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Cloud computing

IaaS vs PaaS vs SaaS: the advantages and which model to choose

Cloud computing has revolutionized information technology, traditionally tied to the ownership of hardware and software resources, which are now increasingly being made available on the basis of service-based models, based on virtualization technologies.
Cloud availability is predominantly based on “as a service” solutions, particularly with regard to three main models: IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (Software as a Service).
Let’s take a look at what IaaS, PaaS, and SaaS consist of, what the main differences are for the various categories of users, and how you can navigate the sea of solutions that the cloud market currently presents.

What are the differences between IaaS, PaaS, and SaaS?

The three main cloud service models differ in what they make available to end users.
As the name suggests, IaaS offers infrastructure at a basic level, from which companies can deploy and customize their IT systems.
PaaS offers environments that developers can use to create and manage their custom applications in an agile way, thanks to API interfaces.
PaaS, as we will see, makes extensive use of containers and other technologies specifically designed for microservice architecture-based development.
Finally, SaaS consists of native cloud software that users can use remotely, through simple access via a web browser or mobile app, without necessarily having to download and update anything locally.
IaaS, PaaS and SaaS thus constitute different solutions to equally varied needs.
What they have in common is that a number of endowments and services that were traditionally implemented in-house by the corporate IT department are now made available by cloud providers.
Let’s look in more detail at what they consist of, what the main pros and cons are, what users’ responsibilities are, and in what areas of business they are predominantly used.

IaaS

An acronym for Infrastructure as a Service, IaaS allows organizations not to necessarily have to have a proprietary data center, being able to take advantage of the hardware-software infrastructure directly in the cloud, managing and using it through the Internet.
In fact, cloud providers secure hardware resources through IT system virtualization technologies, which enable consolidation of physical resources by making IT configurations made available to end customers scalable.
The figurehead, on the enterprise side, is the IT administrator (sys admin) who decides which resources to order from IaaS providers and agrees to install and configure all the operating systems and applications needed to meet business needs.
In other words, IaaS service vendors make available through the Internet all the computing, storage and networking components that traditionally populated, and in many ways still populate, data centers set up within the corporate perimeter.
As far as virtualization technology is concerned, we are at the hypervisor level, which allows for maximum capacity at the level of customization of the IT systems that the organization intends to deploy.

The advantages

The main advantages of the IaaS model relate to:

  • Costs: IaaS enables you to have the IT infrastructure you need under a “pay-as-you-go” model whereby you pay only in relation to what is actually used to meet your workloads.
    The burden of owning IT systems is fully delegated to cloud providers, saving organizations from having to purchase and configure an in-house data center from scratch.
    This model is generally more cost-effective, as cloud providers are able to be particularly competitive by being able to take advantage of the economies of scale that are generated from offering this kind of resource to many companies.
  • Ease of management: resources from IaaS providers are made available through simple control panels, which make it easy to manage every aspect of ordered configurations, starting with their initial configuration.
  • Scalability: systems engineers can easily manage every aspect of the IT infrastructure and provide for increasing or decreasing the purchased resources according to the actual needs required by workloads.
    In the traditional situation, such a condition would inevitably have involved the purchase of new resources to be installed at the data center, often the cause of unforeseen expenses, or the presence of unused resources, also the cause of obvious diseconomies.

However, the IaaS model also has some critical issues, which need to be budgeted for and managed as appropriate:

  • Service availability: when a company chooses an IaaS service, control of the IT infrastructure is no longer within its purview, as resources are physically available at the cloud providers’ data centers.
    Although these provide, even contractually, high reliability guarantees, in the event of a widespread downtime, IT resilience could be put to the test due to the inability of the company using an IaaS service to intervene directly on the problem.
  • Security: in an IaaS environment, it is clear that away is co-responsibility for data storage and processing, as companies effectively delegate control of IT system security to cloud providers.
    This constitutes one reason why, in certain regulatory or contractual contexts, data cannot leave corporate data centers.

When to use it

The Infrastructure as a Service model is frequently used in the following cases:

  • Software development: IaaS constitutes an optimal choice when one intends to configure the entire development environment from scratch, relying only on the IT systems that are tasked with running it.
    With IaaS, system builders can easily manage every aspect of the IT infrastructure and provide for augmenting or decreasing the purchased resources according to the actual needs required by the workloads, starting with the application development and testing environments.
  • Web hosting: cloud providers make available IaaS environments designed specifically to make websites available, which allows companies a number of advantages, both technical and economic, over using traditional hosting solutions.

PaaS

An acronym for Platform as a Service, PaaS is a cloud deployment model designed especially for application development, using the Internet to access the platform and its tools.
In other words, PaaS can be subjected to a framework that developers use to create custom applications, based on microservice architecture, in which different components are created independently and communicate with each other through APIs.
At the liability level, the cloud provider maintains and manages the main IT components (servers, storage, and networking), operating systems, and development environments (containers, etc.) by updating all the tools used by developers to create custom applications.
As far as virtualization technology is concerned, this takes place at the operating system level, so the target users, in this case the developers, do not have to worry about what concerns the underlying infrastructure, since the resources are scaled automatically to adapt to the needs of the workloads that lie ahead.
In some ways, it is possible to imagine PaaS as a simplified version of IaaS, where in addition to the infrastructure, the software platform needed to develop the custom applications is also provided, which in turn are made available over the Internet through the SaaS (Software as a Service) model.

The advantages

As in the case of IaaS, the Platform as a Service model has significant advantages for those who intend to make use of it in an informed manner.

