@article {FHV14,
	title = {Connection Between Version Control Operations and Quality Change of the Source Code},
	journal = {Acta Cybernetica},
	volume = {21},
	number = {4},
	year = {2014},
	pages = {585{\textendash}607},
	abstract = {Software erosion is a well-known phenomena, meaning that software quality is continuously decreasing due to the ever-ongoing modifications in the source code. In this research work we investigated this phenomena by studying the impact of version control commit operations (add, update, delete) on the quality of the code. We calculated the ISO/IEC 9126 quality attributes for thousands of revisions of an industrial and three open-source software systems with the help of the Columbus Quality Model. We also collected the cardinality of each version control operation type for every investigated revision. We performed Chisquared tests on contingency tables with rows of quality change and columns of version control operation commit types. We compared the results with random data as well. We identified that the relationship between the version control operations and quality change is quite strong. Great maintainability improvements are mostly caused by commits containing Add operation. Commits containing file updates only tend to have a negative impact on the quality. Deletions have a weak connection with quality, and we could not formulate a general statement.},
	keywords = {Case Study, ISO/IEC 9126, Software Erosion, Software maintainability, Source Code Version Control},
	issn = {0324-721X},
	url = {http://publicatio.bibl.u-szeged.hu/8394/},
	author = {Farag{\'o}, Csaba and P Heged{\H u}s and V{\'e}gh, {\'A}d{\'a}m Zolt{\'a}n and Rudolf Ferenc}
}
@conference {FHF14,
	title = {The Impact of Version Control Operations on the Quality Change of the Source Code},
	booktitle = {Proceedings of the 14th International Conference on Computational Science and Its Applications (ICCSA 2014)},
	series = {Lecture Notes in Computer Science (LNCS)},
	volume = {8583},
	year = {2014},
	month = {jun},
	pages = {353{\textendash}369},
	publisher = {Springer-Verlag},
	organization = {Springer-Verlag},
	address = {Guimar{\~a}es, Portugal},
	abstract = {The number of software systems under development and maintenance is rapidly increasing. The quality of a system{\textquoteright}s source code tends to decrease during its lifetime which is a problem because maintaining low quality code consumes a big portion of the available efforts. In this research we investigated one aspect of code change, the version control commit operations (add, update, delete). We studied the impact of these operations on the maintainability of the code. We calculated the ISO/IEC 9126 quality attributes for thousands of revisions of an industrial and three open-source software systems. We also collected the cardinality of each version control operation type for every investigated revision. Based on these data, we identified that operation Add has a rather positive, while operation Update has a rather negative effect on the quality. On the other hand, for operation Delete we could not find a clear connection to quality change.},
	keywords = {Case Study, ISO/IEC 9126, Software Erosion, Software maintainability, Source Code Version Control},
	doi = {10.1007/978-3-319-09156-3_26},
	url = {https://link.springer.com/chapter/10.1007\%2F978-3-319-09156-3_26},
	author = {Farag{\'o}, Csaba and P Heged{\H u}s and Rudolf Ferenc}
}
@conference {BHS14,
	title = {{QualityGate SourceAudit}: a Tool for Assessing the Technical Quality of Software},
	booktitle = {Proceedings of the 2014 Software Evolution Week (Merger of the 18th IEEE European Conference on Software Maintenance and Reengineering \& 21st IEEE Working Conference on Reverse Engineering {\textendash} CSMR-WCRE 2014)},
	year = {2014},
	month = {feb},
	pages = {440{\textendash}445},
	publisher = {IEEE Computer Society},
	organization = {IEEE Computer Society},
	address = {Antwerp, Belgium},
	abstract = {Software systems are evolving continuously in order to fulfill the ever-changing business needs. This endless modification, however, decreases the internal quality of the system over time. This phenomena is called software erosion, which results in higher development, testing, and operational costs. The SourceAudit tool presented in this paper helps managing the technical risks of software deterioration by allowing imme-diate, automatic, and objective assessment of software quality. By monitoring the high-level technical quality of systems it is possible to immediately perform the necessary steps needed to reduce the effects of software erosion, thus reaching higher maintainability and lower costs in the mid and long-term. The tool measures source code maintainability according to the ISO/IEC 25010 based probabilistic software maintainability model called ColumbusQM. It gives a holistic view on software quality and warns on source code maintainability decline.},
	keywords = {ColumbusQM, development costs, internal system quality, ISO-IEC 25010 based probabilistic software maintainability, operational costs, QualityGate SourceAudit, software deterioration, Software Erosion, Source code maintainability, technical software quality, testing costs},
	doi = {10.1109/CSMR-WCRE.2014.6747214},
	url = {http://ieeexplore.ieee.org/document/6747214/},
	author = {Tibor Bakota and P Heged{\H u}s and Istv{\'a}n Siket and Lad{\'a}nyi, Gergely and Rudolf Ferenc}
}
