A systematic literature review of open source software quality assessment models <s> Background <s> Software quality evaluation has always been an important part of software business. The quality evaluation process is usually based on hierarchical quality models that measure various aspects of software quality and deduce a characterization of the product quality being evaluated. The particular nature of open source software has rendered existing models inappropriate for detailed quality evaluations. In this paper, we present a hierarchical quality model that evaluates source code and community processes, based on automatic calculation of metric values and their correlation to a set of predefined quality profiles.1 <s> BIB001 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Open Source Software (OSS) has an increasing importance for the software industry. Similar to traditional (closed) software acquisition, OSS acquisition requires an assessment of whether its quality is sufficient for the intended purpose, and whether the chances of being maintained and supported in the future, as well as of keeping certain quality standards over time, are sufficiently high. In this paper, we present an approach toward a comprehensive measurement framework for OSS projects, developed in the EU project QualOSS. This approach takes into account product quality as well as process maturity and sustainability of the underlying OSS community. <s> BIB002 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Software quality models are a well-accepted means to support quality management of software systems. Over the last 30 years, a multitude of quality models have been proposed and applied with varying degrees of success. Despite successes and standardisation efforts, quality models are still being criticised, as their application in practice exhibits various problems. To some extent, this criticism is caused by an unclear definition of what quality models are and which purposes they serve. Beyond this, there is a lack of explicitly stated requirements for quality models with respect to their intended mode of application. To remedy this, this paper describes purposes and usage scenarios of quality models and, based on the literature and experiences from the authors, collects critique of existing models. From this, general requirements for quality models are derived. The requirements can be used to support the evaluation of existing quality models for a given context or to guide further quality model development. <s> BIB003 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Component-Based Software Development has become a popular approach to building software intensive systems. Besides using Commercial Off-The-Shelf components, an organization may choose to use Open Source Software components. Using OSS has been reported to have many benefits, but there are also challenges involved. Understanding the potential challenges of using OSS in developing products is important for practitioners, so they become aware of them and can anticipate them and take appropriate measures to address these challenges. We have performed a thorough review of the literature to identify challenges that may arise, as reported in the literature. This paper presents and discusses these findings. Researchers can discuss potential causes and solutions of our synthesized findings as well as benefit from provided references to literature on OSS challenges as input for future research. <s> BIB004 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Many open source web applications exist today and universities also find them useful. For instance, universities now manage most of their research output by storing them in their respective institutional repositories. These repositories are often built as open source web applications and known as repository software. Several of these exist but three popular ones include: DSpace, EPrints and Greenstone (DEG). These three are open source and built by different institutions. Considering their increasing adoption and usage by universities today, it would be useful to have a model that can compare between the quality of two or more web applications and suggest the better option to an institution intending to adopt one. This paper therefore proposes a model for measuring quality in open source web applications (focusing on repository software) by adapting existing quality models. The proposed model is used to measure quality in DEG. The proposed model is validated through real data and the results presented and discussed. Overall, the model rated DSpace as the better option. <s> BIB005 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Actually, software products are increasing in a fast way and are used in almost all activities of human life. Consequently measuring and evaluating the quality of a software product has become a critical task for many companies. Several models have been proposed to help diverse types of users with quality issues. The development of techniques for building software has influenced the creation of models to assess the quality. Since 2000 the construction of software started to depend on generated or manufactured components and gave rise to new challenges for assessing quality. These components introduce new concepts such as configurability, reusability, availability, better quality and lower cost. Consequently the models are classified in basic models which were developed until 2000, and those based on components called tailored quality models. The purpose of this article is to describe the main models with their strengths and point out some deficiencies. In this work, we conclude that in the present age, aspects of communications play an important factor in the quality of software <s> BIB006 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Evaluating software product quality (SPQ) is an important task to ensure the quality of software products. In this paper a systematic mapping study was performed to summarize the existing SPQ evaluation (SPQE) approaches in literature and to classify the selected studies according to seven classification criteria: SPQE approaches, research types, empirical types, data sets used in the empirical evaluation of these studies, artifacts, SQ models, and SQ characteristics. Publication channels and trends were also identified. 