It seems more or less accepted that SAAS is a part of cloud. There are numerous references throughout the web that is defending this position and even in a lot of posts on cloud can see the software as a service as part of cloud services.

But is it really SaaS Cloud ?

Recall that the differential factor of cloud is one that allows access to the resource / s hardware and software almost immediately and get rid of them in the same way. It is precisely this characteristic that distinguishes it from usual hosting and ASP .

High above, technically to be able to get the differential factor, the cloud relies on the multitenancy as hardware and software architecture for allocating the resource and the concept of scalability to meet increasing demand or decreasing the customer. And all this quickly.

From the customer point of view who is using a SAAS , is it an accessible resource away? That is, what is saas cloud? Yes Most saas have the possibility to create your room to use the online application, whether or freemium model with free access for 30 days or pay, and therefore meets the definition of cloud fast access to software and possibility to upgrade or remove users immediately (scalability).

Now from the standpoint of the provider, how many saas have mechanisms to “ensure” immediate access to the software? Do you have technology to offer? I’m afraid that most do not have it. Have multitenancy but not technology that ensures continuity of service (fast escalation, maintenance of current users, etc..) before a flood of new users who want to use the application.

And then, is the saas cloud computing or not? Being purists for saas should or have technology in their systems to meet demand given or at least rely on a service paas or IaaS that can provide coverage to the problem. But few of “saas have this problem” For fingers counted. The vast majority have control of growth (decline) of users more or less predictable and gives them time to size their systems to cover this problem. Some talk about it, if you need quick access to cloud computing resource is what you need, and this also applies to the SAAS .

And now back to the beginning of the text changes the word saas by paas and little else, and the reasoning is equally valid for the country. Although a paas without a rapid escalation mechanisms is much more difficult to find.