In our previous articles What is Cloud Computing? we covered the principal definition and characteristics of true cloud services. However those characteristics are not enough in themselves to fully describe cloud computing. The National Institute of Standards and Technology (NIST) adds four deployment and three service models to complete the picture.
Cloud computing is essentially an on-demand service based approach to providing computing and information systems resources. It essentially turns IT provision into a utility, similar to telephone or energy, which is paid for on the basis of the services used. It presupposes a service metered in some way.
Essentially services fall into three broad categories and, again, like the characteristics they are not unique to cloud services. However the service based models described are most closely associated with the supply of cloud services; it has only been with the advent of the cloud that they have become a mainstream approach.
IaaS is essentially the provision of the hardware (servers, storage, network connectivity, …) that is usually a capital expenditure with traditional hosting models. The consumer can then run their choice of operating systems, databases and the applications that are deployed out to the end users. The cloud hosting service supplier maintains the hardware, including technology refreshes, and other components of the infrastructure while the consumer looks after the operating systems and applications and their change management. In the simplest case this might be a cloud server with flexibility as described in the previous article on characteristics.
Moving up a level or two in the technology stack PaaS takes the IaaS model and then adds provision of and management of the systems software such as operating system, databases, networking and other tools that are provided to the consumer, perhaps for system development. In this case the consumers’ management responsibility is entirely concerned with the provisioning of user applications and any development of such systems if they are not off the shelf packages.
With SaaS the consumer is simply a user of business systems, such as finance, Customer Relationship Management CRM), Data Visualisation or Enterprise Resource Planning (ERP), and has minimal involvement with the provision (once selected) of the business facing applications. The consumer may have a role in configuration of the end-user function of the chosen software but the maintenance of the software such as applying updates to new versions usually lies with the SaaS supplier.
In all three models the consumer organisation will have responsibility for the local user domain with its, and end-user’s, connection to the cloud service provider. This will include the security and provision of network connectivity and the devices used to access the SaaS applications.
In addition to the three services the UK government adds a fourth component, Professional Cloud Services to its G-cloud catalogue which allows public sector bodies to buy cloud services off the shelf without complex procurement procedures. While not strictly part of the cloud model they form an important element for those making the move to a cloud approach from tradition IT service models. They provide a means of achieving a faster transition or start up for organisations switching their computing to the cloud. The G-cloud catalogue is published and could form a starting point for anybody researching what is available; it should be remembered that it is not complete in that there are major suppliers not represented on the catalogue.
Professional cloud services are essentially the people and skill based resources needed to make the move to the cloud. These can cover everybody from business analysts and consultants to technical staff familiar with the new approach to computing technology. Their use should be on achieving a rapid implementation of the cloud model with a transfer of knowledge and understanding to allow client staff to take it forward into business as usual operations.
As with any new technology and the cloud generally many services offered in this way are in fact traditional services rebadged as the new approach. They have been “cloudwashed”; old products and services relabelled as the latest thing, again. The purchaser of cloud services needs to be careful of what they are buying; if you are not confident of your technological understanding seek independent advice from sources that are not tied to IT suppliers.
In our next article we will cover the deployment models for cloud computing. It is the aspect that has the most layers of complexity and can be used to create fear, uncertainty and doubt. As a result these are perhaps the least well understood aspects so we will focus on explaining them in practical rather than theoretical terms. In fact, for most organisations, especially SMEs, the picture need not be as complex and confusing as it is often painted.