Scotland's Digital Future: Scottish public sector cloud computing guidance

Definitions

There is a lot of confusion and misunderstanding of what cloud computing means to individuals and organisations. To enable greater understanding and consistency in the language used, the Scottish public sector will adopt the US Government's National Institute of Standards and Technology (NIST) definition of Cloud Computing.

"Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model is composed of five essential characteristics, three service models, and four deployment models."

Five Essential Characteristics

• On-demand selfservice
  
• Broad network access
  
• Resource pooling
  
• Rapid elasticity
  
• Measured service

Three Service Models

• Software as a Service ( SaaS)
• Platform as a Service ( PaaS)
• Infrastructure as a Service ( IaaS).

Four Deployment Models

• Private cloud
• Community cloud
• Public cloud
• Hybrid cloud

The definitions, described in more detail in Annex 1, are intended to help those developing policy or the adoption of solutions in cloud computing to develop a consistent framework of understanding, with common frames of reference and simple taxonomies. These definitions are not intended to prescribe or constrain any particular method of deployment, service delivery, or business operation.