D.3.3 ALGORITHMS FOR INCREMENTAL ... - SecureChange

Chatzoglou et al. [4] conducted a study about the management of requirements capture
and analysis (RCA) process, to investigate the presence of significant differences between
projects developed by different people and organisations. The study identifies as
main challenging aspect the lack of adoption of a methodology during the RCA process.
Several studies discuss the challenges associated with requirements modeling. Lubars
et al. [11] summarized the findings of a field study involving ten organizations, focusing
on the problems of vaguely stated requirements and requirements prioritization.
Other issues were the unclear relation of performance requirements with parts
of dataflow/control flow specifications. In [2], Bertolino et al. provided an approach
for validating a domain model with experts ensuring the model captures properly the
intended domain knowledge. Another relevant work include the one of Maiden et al.
[12] who have conducted workshops with stakeholders using a concurrent engineering
process focusing on system goal modeling to model the future system.
The closest works to ours include the studies by Herrmann et al. [6], Welsh and
Sawyer [16], Kamsties et al. [9], Karlsson et al. [10], and Carlshamre et al. [3]. Herrmann
et al. described a process for capturing delta requirements (requirements describing
enhancements) deducing the level of detail to be maintained in the existing
system. In another study, Welsh and Sawyer use requirement traceability information
to handle requirement changes in Dynamic Adaptive System’s (DAS). They also propose
an extension to i* strategic rationale models to aid changing a DAS. Kamsties et
al. and Carlshamre et al. have investigated the role of requirements interdependencies
when new requirements need to be implemented for next system releases. Kamsties et
al. summarized the results of a workshop on requirements engineering held with practitioners
from ten small and medium enterprises. The main result from the workshop
was that new requirements implementation can cause unpredictable interactions with
requirements that are already implemented. Carlshamre et al. conducted a survey of
five different companies that has shown that visualization of requirement interdependencies
is efficient in identification of salient characteristics of requirements. Karlsson
et al. pointed the importance to have methods to cope with changing requirements.
Compared to above studies on changing requirements, the user study we have conducted
does not only aim at understanding how requirements evolution is handled in
an industrial setting (the ATM domain) but it also focused on validating our concrete
approach to deal with requirements evolution.
3 An Approach to Requirements Evolution
This section gives an overview of our approach [15] to manage the evolution of requirements.
Requirements evolution refers to changes in the requirements of a system. In
our work we consider two categories of evolution: controllable and observable. Controllable
evolutions are under the control of system designers who intentionally change
the system design in order to fulfill high level requirements proposed by stakeholders.
In other words, they are designers’ moves to identify design alternatives to implement
a system. Observable evolutions, instead, represent evolutions which are not under the
control of the designer, but that can be somehow detected when they happened or whose
future likelihood can be estimated with a certain confidence by the stakeholders. To
support decision making process, our proposed approach [15] incorporates these kinds
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