What type of tasks are performed to ensure the delivery of a service request?

The type of tasks performed to ensure the delivery of a service request are predefined tasks. This choice is correct because predefined tasks are established processes or steps that have been documented and standardized within an organization to fulfill service requests efficiently and consistently. These tasks help in managing service delivery effectively, ensuring that service requests are handled within agreed-upon service levels and quality standards.

Predefined tasks are integral to IT Service Management (ITSM) practices because they allow for automation, reduce the potential for errors, facilitate training, and enhance overall user satisfaction by providing a reliable service experience. They are typically outlined in service catalogues or standardized operating procedures, detailing exactly how service requests should be processed and fulfilled.

In contrast, ad-hoc tasks are generally spontaneous and not documented, which can lead to inconsistency in service delivery. Custom tasks, while potentially useful for specific situations, do not typically apply to standard service requests that benefit from structured workflows. Optional tasks imply a lack of necessity or are not essential for the completion of the service request, which undermines the goal of ensuring timely and effective service delivery.