SEKE 2012 Proceedings - Knowledge Systems Institute

equirement specification with the case base and gauges the
level of quality thereof. Praehofer and Kerschbaummayr [6]
defined a tool called CASA (Computer Aided Systems
Architecting) focused on reusing artifacts of Requirements
Engineering. The similarity calculation method takes into
account the structural organization of the documents.
Similarities are thereby found between an input artifact and the
Artifacts Base, to find the artifacts that are structurally similar
to the input artifact. Based on this, the tool tries to reuse similar
structures to create new artifacts. In most of the approaches that
use CBR in the activities and phases of Software Engineering,
we identified the single and prevalent use of the attribute-value
formalism for representation and retrieval of similar cases
previously stored in the case base.
III. AN ARTIFICIAL INTELLIGENCE APPROACH FOR REUSE
OF EXPERIENCES IN REQUIREMENTS ENGINEERING
Intelligent Systems that use techniques of Case Based
Reasoning (CBR) are based on the simple idea that, in similar
problems, similar solutions apply. CBR is an approach to
problem solving and experience-based learning, solving
problems by retrieving and adapting past experiences – called
cases – stored in a Case Base [7]. Specifically in the Software
Engineering community, there is a consensus that most
problems are recurring, therefore managing cases from
previous projects enables the implementation of successful
solutions in several new projects, avoiding waste of resources
to address repeating situations.
The knowledge base of a CBR system is represented in the
form of cases, a Case Base, that describe concrete experiences
of problems that have occurred and the solution(s) that were
applied. In this paper, we propose a hybrid formalism for
representation of a case: object-oriented and natural language.
Figure 1 shows a class diagram in UML for the representation
of a case. A case is described by a Problem and one or more
objects of the Solution class.
The basic attributes of a problem are: (i) project — name of
project where the case was verified; (ii) phase — phase of
software engineering where the problem occurred, for example:
“Requirements”; (iii) sub-phase — sub-phase where the
problem occurred, for example: “Requirements Elicitation,”
“Requirements Analysis,” etc.; (iv) artifact — artifact where
the problem was found, for example: “Use Case,” “Business
Rules,” etc.; (v) causer — who or what caused the problem, for
example, “Person,” “Technology,” “Process,” etc.; (vi) cause
— cause(s) of the problem. Some examples include: “usage
case scenario unspecified,” “business rule unspecified,”
“change in business rule unspecified,” “traceability matrix
incomplete,” etc.
These basic attributes serve as an initial qualification of the
problem. However, they are not enough to express it fully and
with all the specificities necessary for possible reusability.
Additionally, in order to enable a complete and natural
representation of a problem, we propose the attribute called
description that contains a textual report on the problem related
to the case.
Additionally, the basic attributes of a solution are: (i) action
— description of what was done to solve the problem; (ii)
executor — who performed the action; (iii) artifact — artifacts
to be changed to the solution to be implemented; and (iv)
involved — people, processes or organizations who have been
affected by the deployment of the solution.
FIGURE 1. CLASS DIAGRAM OF THE CASE BASE, IN UML.
The process proposed to support the reuse of experiences in
RE using techniques of CBR and NLP is shown in Figure 2 and
detailed below.
6
3
4
5
FIGURE 2. ARCHITECTURE OF THE PROCESS TO SUPPORT THE REUSE OF
EXPERIENCES IN ER.
2
1
575