Unfortunately, the details have to be added
somehow anyway during the transformation of
design models into the real IT system. There are two
problems connected with that - the process of adding
the details is often unspecified, and second, the
modelling tools are not designed to support this. It is
usually unclear who adds the necessary details.
Formalisms in models are most of the time
inflexible - it is often not possible to model in a
given formalism with “less” detail and “more”
detail, or if it is possible, then essentially separate
models have to be created without explicit
connection between them. For example it is possible
to model a business process in a general way (just
specify a single chain of tasks to be performed in the
organization) or in a detailed way (specifying
conversations or message exchange protocols
between process participants as well as message
exchange formats and semantics), but there is little
connection between the general and detailed models
of the same process. Consequently it is usually
impossible to abstract from details in a systematic
way and see a simplified model.
Accuracy of the View is a challenge of selecting the
right point of view when modelling.
Multi aspect representations stems from the
inherent characteristic of different focal areas. First
it is hard to keep the multi aspects in sync. Models
evolve over time and maintaining multi aspect
models is even harder than maintaining a single
view one. Second, it seems, that when implementing
an IT solution it is hard to sustain all the aspects and
specific views on the modelled objects or situations
that has to be selected. This problem result in
information systems that usually adopt one view (or
approach, or method), which from the business point
of view makes them less flexible, constrained and
eventually may lead to the need to change the
system. If we accept this, then the question is how to
make educated decisions on which view would suit
best the goals set for an enterprise, the processes that
should be supported or the strategy to be
implemented. There is a deficiency in many models
and modelling approaches, because they don't give
straightforward answers to what will be the impact
on other parts of the model if we select certain
approach or view on some distant part of the model.
Change and Model Dependencies refer to the fact
that modelling usually is done in a constantly
changing environment.
Regarding the dynamic aspect of modelling - the
transition from AS-IS to TO-BE, the need for
transition may arise in two ways. Either the business
drives the need for change in the IT/IS layer, or that
the technology drives the change - which gives new
opportunities or creates certain restrictions for the
processes that are supported by IT solutions.
Assuming that we use modelling as approach to the
problem, and all the layers have their respective
models, the model of TO-BE differs from the model
of AS-IS. It is usually not a problem to identify the
differences in the models of a single layer. The
question is how the differences should propagate to
other layers. It is not entirely sure at this stage
whether such clues can be delivered automatically.
But the even modest support for noting these
changes and the consequences of changes (how did
change in the model X influenced the change in the
model Y) would be certainly beneficial to make
sense of the whole business / IT infrastructure
evolution process. Currently no tools or other
instrumental support exist to record this evolution
even in a single layer, therefore the challenge is even
greater for the multi-layered enterprise modelling.
4 CONCLUSIONS AND
OUTLOOK FOR THE FUTURE
The discussion of challenges and their consequences
to enterprise modelling leads to several conclusions
on how to deal with the challenges or what is still
necessary in enterprise modelling in order for it to be
able to ensure a better business and IT alignment.
It seems that ontologies applied at and between
different levels of enterprise modelling, despite their
inherent problems, would allow to build connections
between these levels and aid in creating coherent
multilevel models spanning across different focal
areas. The challenge in this will be to create a
working relations between the four types of
ontologies that has been presented in this article,
top-level ontology, domain ontology, task ontology,
and application ontology.
Secondly, current modelling approaches lack the
notion of model evolution or change, in the sense
that they do not adopt the change as the main driving
force in modelling. As indicated previously,
modelling transition from AS-IS to TO-BE might be
the key to show the mutual influences between the
business and IT layers of the enterprise. Currently,
there is little correspondence between the different
subsequent versions of the model of a given focal
area, except from the obvious one (e.g. “this object
is the same as in the previous version of the model”).
Since there is no explicit notion of change and
linkage between subsequent model versions, there is
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