What is a Saas anyway?

Question

I was reading this question What is cloud computing? and I was left wondering which line separates normal software from a Software as a Service (Saas).

After all, what is a Saas? And what are the main differences for a so-called normal software?

Answer 1

The two fundamental characteristics that differentiate a "Software as a Service" or on-demand, standard software, also called on premise, sane:

• it is centralized somewhere, usually a public cloud, but not necessarily.
• payment is made according to usage, or a periodic or per unit consumption value, such as time, transactions, handled amounts (employee numbers, certificates issued, etc.), or any other formula that makes sense.

In general you "buy" more than software, purchase infrastructure and complete support for what you need. No need to worry about hardware, network (to some extent), backup, maintenance, upgrade of the structure, update version, etc.

This is not always true. There are cases where only the monthly payment model or something like that already characterizes a Saas. But there are those who disagree of these cases.

In thesis it is a "pay to use". Pay according to demand and this would make the costs lower. In practice it is common for costs to be higher in the long run, but it depends somewhat on a number of factors.

It is common in web software, but nothing prevents the use of other forms. It is common to need a client, mobile or desktop to access the main software.

There are often gains from sharing the resources used (even people) among all users. But there’s a cost to trying to make everything work, for everyone, in the same environment. It can even be more complicated or charge a cost of lack of flexibility offered.

There are those who complain of lack of control, security and convenience. It is not easy to identify how much is a good solution.

It also sells the idea that it’s more predictable that way. In practice whenever the supplier has additional, unforeseen costs, he ends up passing it on to the customer. What can happen is to have fewer unforeseen costs from the supplier’s experience, but that is not guaranteed. Depending on the model adopted the cost can be much less predictable. And when it’s predictable, you end up charging the maximum you’d spend, the worst case, which is no advantage at all.

This is a way to improve the industry’s revenue, so much so that after it, the revenues of many companies in the industry, from cloud vendors, as well as the products that were previously sold without this model, including basic and specific software, exploded. If the industry is earning so much more then they have not offered less costs as promised. This occurred just when the current (old now) billing model was showing saturation. Some people will say that it is selling more software than before. I have not seen clear evidence that this is.

It’s a way for industry to fight piracy.

Anyway, it has advantages, but it also brings disadvantages and I will not list all because it is not the focus of the question.

He has brothers: Iaas, Paas, Daas, Mbaas, among others.

Answer 2

Using Azure as an example,

The image above tries to illustrate a bit the difference between each of the available cloud modes in Azure.

• Iaas - Infrastructure as a Service: The provider provides all the infrastructure for user configuration. The user has access to virtual machines and servers to be configured, allowing a greater control over the available environment. For the publication of a website, for example, the user must configure the application server, access ports, firewall, etc.
• Paas - Platform as a Service: The provider provides a template where the infrastructure is abstracted, and the user needs to worry only with the platform configuration. This model has certain limitations, but makes its configuration much easier and agile to perform, as the user does not need to worry about the infrastructure needed to run the application. For the publication of a website, for example, it is only necessary that you create a Paas with the necessary settings to run your site, and publish it through FTP, for example.
• Saas - Software as a Service: The provider provides both hardware (Infrastructure) and software (Platform) as a service. The user directly accesses the software here, without having the need to perform technical configurations for this. Examples are Office 365, calendars and email services.

And what are the main differences for so-called normal software?

When we talk about Saas and talk about cloud, it is important that the software complies with the characteristics that define a cloud technology. This is the main difference between a software as a service and a so-called normal software.

By way of information, it follows below some characteristics considered essential for a technology to be considered cloud.

• On-demand self-service: The user must have the ability to provide resources for the cloud without the need for human interaction for this.
• Broad network access: Basically, the provider must provide the service in a way that is possible to access it through the internet.
• Rapid elasticity: The provider should make available to the consumer the possibility to increase or decrease his resources quickly in certain scenarios. You can think of elasticity as a Feature so that the user doesn’t spend resources unnecessarily, consequently paying more for it. A shopping website can use the service of quick elasticity during a promotion, such as black Friday, for example.
• Measured Services: The provider must provide a way to measure the resources used by the service, so that it is possible to monitor and control it, thus building better transparency between the consumer and the provider.