Service Delivery is the management of the IT services themselves. The 5 recognised disciplines are:
Service Level Management
Service Level Management is the primary management of IT services, ensuring that agreed services are delivered when and where they are supposed to be delivered.
Capacity Management is the discipline that ensures IT infrastructure is provided at the right time in the right volume at the right price, and ensuring that IT is used in the most efficient manner.
Contingency planning is the process by which plans are put in place to ensure that IT Services can recover and continue should a serious incident occur. See the contingency planning page for more information.
Availability Management is the practice of identifying levels of IT Service availability for use in Service Level Reviews with Customers.
Cost Management for IT Services
Cost Management is the discipline of ensuring IT infrastructure is obtained at the most effective price (which does not necessarily mean cheapest), and calculating the cost of providing IT services so that an organization can understand the costs of its IT services.