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Chapter 7. Implications
ity, that is, because there are a larger number of abstractions that developers
have to deal with over time. However, when we consider the
distribution of size and complexity metrics, we notice that the distribution
of all measures fall within a tight boundary (see Chapter 5). In any
given software system, though there is variation, the overall consistency
in the shape suggests that developers either explicitly or implicitly take
correction action in order to maintain the overall distribution of the
size as well as complexity. The only material increase in complexity at
the system level is not a consequence of complexity of a certain set of
classes, but rather due to the size of the system as a whole and increase
in the absolute number of complex classes.
Our observations related to complexity introduce uncertainty in interpreting
the law of Increasing Complexity. The law as stated suggests
that complexity increases unless effort is put into reducing it, that is,
it implies that complexity can be managed or reduced. In our study, we
find that (i) there is an absolute increase in the total number of classes,
and (ii) developers either intentionally or otherwise manage to contain
the distribution of complexity between the various classes. These findings
lead us to argue that although the distribution of complexity can
be managed, the volumetric complexity that arises because of the size
of the system cannot be reduced without a corresponding reduction in
functionality (assuming a competent development team).
Feedback and Regulation
The third law, Self Regulation states that evolution is regulated by feedback
[166]. We do not collected direct quantitative data related to feedback.
However, the bounded nature of Gini Coefficients across multiple
software systems provides indirect support for this law. Feedback can
be caused by different drivers. For instance, developers will get feedback
from a set of classes that are too large or complex, especially if
these classes are defect prone. Feedback can also be driven by team
dynamics as well as the cultural bias (strong team habits) that influence
how software is constructed. Hence, it is likely that there are
potentially multiple sources of feedback at work in order to regulate the
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