Cloud Computing Service Models – IaaS, PaaS & SaaS and their Key differences

Cloud computing is the practice of using a network of different servers that host, store, manage and process data online — in “the cloud”.

Cloud computing is classified into three categories – Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS).

The services automatically scale as demand increases. By moving business operations and data to the cloud, organizations can bypass time-consuming traditional IT processes and enjoy immediate scalability and flexibility, along with significant cost reductions and support for business growth.

• Infrastructure as a Service (IaaS):

The lowest level is infrastructure-as-a-service (IaaS). This is where pre-configured hardware is provided via a virtualized interface. There is no high level infrastructure software provided, this must be provided by the buyer embedded with their own virtual applications. Some vendors like Oracle will provide operating system also as part of their IaaS service but not all.

IaaS includes servers, memory, storage, network and data center. This service is similar to the company data center, but it is provided by Vendor.

Vendor is responsible for Virtualization, Storage, Servers, Networking and Operating System. Customer is responsible for Applications, Data and middleware.

Oracle Cloud Infrastructure (OCI), Microsoft Azure, Amazon Web Services (AWS) are some of the IaaS providers. Users don’t see any difference for moving the applications from on-premises to IaaS. Oracle EBS applications can be run on the Cloud platform using IaaS model.

It helps you to get out of the data center business and taking advantage of modern infrastructure. While IaaS customers are usually responsible for installing and maintaining the operating system, databases, security components, and applications.

• Platform as a Service (PaaS):

It refers to cloud-based platform services that provide developers with a framework they can use to build custom applications upon.

Platform as a service (PaaS) goes a stage further and includes the operating environment included the operating system and software tools (database/middleware/development tools).PaaS suits organizations that are committed to a given development environment for a given application but like the idea of someone else maintaining the deployment platform for them.

PaaS provides let developers build custom applications online without having to deal with data serving, storage, and management.

Customer is responsible for Applications & Data. Vendor is responsible for Runtime, middleware, O/S, Virtualization, Storage, Servers and Networking.

• Software as a Service (SaaS):

It refers to cloud-based software that is hosted online by a company and is available for purchase on a subscription basis and is delivered via the internet.

SaaS offers fully functional applications on-demand to provide specific services such as CRM, ERP, email management, web conferencing and an increasingly wide range of other applications.

• Sales Force, ERP Cloud Applications (Oracle SCM/Financial Cloud), Office 365 and Google Docs etc., are SaaS applications
• It is subscription model. Pay as you go
• No customizations. Use PaaS for customizations and the PaaS application is integrated with SaaS application using web services.
• Single code set for all customers
• Professionally managed by Vendor
• Cloud native applications
• Customers don’t have control on patching/upgrades
• SaaS has become a common delivery model for many business applications including ERP softwares.

IaaS gives users automated and scalable environments with extreme flexibility and control, while PaaS provides a framework for quickly developing and deploying applications by automating infrastructure provisioning and management. Eliminating the need to install and run programs on individual devices, SaaS makes applications available through the internet.

Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS) provide the most immediate benefits.

Oracle is the service provider for IaaS, PaaS and SaaS. Oracle uses 2nd generation Oracle Cloud Infrastructure for the IaaS and PaaS deployments. Oracle customers who already own Oracle E-Business Suite license may use the Oracle Cloud to host EBS applications. Lot of customers are moving their EBS applications from on-premises to Oracle OCI.

Oracle has no plans to offer Oracle E-Business Suite as a SaaS solution, But Oracle re-developed the ERP applications for SaaS solution and it is called Oracle Cloud Applications/Fusion Applications(ERP Cloud, SCM Cloud, CX Cloud and HCM Cloud).