Public, Private, Hybrid—The Little Cloud ABC

28.06.2019

Topic: Cloud

When we think of digitalization, a landscape without the cloud is unimaginable. The cloud has been prominent in the headlines for years, and many companies have firmly anchored cloud strategy in their corporate strategy.

Fair to cloudy—does the cloud stand the test of everyday life?

But what exactly is this cloud? "Oh, I know what cloud is. It's like OneDrive, Dropbox and Netflix!" When IT architects and IT experts hear this, they smile. And rightly so: cloud computing is a lot more than just storage media and online streaming services.

It must be acknowledged that the cloud is already firmly established in private use. The advantages are obvious: For a small monthly fee, customers can exchange holiday photos quickly and easily, share them with family members, and store and play music without overtaxing the memory of their smartphones. Thanks to streaming services such as Amazon Prime, Netflix, and Maxdome, even films can be played from anywhere on all kinds of end devices, with costs based on actual consumption.

And how does this cloud technology fit into everyday business life? The purpose of this article is to provide a few insights into cloud computing and to clarify the different deployment and service models. It might be of aid to users, decision makers and interested parties in making an assessment as to which cloud model might be the best fit for them.

Prospects for businesses—the cloud models in use

Cloud computing has become an established part of everyday business life and is gaining in significance. An IDC study indicates that in 2017 already more than 80 percent of companies were already using cloud services and cloud technologies, or at least were looking into them.

The application scenarios are manifold. Companies use service models such as SaaS, PaaS, and IaaS for use of application software, among other things, as well as to better scale their consumption and react flexibly to changing market requirements. Different cloud deployment models are also conceivable, ranging from public to private or hybrid. In the following, we'll probe these concepts and look at how they might best be classified.

Delineating the idea of the cloud

Before you decide on a cloud solution and integrate it into your corporate strategy, it's advisable to clarify what's actually meant by the many different terms that come to mind in this context. Admittedly, it's not easy to classify the different terms and cloud models or to bring a correct method of classification to bear in making a decision.

Though many companies see their next move as that of migrating to the cloud, they often do not know which concrete steps will get them there. The market offers an abundance of models and solutions, and there seem to be an individual solution for each kind of requirement.

Before going into what the different deployment and service models really offer in the cloud environment, let's pose the seemingly simple question: What is cloud computing really? The fact is that it's difficult to find a common definition for the term cloud computing. Though the definitions used in many publications and lectures often share common terminology, they tend towards great variety.

In the traditional on-premises model, companies operate and manage their IT locally on their own servers, possibly even across entire data centers. This is where cloud computing comes in and starts to optimize and accelerate the traditional process. When using the term cloud computing, we are referring to a model in which IT infrastructures and IT services—think computing power, storage space, or even application software—are no longer purchased, no longer locally implemented, and no longer locally operated by a user company itself; rather, they are provided as a service "on the Internet" by a provider that scales according to customer requirements.

The service models: Iaas, PaaS and SaaS

With our definition of cloud computing as a basis, let's move on in tightening up our understanding of the cloud. Basically, cloud computing can be categorized into three different service models, namely Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).

Infrastructure as a Service (IaaS) refers to the demand-based use of IT resources such as server, storage, and network capacity. Customers rent infrastructure from a provider as a flexible service and don't have to worry about implementation and maintenance. They can adapt their requirements to actual consumption in order to better cushion any peak loads and overcapacities. "Infrastructure as a service" allows you to rent computing power and RAM from a provider and then to run an operating system with your own applications.

Platform as a Service (PaaS) is a service model in which a web application development provider offers comprehensive development and deployment environments in the cloud. Customers have access to the resources they need to deploy applications and cloud-based apps. They can also use the development environment for application deployment at relatively low cost.

Software as a Service (SaaS) is one of the most popular service models in cloud computing. A provider offers software applications as a service via the internet. With the SaaS model, use of applications is flexible and device-independent. The provider of the software application operates the IT infrastructure necessary for the applications and is responsible for their availability and administration by performing software maintenance and updates. The customer pays by volume and duration of use, in a model that is generally priced on a monthly basis.

The deployment models: public, private and hybrid

In addition to the three service models described above, there is more differentiation with regards to the deployment models. First and foremost, these deployment models include the public cloud, the private cloud, and the hybrid cloud.

A public cloud is what its name suggests—a public cloud offered by a provider with general accessibility. The cloud services of a public cloud—applications, platforms, and even IT infrastructure—are openly accessible to a large number of users via the internet. The offerings of a public cloud may be partly free of charge or billed according to the actual use. They offer scalability according to preference and consumption.

One speaks of a private cloud when the entire cloud infrastructure is operated for a single company. The cloud environment may be run in the company's own data center or hosted in a provider's. Another way of using the private cloud is for the company to operate and manage it on its own, or to outsource this service to a third-party provider or hosting provider.

A common characterization of the hybrid cloud is that it combines the best of the two cloud worlds "Public Cloud" and "Private Cloud." However, it's more, too: Some services can remain on-premises, i.e., locally in the company, with others being relocated to the cloud. And this indeed is the most common real-case scenario. As a mixed form, the hybrid cloud marries the advantages of the different provisioning models. With the hybrid option, customers can store their business-critical data locally and transfer their automated and standardized processes to the cloud.

The cloud: More than just a storage medium

The cloud offers a profusion of options, most of which adapt well to the needs of companies. Therefore, as with every new advance in technology, it is important for companies to inform themselves extensively on the cloud and all associated new trends and technologies, and to look at different approaches, models and scenarios with a discerning eye. What is most important for companies is to find the model that best suits their needs. This way they will be able to exhaust its value long-term.

If this article has aroused your interest and you would like to learn more about cloud solutions in the area of workflow management systems, take a look at our white paper "Harnessing the Potential of Digitalization: The Added Value of a Cloud-Based Workflow Management System", which you can download here.

*Source: IDC – Analyze the Future. Cloud Trends in Deutschland 2018 idc.de/de/research/multi-client-projekte/multi-cloud-in-deutschland-2018-management-architektur-provisionierung-providerauswahl, accessed in April 2019.