Cloud computing is no longer only a buzzword. Enterprises across the domain are talking about it; in other words, it has moved from “what it is” to “how can it help” the enterprise. Cloud computing is a paradigm shift for IT services and is not just a set of new technology and tools but is the change in the way we respond to the business problems today using technology. Cloud computing offers many benefits and that is the reason why enterprises are curious and excited about the cloud computing. Following are few key benefits that cloud computing offers: - Elastic Resource Capacity: Ability to re-provision the technology infrastructure resources on demand rapidly and inexpensively - Reduced Cost: Reduced Capital cost due to utility pricing based on usage. - Pay as you go model provides transactional pricing - Improved Reliability: Multiple redundant sites with automatic replication of data improves reliability - Better Scalability: On demand provisioning of resources to manage the peak load and quickly scale infrastructure - Global Reach: Readily available and accessible from anywhere. Regional data centers provided by cloud makes it available near to the target audience However, any technology transformation is not easy for organizations to adopt and there are pain points associated with it as the change does not happen overnight. It requires assessment, planning, validation, selling and convincing the stake holders for the change. The change adoption has to be incremental and stepwise. The change has to be evaluated with due diligence in specific needs of enterprise drivers and the application characteristic. This whitepaper will help you evaluate the right cloud service delivery model - IaaS, PaaS, SaaS

1. 1www.aditi.com
What Do
I Cloudify?
Cloud computing is no longer only a buzzword. Enterprises
across the domain are talking about it; in other words, it has
moved from “what it is” to “how can it help” the enterprise.
Cloud computing is a paradigm shift for IT services and is not
just a set of new technology and tools but is the change in
the way we respond to the business problems today using
technology.
This paper discusses cloud service delivery models and how
to choose your preferred delivery platform.
www.aditi.com
Sachin Sancheti
Cloud Architect, Aditi Technologies

2. 2www.aditi.com
Appraising Cloud and
its Service Delivery Models
Post the recent downturn, IT resource optimization is the key driver for most
of business transformation initiatives across all domains. Enterprises face some
specific challenges, namely, increased need for cost reductions, global model
for information exchange with partners, field agents and on-the-move
managers. These are challenges that result in the need for additional
infrastructure and IT.
Classification of the applications in an enterprise yields some standard support
function applications, a few short lived applications and periodic access
applications which could be the ideal candidates for IT optimization. Apart
from running only the “lights on” applications in this competitive environment,
enterprises need to be more agile and innovative to raise operational
efficiency, reduced management efforts, fast time to market and realize
innovative ideas to improve competitive edge.
Cloud computing is an innovative service delivery model with benefits of pay
as you go, instant and elastic infrastructure which is readily available and
reliable. According to the recent surveys and research it is established that
cloud computing can help enterprises to reap benefits and build value for
smooth operations, cost saving and innovative execution etc.

3. 3www.aditi.com
Cloud computing is no longer only a buzzword. Enterprises across the domain
are talking about it; in other words, it has moved from “what it is” to “how can
it help” the enterprise. Cloud computing is a paradigm shift for IT services and
is not just a set of new technology and tools but is the change in the way we
respond to the business problems today using technology.
Cloud computing offers many benefits and that is the reason why enterprises
are curious and excited about the cloud computing. Following are few key
benefits that cloud computing offers:
 Elastic Resource Capacity: Ability to re-provision the technologic
infrastructure resources on demand rapidly and inexpensively
 Reduced Cost: Reduced Capital cost due to utility pricing based on usage.
Pay as you go model provides transactional pricing
 Improved Reliability: Multiple redundant sites with automatic replication
of data improves reliability
 Better Scalability: On demand provisioning of resources to manage the
peak load and quickly scale infrastructure
 Global Reach: Readily available and accessible from anywhere. Regional
data centers provided by cloud makes it available near to the target
audience
However, any technology transformation is not easy for organizations to
adopt and there are pain points associated with it as the change does not
happen overnight. It requires assessment, planning, validation, selling and
convincing the stake holders for the change. The change adoption has to be
incremental and stepwise. The change has to be evaluated with due diligence
in specific needs of enterprise drivers and the application characteristic.
What are the layers of
Architecture?Case of Cloud

4. 4www.aditi.com
ABOUT ADITI
Cloud computing brings all together a new set of possibilities to be leveraged
from the service delivery point of view. At high level below are the major
delivery models available for cloud computing adoption for any enterprise.
Image Reference: Microsoft Windows Azure Training Kit
The image clearly depicts what does cloud service provider manages and what
needs to be managed by the subscribers. This also explains the kind of control
subscribers have on their applications, data and infrastructure in each of the
cloud service delivery model. A prominent observation can be drown from
above image is “As you move from IaaS towards SaaS the control reduces and
simplicity increases”.
What are the layers of
Architecture?
Cloud Service Delivery
Models: IaaS, PaaS & SaaS

