Cloud computing and Software as a Service Overview
Software as a Service (SAAS)
Software as a Service
SAAS sometimes referred to as "software on demand," is software
that is deployed over the internet.
Software deployed as a hosted service and accessed over the
Internet as opposed to: “on premise”.
With SaaS, a provider licenses an application to customers either
as a service on demand, through a subscription, in a "pay-as-yougo" model, or at no charge when there is opportunity to generate
revenue from streams other than the user, such as from
advertisement or user list sales.
Examples of free SaaS applications include large players such as
Gmail and Google Docs.
Other examples: Sales Force (CRM)
Accessible from anywhere with an internet connection.
No local server installation.
Pay per use or subscription based payment methods.
System maintenance (backup, updates, security, etc) often included
Activities managed from central locations rather than at each
customer's site, enabling customers to access applications
remotely via the Web.
Centralized feature updating, which obviates the need for endusers to download patches and upgrades.
Capital expenditure is reduced by not having to purchase servers
or full copies of software.
Faster implementation. In some cases the customer can deploy
SaaS more quickly as no local installation is required.
It may remove a non-core activity (deployment and support of the
software and its associated infrastructure) freeing up time to focus
on core business activities.
Reduced need to predict scale of demand and infrastructure
investment up front.
Possible improvements to reliability if the SaaS provider's
infrastructure is more redundant or has higher availability than the
user would otherwise have.
Fewer up-front costs, SaaS is often easier to discontinue or
substitute, reducing switching costs.
SaaS applications provide the opportunity to implement pricing
models that establish and maintain recurring revenue streams.
Most SaaS vendors charge a monthly hosting or subscription fee.
Opportunities also exist to charge per transaction, event, or other
unit of value. These alternative pricing models exist because
customers "lease" the software from the vendors and the vendors
can view all transactional activity.
Subscription based (monthly fee per seat) .
Transaction based pricing (profit sharing).
Ad-based revenue (e.g. pay per click).
◦ Security concerns. The primary concern stems from the fact
that the corporate data is being stored, and controlled, by third
◦ Using SaaS can cause as much harm as proprietary software,
since users can't modify the particular software they use, thus,
they can't control their own computing.
◦ Service cost, integration difficulty, and technical requirements.
◦ Market reached $6.3B in 2006; still a small fraction of the over
$300B licensed software industry.
Application Service Provider (ASP)
An application service provider (ASP) is a business that provides
computer-based services (such as customer relationship management)
to customers using a standard protocol such as HTTP.
Build. Software is
developed by the
vendor form the
ASPs often depend on
may be implemented
at SAAS datacenter
and made available to
all the users.
Utility Computing is the packaging of computing resources, such as
computation, storage and services, as a metered service similar to
a traditional public utility (such as electricity, water, natural gas,
or telephone network).
This model has the advantage of a low or no initial cost to acquire
computer resources; instead, computational resources are
essentially rented - turning what was previously a need to purchase
products (hardware, software and network bandwidth) into a
This new utility became the foundation of the shift to "On
Demand" computing, Software as a Service and Cloud
Computing models that further propagated the idea of computing,
application and network as a service.
Cloud computing is location-independent computing, whereby
shared servers provide resources, software, and data to computers
and other devices on demand, as with the electricity grid.
Platform as a service (PaaS)
Platform as a Service (PaaS) is the delivery of a computing
platform and solution stack as a service.
PaaS offers a development platform for developers. The end users
write their own code and the PaaS provider uploads that code and
presents it on the web.
PaaS offerings facilitate deployment of applications without the
cost and complexity of buying and managing the underlying
hardware and software and provisioning hosting capabilities,
providing all of the facilities required to support the complete life
cycle of delivering web applications and services available from the
PaaS offerings may include facilities for application design,
application development, testing, deployment and hosting as well
as application services such as team collaboration, web service
integration. These services may be provisioned as an integrated
solution over the web.
Infrastructure as a Service (IaaS)
Delivery of the computing infrastructure as a fully outsourced
service. Managed hosting and development environments are the
services included in IaaS. The user can buy the infrastructure
according to the requirements at any particular point of time
instead of buying the infrastructure that might not be used for
months. IaaS is also sometimes referred to as Hardware as a
Software as a Secure Service (SaSS)
Software as a secure service (SaSS) is a derivative of software as a
Denotes a class of software as a service which emphasises security,
not only in the link to and from the service, and the storage of any
content by the software providing the service, but also in the
security of the user in terms of the ability to make consistent
backups and restores of any data stored in the service, in a nonproprietary format.
In other words, security in transmission, storage and control over
the user's own data.
It provides security in the link to the service, content storage on
the service, and non-proprietary format data backups and restores
of data stored on the service.
SaaS and SOA
Service-oriented architecture (SOA) is a flexible set of design
principles used during the phases of systems development and
integration in computing. A system based on a SOA will package
functionality as a suite of interoperable services that can be used
within multiple separate systems from several business domains.
Much like other software, SaaS can also take advantage of Service
Oriented Architecture to let software applications communicate
with each other. Each software service can act as a service
provider, exposing its functionality to other applications via public
brokers, and can also act as a service requester, incorporating data
and functionality from other services. Enterprise Resource
Planning (ERP) Software providers leverage SOA in building their
SaaS data escrow
SaaS Data Escrow is the process of keeping a copy of
critical software-as-a-service (SaaS) application data with an
independent third party.
Similar to source code escrow, where critical software source
code is stored with an independent third party, SaaS data escrow is
the same logic applied to data within a SaaS application. It allows
companies to protect and insure all the data that resides within
SaaS applications, protecting against data loss.
There are many and varied reasons for considering SaaS data
escrow including concerns about vendor bankruptcy, unplanned
service outages and potential data loss or corruption. Many
businesses are also keen to ensure that they’re complying with
their own data governance standards or want improved reporting
and business analytics against their SaaS data.
as a service
Application Service Provider
Platform as a service
Service oriented architecture