Page 658 - Cloud computing: From paradigm to operation

3 XaaS

Appendix I

Use case of Infrastructure as a Service
(This appendix does not form an integral part of this Recommendation.)

This appendix includes IaaS related use cases including an infrastructure level use case, and computing ,
storage and network service use cases.

I.1 Use case template

The use cases developed in this appendix should adopt the following unified format for better readability and
convenient material organization.

Use case

Name Title of the use case
Abstract Description for overview and feature of the use case
Roles Roles relating to or appearing in the use case

Figure Figure to present the use case (UML-like diagram is suggested for clarifying relations
between roles but it is not mandatory)
Pre-conditions The pre-conditions represent the necessary conditions or use cases that should be achieved
(optional) before starting to describe the use case. As dependency may exist among different use
cases, such a description can help others to understand relation among the use cases.
Post-conditions Similar to that for pre-conditions, the post-conditions describe conditions or use cases that
(optional) will be carried out after the termination of currently describing use case. Such an inter-use
case dependency clarification improves the collaboration of use cases.
Description Description introduces the detail information of the use case, such as the processes or
major steps. It is helpful for the reader to better understand it.

Requirements Requirements (titles) derived from the use case. For example;
– Large-scale migration: A CSP in the inter-cloud federation is required to be able to
guarantee continuity of all the services in this CSP by large-scale service migration with
minimum impact during a desired period. It is recommended to consider priority of
services when migrating.

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