Editing Software architecture (section)

== Software architecture topics ==

=== Software architecture and agile development ===
{{main|Agile development}}

There are also concerns that software architecture leads to too much [[big design up front]], especially among proponents of [[agile software development]]. A number of methods have been developed to balance the trade-offs of up-front design and agility,<ref name="Boehm2004">{{cite book |title=Balancing Agility and Discipline |last1=Boehm|first1=Barry|last2=Turner|first2=Richard|year=2004|publisher=Addison-Wesley|isbn=978-0-321-18612-6}}</ref> including the agile method [[dynamic systems development method|DSDM]] which mandates a "Foundations" phase during which "just enough" architectural foundations are laid. ''[[IEEE Software]]'' devoted a special issue to the interaction between agility and architecture.

=== Software architecture erosion ===
Software architecture erosion refers to a gradual gap between the intended and implemented architecture of a software system over time.<ref name="Ruiyin2022">{{Cite journal | last1 = Li | first1 = Ruiyin | last2 = Liang | first2 = Peng | last3 = Soliman | first3 = Mohamed | last4 = Avgeriou | first4 = Paris | doi = 10.1002/smr.2423 | title = Understanding software architecture erosion: A systematic mapping study | journal = [[Journal of Software: Evolution and Process]]| volume = 34 | issue = 3 | pages = e2423 | year = 2022 | url = https://onlinelibrary.wiley.com/doi/abs/10.1002/smr.2423| arxiv = 2112.10934 }}</ref> The phenomenon of software architecture erosion was initially brought to light in 1992 by Perry and Wolf alongside their definition of software architecture.<ref name="PERRY1992"/>

Software architecture erosion may occur in each stage of the software development life cycle and has varying impacts on the development speed and the cost of maintenance. Software architecture erosion occurs due to various reasons, such as ''architectural violations'', ''the accumulation of technical debt'', and ''knowledge vaporization''.<ref name="Ruiyin2021">{{Cite book | last1 = Li | first1 = Ruiyin | last2 = Liang | first2 = Peng | last3 = Soliman | first3 = Mohamed | last4 = Avgeriou | first4 = Paris | doi = 10.1109/icpc52881.2021.00037 | title = The 29th IEEE/ACM International Conference on Program Comprehension (ICPC) | chapter = Understanding architecture erosion: The practitioners' perceptive | pages = 311–322 | year = 2021 | isbn = 978-1-6654-1403-6 | url = https://ieeexplore.ieee.org/document/9463012}}</ref> A famous case of architecture erosion is the failure of Mozilla Web browser.<ref>van Gurp, J. and Bosch, J.: 2002, Design erosion: Problems and causes, Journal of Systems and Software 61(2), 105–119.</ref> Mozilla is an application created by Netscape with a complex codebase that became harder to maintain due to continuous changes.  Due to initial poor design and growing  architecture erosion, Netscape spent two years redeveloping the Mozilla Web browser, demonstrating the importance of proactive architecture management to prevent costly repairs and project delays.

Architecture erosion can decrease software performance, substantially increase evolutionary costs, and degrade software quality. Various approaches and tools have been proposed to detect architecture erosion. These approaches are primarily classified into four categories: consistency-based, evolution-based, defect-based, and decision-based approaches.<ref name=" Ruiyin2022"/> For instance, automated architecture conformance checks, static code analysis tools, and refactoring techniques help identify and mitigate erosion early.

Besides, the measures used to address architecture erosion contain two main types: preventative and remedial measures.<ref name=" Ruiyin2022"/> Preventative measures include enforcing architectural rules, regular code reviews, and automated testing, while remedial measures involve refactoring, redesign, and documentation updates.

=== Software architecture recovery ===
{{main|Software architecture recovery}}

Software architecture recovery (or reconstruction, or [[reverse engineering]]) includes the methods, techniques, and processes to uncover a software system's architecture from available information, including its implementation and documentation. Architecture recovery is often necessary to make informed decisions in the face of obsolete or out-of-date documentation and 
[[#Software architecture erosion|architecture erosion]]: implementation and maintenance decisions diverging from the envisioned architecture.<ref>
Lungu, M. "Software architecture recovery", University of Lugano, 2008. 
http://www.slideshare.net/mircea.lungu/software-architecture-recovery-in-five-questions-presentation
</ref> Practices exist to recover software architecture as [[static program analysis]]. This is a part of the subjects covered by the [[software intelligence]] practice.