integration and ensures the secure data movement
between the cloud consumer and multiple cloud
providers.
Arbitrage-Service: Service arbitrage means that a
broker can choose from different services from
various providers. A cloud broker, for example,
can choose a suitable selection (Cloud Service
Selection) out of various offerings based on
different criteria.
Whereas on the field of intermediation and
aggregation (e.g. on the topic of interoperability)
already a lot of scientific effort takes place
(Sundareswaran et al., 2012) and various solutions are
available (Sun et al., 2013; Gartner, 2013), there is
only limited knowledge and on a high level of
abstraction in the field of arbitration (Kalepu et al.,
2003; Mondal et al., 2010; Buyya et al., 2012). At this
level first scientific efforts were taken of Buyya et al.
(Buyya et al, 2012; Garg et al., 2011). Buyya looks
such a broker as a central role for a market-oriented
approach of cloud services (Garg et al., 2011).
Silas et al., (Silas et al., 2012) propose a service
middleware for efficient service selection. By using
the ELECTRE methodology of the selection process
is approached as a multi on criteria decision problem.
Many criteria, such as response time, service costs,
responsiveness, trust, scalability, performance,
flexibility thereby influence the selection process.
Deng et al. (2011) used for service selection also a
multi-criteria decision-making process, which is
based on the Fuzzy-AHP (Saaty, 1986) and TOPSIS
method.
Furthermore, (Deng-Neng et al., 2011) is using
trust as the sole criterion for the selection of service
providers. Garg et al., (2012) focus their work on the
indexing and classification of the provider, which is
required for a service switching. A so called cloud
service index with parameters such as service type,
price unit, security provider is used. The whole
concept is based on the provision of data by the
respective provider and thus does not provide
independence from the service provider.
The existing activities focus either on the side of
the classification of services or the decision support
methods for the customer. Grag et al., (2012) and
Hussain (2011) also complain about that today's
cloud based service evaluation and selection methods
and in particular functional requirements. For a
successful service selection and service mapping but
also the business needs, as well as non-functional
requirements such as potential regulators,
Performance, Support etc. must be considered and the
service characteristics are com-pared.
The field of Business / IT Alignment (BITA)
seems to be suitable. BITA aims to align, adapt and
integrate business strategy, IT strategy, business
infrastructure and IT infrastructure with each other
(Henderson et al., 1993; Papp, 2001). In this field
there exist various approaches (plugIT, 2012, Wolf et
al., 2011) on how BITA has to be applied and used.
However, these methods are not suitable for the
selection and placement of cloud services, because of
the time consuming processes. Such as experiences
from the plugIT project (2012) have shown in other
areas, the efforts of such frameworks are not practical
for the users.
With regards to the mapping mechanism, the
complexity of such structures have to imply that
corresponding comparison algorithms have to have a
high tolerance for structural deviations without
harming the semantic content of the compared
entities. One way to take this into account are
approximate comparison methods based on
similarity-based reasoning. Among them there exists
a wide range of techniques including Case Based
Reasoning techniques such as example-based
reasoning, instance-based reasoning, memory-based
reasoning, or analogical reasoning (Wolf et al., 2011;
Aamodt, 1994).
4 METHODOLOGY
At this stage of the research project, pragmatism is the
right stance, because it offers the greatest flexibility
within the research project. The disruptive nature of
cloud computing and the resulting complexity within
the vendor landscape might still hold sur-prises along
the way. As research progresses and knowledge for
the development of a mediation broker will mature, it
is crucial in this research to adapt quickly.
As discussed in the previous chapters extensively,
cloud computing evolves at a great pace and the focus
in this market changes constantly. As a consequence
it is getting more difficult to keep the pace and stay
on top of things in the shifting cloud environment.
This rapid evolvement in its early stage makes it even
harder to develop a robust theory to test and validate
(i.e. deductive reasoning), which could withstand the
disruptive nature of cloud computing. However,
literature is available in this area, which would favour
a deductive approach thoroughly. As a pragmatist and
while looking be-yond the horizon, it might be
meaningful to combine both approaches. In the first
stage the inductive approach helps to break down the
complexity and explore the transition in the cloud
vendor market. Then, in a second stage when the
complexity decreased and less debate is excited,