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expressions might pose usability problems to the
stakeholders as well as those developers who are not
fluent with the formal logic.
Even though the courteous logic representations
are more English-like with less usage of arrows and
symbols, still accepting a new approach is not very
encouraging until its benefits are realized. Secondly,
some amount of training would have to be imparted
to the involved parties in requirements phase in
order to make them understand the syntax and the
querying mechanism. Third, translating the
requirements corpus to the courteous logic
expression would be time-consuming and would
depend on the individual’s expertise and skills.
Automated conversion from natural language to
these representations would certainly be an
advantage but doing that itself poses natural
language parsing challenge.
We still hope that benefits drawn from using
non-monotonic formal representations of
requirements will outweigh the threats.
Requirements of varying domains are of varied
nature and not one kind of model is able to
sufficiently express all the aspects of the system. A
domain which is rule-intensive and has multiple
conflicting views and requirements would certainly
be benefitted by courteous logic based
specifications.
6 CONCLUSIONS
In this paper, we have successfully addressed the
problem of identifying and analyzing the logical
inconsistency in the software requirements using
courteous logic based requirements specifications in
our work. We have shown that these specifications,
being an executable model of the system’s
requirements, not just identify implicit
inconsistencies but also help in identifying and
specifying presuppositions explicitly. The results
from the case-studies are encouraging. Tractable
inferencing and scalability of the representations are
some of the motivating factors towards using
courteous logic based specifications. We have also
demonstrated that fixing the inconsistency by rule-
prioritization does not entail a major change in the
existing requirements specification. This aspect
makes these expressions a suitable choice from
software maintenance point of view. Though the
requirements analysts might not find the idea of
using courteous logic comfortable, but since these
representations are relatively simpler; easy to
comprehend and natural language like, we hope that
with small amount of training these could be well-
taken by the practitioners as well.
We further aim to refine the current proposed
requirements representations and incorporate the
second interpretation of inconsistency – traceability;
and then develop a semantic framework for
automated analysis of requirements. We see our
framework as a foundation towards integrated
framework for semantic software engineering.
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