57 papers were selected. The results show that the main publication sources of the papers identified were journals. Data mining techniques are the most frequently approaches reported in literature. Solution proposals were the main research type identified. The majority of the selected papers were history-based evaluations using existing data, which were mainly obtained from open source software projects and domain specific projects. Source code was the main artifacts used by SPQE approaches. Well-known SQ models were mentioned by half of the selected papers and reliability is the SQ characteristic through which SPQE was mainly achieved. SPQE-related subjects seem to attract more interest from researchers since the past years. <s> BIB007 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Abstract Open Source Software (OSS) is a new paradigm to develop software by community, in which groups of developer collaborating each other. The method becomes very popular because the products of OSS projects, such as source code, documents, results of tests, are published by open-license. One of noticeable features of OSS is openness of project. Anyone can access the products of OSS projects. It is expected that the quality of products could be higher than those developed by conventional methods, as more people access OSS products and the chance to find defect could be larger. However, there are no established methods for the evaluation of OSS, neither actual terms of the evaluation of OSS. We propose an evaluation method, which is based on the maturity model of OSS development community. <s> BIB008 </s> A systematic literature review of open source software quality assessment models <s> Background <s> Predicting software product quality (SPQ)is becoming a permanent concern during software lifecycle phases. In this paper, a systematic mapping studywas performed to summarize the existing SPQ prediction(SPQP) approaches in literature and to organizethe selected studies according to seven classificationcriteria: SPQP approaches, research types, empiricaltypes, data sets used in the empirical evaluation of thesestudies, artifacts, SQ models, and SQ characteristics.Publication channels and trends were also identified.After identifying 182 documents in ACM Digital Library,IEEE Xplore, ScienceDirect, SpringerLink, and Googlescholar, 69 papers were selected. The results showthat the main publication source of the papers identifiedwas conference. Data mining techniques are themost frequently SPQP approaches reported in literature.Solution proposal was the main research type identified.The majority of the papers selected were history-basedevaluations using existing data which were mainly obtainedfrom open source software projects and domainspecific projects. Source code was the main artifactconcerned with SPQP approaches. Well-known SQmodels were hardly mentioned and reliability is the SQcharacteristic through which SPQP was mainly achieved.SPQP-related subject seems to need more investigationfrom researchers and practitioners. Moreover, SQ modelsand standards need to be considered more in futureSPQP research. <s> BIB009
Prior to the emergence of open source software (OSS) quality models, the McCall, Dromey and ISO 9126 models were already in existence BIB006 ). These models however did not consider some quality attributes unique to OSS such as community-a body of users and developers formed around OSS who contribute to the software and popularize it  ). This gap is what led to the evolution of OSS quality models. Majority of the OSS quality models that exist today are derived from the ISO 9126 quality model BIB006 BIB005 . It defines six internal and external quality characteristics, which are functionality, reliability, usability, efficiency, maintainability and portability. ISO 25010 replaced the ISO 9126 in 2010 (ISO/IEC 9126 2001) , it has the following product quality attributes (ISO/IEC 25010 2001) : functional suitability, reliability, performance efficiency, operability, security, compatibility, maintainability and transferability. The ISO 25010 quality in use attributes includes effectiveness, efficiency, satisfaction, safety and usability. It is important to note that ISO 25010 can serve as standard for OSS only in terms of product quality and Open Access *Correspondence: ssopam@gmail.com; sanjay.misra@covenantuniversity. edu.ng 1 Covenant University, Ota, Nigeria Full list of author information is available at the end of the article quality in use. It does not address unique characteristics of OSS such as the community. A key distinguishing feature of OSS is that it is built and maintained by a community  ). The quality of this community also determines the quality of the OSS BIB001 . From the literature, community related quality characteristics include BIB002 : maintenance capacity, sustainability, and process maturity. Maintenance capacity refers to the number of contributors to an OSS project and the amount of time they are willing and able to contribute to the development effort as observed from versioning logs, mailing lists, discussion forums and bug report systems. Furthermore, sustainability refers to the ability of the community to grow in terms of new contributors and to regenerate by attracting and engaging new members to take the place of those leaving the community. In addition, process maturity refers to the adoption and use of standard practices in the development process such as submission and review of changes, peer review of changes, provision of a test suite, and planned releases. Since the advent of the first OSS quality model in 2003 BIB005 ), a number of other models have since been derived leading to an increasing collection of OSS quality models. Quality models in general can be classified into three broad categories namely: definition, assessment and prediction models BIB007 BIB009 BIB003 ). Generally, OSS quality assessment models outline specific attributes that guide the selection of OSS. The assessment models are very significant because they can help software evaluators to select suitable OSS in the midst of alternatives BIB008 . However, despite the numerous quality assessment models proposed, there is still little or no adoption of these models in practice  BIB004 . In order to guide the formulation of newer models, there is need to understand the nature of the existing OSS quality assessment models. The aim of this study is to investigate the nature of the existing OSS quality assessment models by classifying them with respect to their quality characteristics, the methodology they use for assessment, and their domain of application so as to guide the formulation and development of newer models. Existing studies on OSS quality assessment models BIB006 BIB005 ) are largely descriptive reviews that did not seek to classify OSS quality assessment models along specific dimensions, or answer specific research questions. In contrast, this paper employs a methodical, structured, and rigorous analysis of existing literature in order to classify existing OSS quality assessment models and establish a template guide for model developers when they come up with new models. Thus, this study is a systematic literature review that investigates three research questions, namely: (1) what are the key quality characteristics possessed by the OSS assessment models? (2) What selection methods are employed for use in these assessment models? (3) What is the domain of application? In order to conduct this systematic review, the original guidelines proposed by  have been followed. The rest of this paper is structured as follows: "Methods" section describes the method of obtaining the existing OSS quality models. "Results" section presents the results obtained in the study, while "Summary and discussion" section discusses the findings of the study. "Conclusion and future work" section concludes the paper with a brief note.