Cloud computing seems to be all the rage at the moment. There are many good reasons for this and others that will just prove to be hype over time. However there is not doubt that this could be as disruptive to the software industry as iTunes, Napster and others are proving to the music industry.
In this article we will outline the 3 key categories of cloud computing – all ending in “aaS” (which stands for “as a Service”). This will give us a good starting point from which to discuss the larger and more radical points alluded to above later.
By the way the term “cloud” originates from the cloud symbol used by techies to represent the Internet on the majority of diagrams.
CaaS
Cleaning as a Service.
No prizes for guessing we have made this up (there are really 3 types, not 4). But it should help demonstrate the service principle without any IT jargon. For those who want to dive straight in, jargon and all, then skip to SaaS below.
Imagine a world where you do your own cleaning, you bought the vacuum cleaner and pay for its repairs and replacement, you buy the bags, cloths and cleaning fluids and other items as you go along.
You decide there must be a better way, you discover the kids are pretty keen on this and want the pocket money so you pay them to use your vacuum cleaner.
You discover they are not so good at the job (more interested in playing with the gadgets than the business of cleaning) and keep forgetting bits.
So you decide to outsource to a cleaner but find you are still providing all the tools and consumables and probably find yourself feeling embarrassed and doing cleaning before they arrive.
Then a salesman turns up and you are persuaded to buy a robotic vacuum cleaner that does the cleaning by itself. But when it breaks down it’s a pain to fix. Then somebody offers you a self-healing upgrade so the vacuum repairs itself (they claim) and it’s just getting too confusing.
And so it goes on until you find somebody offering CaaS – you just pay them a monthly amount and they do all the cleaning. provide all the equipment, maintenance and consumables and, heck, they even bring their own electricity and water.
You just order the service you need. The Spring Cleaning service please, the Window Cleaning Service please….
And so it is with cloud computing – you are just buying a service and letting somebody else worry about all the rest.
SaaS
Software as a Service.
Here you are paying for a service that covers everything needed to provide the software (the servers, internet connection, maintenance, licences etc. etc.) Salesforce.com is a pioneer in this field and a classic example of SaaS. A typical feature of a SaaS offering is that you pay a fee (hopefully small) per user often starting with a small number (e.g. 5 users) at a price you could never match if you were to build and buy your own servers and run a deployment project to get it all live.
PaaS
Platform as a Service.
Here you are paying for a service that covers everything to provide the platform to run your service (servers, operating systems, internet connection etc.) but not the software itself or at least the development effort to create the final software.
In this case it is often about software development, you have the developers but don’t worry about providing everything else they need to do the job in house. Often this services includes presenting the software to customers via a website when it is live, so you really are just doing the design, development and test bit in the middle.
A good example of this is Google AppEngine. You start out small, but if your application suddenly becomes massively popular you just buy more storage and bandwidth as you need it rather than panicking and running to your hardware supplier.
IaaS
Infrastructure as a Service.
Here you are paying for a service that covers the infrastructure (often referred to as the “tin”). So all the servers, storage, networking etc. are part of the service but none of the software.
A good simple example is Amazon ECS which provides on demand servers.
Some simpler services are just about on demand storage.
Key Features
So what things really unite all of these offerings as cloud services:
- On demand – you buy what you need, when you need it
- Elastic – you take as much or as little as you need
- Fully managed – somebody else is looking after it for you
Sometimes people use the term “utility computing” imagining that you buy computing much as you buy electricity or water from your utility company.
And to top it all we haven’t even got the space to look at the types of cloud (e.g. private, public, community or hybrid). Perhaps another day.








Why is solving problems never as easy as it seems? We won’t attempt to provide a complete answer in a single blog, but we hope to share a very important idea to help in the process.


Recent Comments