fluid and well-versed in more areas.