Cloudware Economics - Guide to Cloud Computing for Business and Technology Managers - page 298

• Optional services : This field specifies any services that are not nor-
mally required by the user but might be required in case of an
exception.
• Exclusion terms : These specify what is not covered in the SLA.
• Administration : This field describes the processes and the measur-
able objectives in an SLA and defines the organizational authority
for overseeing them.
SLAs can be either static or dynamic in nature. A static SLA is an SLA that
generally remains unchanged for multiple service time intervals. Service
time intervals may be calendar months for a business process that is subject
to an SLA or may be a transaction or any other measurable and relevant
period of time for other processes. They are used for assessment of the QoS
and are agreed between a service provider and service client. A dynamic
SLA is an SLA that generally changes from service period to service period,
to accommodate changes in provision of service.
14.5 Summary
The chapter started with the discussion of the drivers of cloud computing.
This was followed with the presentation of the concept of total cost of owner-
ship (TCO) and capital budgeting models. Costs for various models of cloud
service provisioning, namely, traditional internal IT, colocation, managed
services, and IaaS are considered for producing a comparison for assess-
ment. In the last part, we discuss aspects related to the Quality of Service
(QoS) and Service Level Agreement (SLA) for provisioning of cloud services.