{"id":{"repo_id":"brunel","oai_identifier":"oai:bura.brunel.ac.uk:2438/4527"},"canonical_url":"https://search.dev.ndltd.org/etd/brunel/oai:bura.brunel.ac.uk:2438/4527","repository":{"repo_id":"brunel","name":"University of Brunel","base_url":"https://bura.brunel.ac.uk/oai/request"},"display":{"title":"An empirical study of package coupling in Java open-source","abstract":"Excessive coupling between object-oriented classes in systems is generally acknowledged as harmful and is recognised as a maintenance problem that can result in a higher propensity for faults in systems and a „stored up‟ future problem. Characterisation and understanding coupling at different levels of abstraction is therefore important for both the project manager and developer both of whom have a vested interest in software quality. In this Thesis, coupling trends are empirically investigated over multiple versions of seven Java open-source systems (OSS). The first investigation explores the trends in longitudinal changes to open-source systems given by six coupling metrics. Coupling trends are then explored from the perspective of: the relationship between removed classes and their coupling with other classes in the same package; the relationships between coupling and 'warnings’ in packages and the time interval between versions in Java OSS; the relationship between some of these coupling metrics are also explored. Finally, the existence of an 80/20 rule for the coupling metrics is inspected. Results suggest that developer activity comprises a set of high and low periods (peak and trough‟ effect) evident as a system evolves. Findings also demonstrate that addition of coupling may have beneficial effects on a system, particularly if they are added as new functionality through the package Java feature. The fan-in and fan-out coupling metrics reveal particular features and exhibited a wide range of traits in the classes depending on their high or low values; finally, we revealed that one metric (fan-in) is the only metric that appears consistently to exhibit an 80/20 (Pareto) relationship.","abstract_html":"Excessive coupling between object-oriented classes in systems is generally acknowledged as harmful and is recognised as a maintenance problem that can result in a higher propensity for faults in systems and a „stored up‟ future problem. Characterisation and understanding coupling at different levels of abstraction is therefore important for both the project manager and developer both of whom have a vested interest in software quality. In this Thesis, coupling trends are empirically investigated over multiple versions of seven Java open-source systems (OSS). The first investigation explores the trends in longitudinal changes to open-source systems given by six coupling metrics. Coupling trends are then explored from the perspective of: the relationship between removed classes and their coupling with other classes in the same package; the relationships between coupling and 'warnings’ in packages and the time interval between versions in Java OSS; the relationship between some of these coupling metrics are also explored. Finally, the existence of an 80/20 rule for the coupling metrics is inspected. Results suggest that developer activity comprises a set of high and low periods (peak and trough‟ effect) evident as a system evolves. Findings also demonstrate that addition of coupling may have beneficial effects on a system, particularly if they are added as new functionality through the package Java feature. The fan-in and fan-out coupling metrics reveal particular features and exhibited a wide range of traits in the classes depending on their high or low values; finally, we revealed that one metric (fan-in) is the only metric that appears consistently to exhibit an 80/20 (Pareto) relationship.","abstract_has_math":false,"creators":["Mubarak, Asma"],"institution":"Brunel University, School of Information Systems, Computing and Mathematics","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Counsell, S","Hierons, RM"],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010","date_published":"2010","updated_at":"2026-07-24T01:23:24Z","subjects":["Software metrics","Evolution","Refactoring","Power law","Warning"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://bura.brunel.ac.uk/handle/2438/4527","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Counsell, S","Hierons, RM"]},{"key":"dc:creator","label":"Author","values":["Mubarak, Asma"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2010-08-27T10:14:39Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2010-08-27T10:14:39Z"]},{"key":"dc:date.issued","label":"Date","values":["2010"]},{"key":"dc:publisher","label":"Institution","values":["Brunel University, School of Information Systems, Computing and Mathematics"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Software metrics","Evolution","Refactoring","Power law","Warning"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://bura.brunel.ac.uk/handle/2438/4527"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University."]},{"key":"dc:description.abstract","label":"Abstract","values":["Excessive coupling between object-oriented classes in systems is generally acknowledged as harmful and is recognised as a maintenance problem that can result in a higher propensity for faults in systems and a „stored up‟ future problem. Characterisation and understanding coupling at different levels of abstraction is therefore important for both the project manager and developer both of whom have a vested interest in software quality. In this Thesis, coupling trends are empirically investigated over multiple versions of seven Java open-source systems (OSS). The first investigation explores the trends in longitudinal changes to open-source systems given by six coupling metrics. Coupling trends are then explored from the perspective of: the relationship between removed classes and their coupling with other classes in the same package; the relationships between coupling and 'warnings’ in packages and the time interval between versions in Java OSS; the relationship between some of these coupling metrics are also explored. Finally, the existence of an 80/20 rule for the coupling metrics is inspected. Results suggest that developer activity comprises a set of high and low periods (peak and trough‟ effect) evident as a system evolves. Findings also demonstrate that addition of coupling may have beneficial effects on a system, particularly if they are added as new functionality through the package Java feature. The fan-in and fan-out coupling metrics reveal particular features and exhibited a wide range of traits in the classes depending on their high or low values; finally, we revealed that one metric (fan-in) is the only metric that appears consistently to exhibit an 80/20 (Pareto) relationship."]},{"key":"dc:title","label":"Title","values":["An empirical study of package coupling in Java open-source"]}]}],"canonical_facts":{"dc:contributor.advisor":["Counsell, S","Hierons, RM"],"dc:creator":["Mubarak, Asma"],"dc:date.accessioned":["2010-08-27T10:14:39Z"],"dc:date.available":["2010-08-27T10:14:39Z"],"dc:date.issued":["2010"],"dc:description":["This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University."],"dc:description.abstract":["Excessive coupling between object-oriented classes in systems is generally acknowledged as harmful and is recognised as a maintenance problem that can result in a higher propensity for faults in systems and a „stored up‟ future problem. Characterisation and understanding coupling at different levels of abstraction is therefore important for both the project manager and developer both of whom have a vested interest in software quality. In this Thesis, coupling trends are empirically investigated over multiple versions of seven Java open-source systems (OSS). The first investigation explores the trends in longitudinal changes to open-source systems given by six coupling metrics. Coupling trends are then explored from the perspective of: the relationship between removed classes and their coupling with other classes in the same package; the relationships between coupling and 'warnings’ in packages and the time interval between versions in Java OSS; the relationship between some of these coupling metrics are also explored. Finally, the existence of an 80/20 rule for the coupling metrics is inspected. Results suggest that developer activity comprises a set of high and low periods (peak and trough‟ effect) evident as a system evolves. Findings also demonstrate that addition of coupling may have beneficial effects on a system, particularly if they are added as new functionality through the package Java feature. The fan-in and fan-out coupling metrics reveal particular features and exhibited a wide range of traits in the classes depending on their high or low values; finally, we revealed that one metric (fan-in) is the only metric that appears consistently to exhibit an 80/20 (Pareto) relationship."],"dc:identifier.uri":["http://bura.brunel.ac.uk/handle/2438/4527"],"dc:language.iso":["en"],"dc:publisher":["Brunel University, School of Information Systems, Computing and Mathematics"],"dc:subject":["Software metrics","Evolution","Refactoring","Power law","Warning"],"dc:title":["An empirical study of package coupling in Java open-source"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T01:23:24Z"}