5. 5www.aditi.com
Let us briefly expand each of the cloud service delivery models.
SaaS - Software as a service: This deployment model provides a finished
application or solution as a service. It is a generalized application with
support for limited customization offered through cloud. Since it is
generalized solution, it has limitations for enterprises to map their isolated
customized implementation and heterogeneous data stores to avail this
solution. SaaS might turn out a good offering for smaller organizations to
address their limited business process needs. For bigger enterprises, a rich
set of functionalities (SaaS) with easy configuration to be able fit into their
context, would appeal.
PaaS - Platform as a service: This deployment model provides building
blocks to develop and assemble a customized solution in the cloud. As it has
to be built by the end users it provides a lot of flexibility in terms of
implementation but asks for initial investment for building the solution over
the cloud. This model is very flexible and capable of addressing all the needs
of custom processes, custom databases and other peculiar requirements of
the enterprises. PaaS provides high class services like operating system,
database storage, reporting framework, caching, integration frameworks etc.
which makes the application development a fast paced reliable matter.
Large enterprises would find this model very useful to overcome the
challenges like procurements, lying investment, un-optimized usage etc.
faced by their existing on premise applications.
IaaS – Infrastructure as a service: In this model vendors provide hardware
infrastructure as a service and customers need to deploy their software
starting from the operating system to the end application. This model
addresses only the need of delivering a dynamic hardware infrastructure.
Using this model enterprise will have to address the need of software
licensing and deployment by themselves which limits the benefits of cloud
computing platform. Since, it provides infrastructure on demand it makes
appealing to deploy line of business applications deployed on IaaS without
getting locked to any specific vendors as the case in SaaS and PaaS.
Enterprises who are ready to invest in managing their infrastructure, software
licensing etc. might find IaaS appealing because only the physical location of
the hardware changes rest everything else mostly remains same with the
benefit of dynamic infrastructure.

6. 6www.aditi.com
ABOUT ADITI
Enterprises can choose to select their cloud platform of choice based on the
following criteria’s described in the table below, driven by factors which makes
business sense in their respective domains.
Figure: Cloud Delivery Model – Feature Characteristics
What are the layers of
Architecture?
How to Choose your
Preferred Cloud Platform

7. 7www.aditi.com
Above model suggests the characteristics of each deployment model and the
feature sets offered by each one of them. Interesting continuum to be looked
at is as you go from IaaS towards SaaS the control decreases and the simplicity
increases and these could play the main drivers in decision making for finding
out X in “X as a Service” choice of cloud service delivery.
We can go on adding the criteria with specific weightage system and evaluate
these service delivery channels for the right fitment of application and
enterprise drivers.
We would like to provide few scenarios with choice of cloud service delivery
model driven by specific characteristics or feature required in for the
application.
Generic and common support functionality without being need to have
complete control on the application with maximum simplicity and reduced
management cost, e.g. Email Service – SaaS
Specific business functionalities and processes with reduced management
efforts and high time to market. To achieve this, the PaaS building blocks
would make it a better choice. E.g. procurement process, Line of Business
applications
Specific business functions with high need of control over application and data
even at the price of higher management efforts and slightly more time to
market
Enterprises are moving into the next stage of cloud adoption, rather than just a
feel good factor cloud has moved to a serious business proposition slab. Here
we tried to put a standard case for cloud with differentiating the three cloud
service delivery models with their characteristics and scenarios to keep the
decision of cloud adoption moving forward.
ABOUT ADITI

8. www.aditi.com
USA WEST
JONATHAN PARKER
jonathanp@aditi.com
USA CENTRAL
JOHN SCHINDLER
johns@aditi.com
USA EAST
UMESH WASON
umeshw@aditi.com
EMEA
KAUSHIK BANERJEE
kaushikb@aditi.com
APAC
PAWAN BORAR
pawanb@aditi.com
Microsoft Cloud Partner of the Year
We take our own medicine. We run our own apps on Azure.
We help Microsoft's internal IT implement Azure.
65+ companies trust us with Azure.
ABOUT US
Aditi helps ISVs, web businesses and enterprises lev-
erage the power of cloud, social and mobile to drive
competitive advantage. Our global leadership in Az-ure
transformation is established around 3 core strengths:
Deep global partnership with Microsoft
IP led transformation acceleration services
100+ delta force team on Azure
To learn more, visit www.aditi.com