IaaS PaaS SaaS – Cloud Service Models
An IBM perspective: IaaS vs. PaaS vs. SaaS
In the traditional method of consuming services or resources, the owner of the infrastructure is responsible for managing every piece of hardware and software he or she uses. Normally, it takes some time for a user to access a new resource, but it can be configured exactly as needed.
Traditional infrastructure is often related to legacy core applications (tied to older technologies perhaps) that cannot be easily migrated to cloud paradigms. Elasticity, standardization, and other clear cloud advantages are not sufficient reasons to migrate. In other cases, rigid security and country regulations sometimes force to have data located nearby and/or under total management control.
Infrastructure as a Service (IaaS)
The management responsibility for the company starts with the operating system layer and the provider ensures the availability and reliability of the infrastructure provided.
Several use cases can benefit from this pattern. Companies that lack an owned data center look to IaaS as a quick, cheap infrastructure for their business initiatives that can be expanded or terminated as needed. Traditional companies that need compute power to run variable workloads with less capital expenditure are perfect examples of IaaS adoption. In both cases, companies will only pay for the services they use.
Platform as a Service (PaaS)
Development companies and/or factories that want to implement agile methodologies are the most suited for PaaS. PaaS providers publish many services that can be consumed inside applications. Those services will be always available and up-to-date. PaaS provides a very simple way to test and prototype new applications. It can save money when developing new services and applications. Applications can be released more quickly than usual to get user feedback. The API economy is the new paradigm in development, and the cloud provides the perfect platform for its implementation.
Software as a Service (SaaS)
Today, SaaS patterns are generally accepted by many companies that want to benefit from application usage without the need to maintain and update infrastructure and components. Mail, ERP, collaboration, and office apps are the most accepted SaaS solutions. The flexibility and elasticity of the SaaS model are great benefits.
There is no one size fits all for cloud adoption. Companies should consider their own cost and benefit equation and then decide on the best model. Each application and process needed is a workload, and a deep workload assessment is normally performed by companies that have decided to move to the cloud .