Quality Evaluation Models - High Level Models and Methodologies for Information Systems - page 94

relationships with the system: the number of opportunities, the number of threats,
and the rate at which both change (Whitworth and Zaic 2003 ).
Interaction between system and environment is determined by four key aspects:

“ (Whitworth and Zaic 2003 ).

Boundary refers to the need of clearly discriminating between what is the system
and what its environment is. The existence of this boundary is the prime aspect of a
system

boundary, internal structure, effectors and receptors ”

' s performance, in that it provides the first and most fundamental de nition

of purpose and goal.
Secondly, it is important to analyze the system is internal structure. This consists

of assessing the composition of the system, understanding how many parts compose
it, and determining what is the dynamics between those various parts.
Finally, effectors and receptors refer to the different types of feedback between
the system and its surroundings. The effectors are the elements that take action in
the environment, while the receptors

'

expertise concerns the collection of infor-
mation from the environment (Whitworth and Zaic 2003 ).
These four components are combined with the ultimate purpose of minimizing
risk and maximizing opportunity. They are the core of any system

'

s functionality,
and in the particular instance of IS, they are at the origin of the eight primordial
goals of the system, according to the WOSP methodology (Whitworth 2009 )
(Fig. 6.4 ).
In this methodology, WOSP de

'

nes eight goals that refer to an IS ' ideal traits:

“ flexibility, reliability, functionality, usability, connectivity,

privacy ” (Whitworth et al. 2006 ). The aims outlined by the WOSP model are
characteristics of IS that were already contemplated by researchers, but the inno-
vative factor in this model is the fact that it combines all of them in the same
framework. The features are not strange to this

extendibility, security,

field, but their symbiosis into a

common structure is original. It is WOSP ' is multidimensionality that distinguishes it

from other models.
This model can be visualized as a web with lines representing the interaction or
tension between the different points. Each goal is at a certain distance from the core
of the web, and the further it is from the center, the longer is its line, and conse-
quently, the higher is its performance. Hence, the area of the web consists in a

Fig. 6.4 Four aspects of
system - environment
interaction, according to
Whitworth and Zaic ( 2003 )