  • Reduced time to market: PaaS makes available ready-to-use platforms with a set of essential tools, updated with the latest technologies available on the market.
    Development teams can then use version management tools that can easily manage the work of individual programmers, as well as tools that can automate much of the procedures involved in testing and releasing the applications themselves.
    Creating new software also becomes faster thanks to the collaboration tools available on PaaS platforms, which enable teams to work together regardless of their physical location.
  • PaaS platforms provide compute and storage infrastructures, along with text editing, version management, compiling and testing services that help developers efficiently build new software.
    They also help development teams work together, regardless of wherever they are physically located.
  • Ease of use: as in the case of IaaS, the burden of managing the service is entirely on the cloud provider, who is responsible for making available, in addition to the infrastructure, all the technologies used in modern software development, such as containers and Kubernetes.
    In any case, development teams need only a web browser to access PaaS.
  • Scalability: PaaS allows developers the ability to vary the availability of the resources needed for software development through simple, Web-accessible control interfaces.
    The trend is to make the IT infrastructure as transparent as possible, a concept emphasized especially in the case of serverless interfaces.

Again, there is no shortage of critical issues, which should be remedied through proper planning:

  • Visibility in the multicloud: The cloud market leads organizations to use many services, delivered by multiple vendors.
    To cite a practical and recurring example, achieving a good level of visibility in relation to a very large number of containers at PaaS from various vendors involves the use of ad hoc solutions and, in general, a solid cloud management strategy.
  • Lock-in: When a development team starts using a PaaS platform, it starts working on partly proprietary technologies, which makes it complex to disengage in case significant scenario changes occur, such as service cost increases or unilateral contract changes.
    Migrating applications from one PaaS to another is indeed not an elementary task.

When to use it

PaaS is frequently used in many areas involving modern applications based on microservice architecture.
Among these we can mention:

  • API development: for all intents and purposes, PaaS is the natural habitat for modern application development.
    With PaaS, developers can find the development environment best suited for their applications to safely create, run, and manage the APIs and components of the microservices architecture on which modern software is based.
  • Business Analytics (Big Data) and IoT: Modern data analytics applications, based on artificial intelligence technologies, are being developed on PaaS platforms.
    Other emerging technologies frequently find their applications in PaaS, as in the case of the Internet of Things (IoT).

SaaS

An acronym for Software as a Service, SaaS is the model that makes applications available in the cloud through the Internet, which allows end users to access them through a simple Web browser, without having to install anything specific locally.
Unlike in the traditional IT context, companies no longer need to manage the software in terms of installation and update processes, as the provider always guarantees the end user the most up-to-date version.
In other words, the SaaS provider deals end-to-end with the IT aspects necessary for large-scale software deployment, addressing, in addition to initial development, all phases of the life cycle, of which maintenance and support are part.

The advantages

The most significant benefits associated with using cloud-native software under the SaaS service model are as follows:

  • Ease of use and management: the end user is relieved of any burden of configuring and managing the software and can finally think only of using it to do his or her work, in his or her profession, education, and leisure.
    In the enterprise context, the corporate IT department is relieved of the complex and onerous task of installing, maintaining, and updating the software, as well as configuring it and making it timely available to end users.
  • Scalability: as in the case of IaaS and PaaS, the SaaS model also takes advantage of the proverbial scalability of cloud computing to facilitate access and management of software over the Internet.
    The IT department can add or subtract new users to the deployed services at any time, without having to purchase new permanent licenses, as is the case in the traditional IT context.

Among the main critical issues related to SaaS it is worth considering:

  • Integration of existing systems: cloud-native software is based on the microservice architecture, which involves components communicating with each other through API interfaces.
    However, it is not so elementary to make the APIs of new applications communicate with existing systems, especially if they are based on traditional development logic.
    In this case, the exchange of data between SaaS applications and enterprise systems could be problematic if the developer of the latter does not prepare an adequate level of openness in this regard.
  • Limited control: in the case of SaaS, the level of responsibility hangs almost entirely on the cloud provider, so business customers may run into problems related to the limited possibility of customization should singular needs arise.
    It is also not possible to have any control toward the IT infrastructure that the cloud provider use to deliver SaaS services.

When to use it

SaaS is used in all circumstances involving applications congenial to the service model on which it is based: e-mail, CRM, ERP, FinOps, HR, sales management, billing, collaboration, etc. SaaS offers new business opportunities to ISVs (Independent Software Vendors) who can deploy their software in the cloud taking advantage of all the benefits of pay-per-use logic to increase their user base.

Which model to choose

The three aforementioned service models are available in both pay-per-use and subscription-based modes, as well as various hybridization options, allowing each organization to find the ideal solution to meet its business needs based on its budget.
The choice between IaaS, PaaS and SaaS depends on what the organization actually needs when it comes to evaluating an IT environment.
With this in mind, if the company is looking for a productivity tool, it will be geared toward SaaS, whereas if it needs to develop and make an application available, it may opt for Paas or IaaS.
In general, when needs are related to pure operations and there is not a high need for customization and integration with existing systems, SaaS is a preferred area, to be productive almost immediately.
In contrast, a more structured and resourced company very often needs applications that are customized and able to integrate quite deeply with existing systems, as well as with the workflows in place.
These conditions lead to a preference for ad hoc application development and therefore the adoption of the PaaS or IaaS model, which compared to SaaS provide a significantly higher level of control.
If you would like to pursue your evaluations with us, please contact us and we will be at your disposal to study the best evolution for your IT