Cloudware Operations and Management - Guide to Cloud Computing for Business and Technology Managers - page 383

and privacy of data, and geographical location of data are met.
Data availability is important for the user's business, and, thus, it is
important to review the contingency plan that the service provider
has in the event of a data center/service failure (either own or of the
service provider's).
• SLA management : The service provider's readiness in SLA to provide
some transparency into the vendor's operations in the areas of audits
and compliances and its flexibility to meet SLA requirements includ-
ing penalties in case of noncompliance is a key deciding factor as it
impacts the fulfillment of many other requirements. The flexibility
of the SLA to reflect the service user's business requirement, includ-
ing a match to inputted translated business metric of the cloud ser-
vice user, must be reviewed.
• Contingency and disaster recovery plans : It is important to review the
contingency and disaster recovery plans that a service provider
provides.
• Features of services provided : Ultimately, the distinguishing factor
among different service providers may be the features of the service
they offer including the ability to find the best services for the user
based on the user's business and its businesses location.
• Service provider references : A review of the references provided by
the service provider is a necessary step. This should ideally include
the possibility to communicate with actual users of the services
of the service provider.
18.6 Service-Level Agreements (SLAs)
Most customers are willing to move their own premise setup to a hosted
environment only if their data are kept securely and privately as well as
nonfunctional properties such as availability or performance are guaran-
teed. Providing cloud services to customers requires not only managing
the resources in a cost-efficient way but also running these services in cer-
tain quality satisfying the needs of the customers. The quality of delivered
services is usually formally defined in an agreement between the provider
and the customer, which is called service-level agreement (SLA). In the fol-
lowing sections, we introduce the basic ideas of such agreements from the
technical perspective of cloud computing and give an overview on tech-
niques to achieve the technical goals of service quality.
Service-level agreements define the common understanding about ser-
vices, guarantees, and responsibilities. They consist of two parts: