Information Technology Reference
In-Depth Information
the calculations are based on the analysis
of the Yankee Group(Yankee, 2006).
performance. Computers in a cloud computing
system boot and run faster because they have
fewer programs and processes loaded into mem-
ory (Miller, 2009). Compatibility is another at-
tribute that is supported by cloud computing.
Documents created in a Web application can be
read and processed without any special installation
on the users PCs. Increased data reliability is also
ensured as cloud is considered the ultimate back-
up. Interoperability and availability are two
other quality characteristics of cloud computing.
Interoperability and availability allow user to have
access to the system any time, anywhere by any
computer or network.
On premise software advantages involve data
accessibility, ownership and safety. The biggest
advantage of on-premise software is that busi-
nesses have complete control over their critical
business data (MacGowan, 2006). This is also a
•
Hardware costs for the second to the fifth
year are calculated as 5% of the costs of
the first year.
•
Training costs varies based on the number
of users.
B. Define Quality Characteristics
Quality characteristics are closely associated to
business goals and most of the times are defined
as non-functional requirements. An initial assess-
ment involves the definition of non functional
requirements and their priority. Table 12 sum-
marizes quality attributes and which of the two
solutions best incorporates them.
Among the quality characteristics that are
incorporated in cloud computing is improved
Table 12. Quality characteristics
Quality Attribute
Cloud vs On premise?
Reliability
Reliability is an indicator of the ability of system to perform its required functions. Cloud-based
providers are usually better equipped to recover from a failure. Most providers guarantee their uptime
and have built-in continuity systems to ensure continuity of the operations.
Availability
Cloud solutions offer instant and universal access to the data and the applications of the customer
thorough an internet connection. On the other hand cloud computing is impossible if you can't con-
nect to the Internet or you have low connection speed.
Flexibility & Customization
Customization and integration are considered to be better addressed in on premise solutions. With
the software running on its premises, a business retains complete control over its entire hardware and
software environment, including the flexibility to select the peripherals and third-party applications
that best complement and support its processes (McGowan, 2006).
Data confidentiality
The biggest advantage of on-premise software is that businesses have complete control over their
critical business data. This data is physically located on a business's premises and does not require
the transmission and storage of data off-site. Owning the hardware and supporting systems provides
a business with maximum control.
Back ups
Cloud-based solutions are generally considered to ensure a more secure backup of data and data
recovery as data stored in the cloud are replicated across multiple machines. Still there are arguments
in case of data loss in cloud you have no physical or local backup.
Interoperability
The ultimate cloud computing advantage is device independence (McGowan,). Existing applications
and documents are visible even if local systems and devices alter.
Maintenance and upgrades
Maintenance and upgrade is an intensive and time consuming task especially for web applications
where servers, storage, software, backup systems and network are in constant operation. In case of
hosted applications this burden is transferred to the provider and usually agreed upon SLAs.
Usability
McGowan states that many web-based applications do not provide the same functionality and features
compared to their desktop-based brethren. Users that are tight with existing desktop applications might
find interesting the learning curve of the web based corresponding applications.
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