A measurement-based approach for assessing the influence of import-coupling on the maintainability of ocl expressions

Resumen

ALTHOUGH THE COMBINATION OF UML AND OCL LANGUAGUES PROVIDES THE EXPRESSIVENESS NEEDED TO CAPTURE ALL MODEL CONSTRAINTS, THEIR COMBINED USE DO NOT NECESSARILY GUARANTEE THAT A 'GOOD' MODEL WILL BE PRODUCED, IN ORDER TO ASSESS THE QUALITY OF OCL EXPRESSIONS WITHIN UML MODELS, THE AVAILABILITY AT EARLY STAGES OF RELIABLE INDICATORS ARE ESSENTIAL. A HUGE AMOUNT OF MEASURES HAVE BEEN DEFINED FOR MEASURING QUALITY CHARACTERISTICS OF UML MODELS, BUT ALL OF THEM HAVE ONLY BEEN FOCUSED ON THE MODEL ELEMENTS EXPRESSED BY DIAGRAMMATIC NOTATION, WITHOUT CONSIDERING OCL FACILITIES. THIS THESIS IS FOCUSED ON ASSESSING THE INFLUENCE OF IMPORT-COUPLING ON OCL EXPRESSIONS MAINTAINABILITY (MODIFIABILITY AND COMPREHENSIBILITY) THROUGH A METHODOLOGICAL DEFINITION OF A SET OF MEASURES FOR OCL EXPRESSIONS. THIS INFLUENCE IS INDEED PRODUCED DUE TO THE FACT THAT STRUCTURAL PROPERTIES OF OCL EXPRESSIONS AFFECT THE COGNITIVE COMPLEXITY OF MODELERS, AND HIGH COGNITIVE COMPLEXITY LEADS TO THE OCL EXPRESSION TO EXHIBIT UNDESIRABLE EXTERNAL QUALITIES SUCHA AS A LOW MAINTAINABILITY. FOR THAT REASON, ITS IS IMPORTANT TO EXPLAIN THE MEASURES CONSIDERING NOT ONLY THE STRUCTURAL PROPERTIES OF OCL EXPRESSIONS BUT THE COGNITIVE COMPLEXITY OF MODELERS THROUGH A PSYCHOLOGICAL EXPLANATION FOR OBTAINING A PRECISE DEFINITION. IN THIS PH.D. THESIS NEW KINDS OF COUPLING MEASURES ARE DEFINED IN TERMS OF CORE CONCEPTS OF OCL: NAVIGATIONS, COLLECTIONS OPERATIONS AND CONTEXTUAL OBJECTS. MOREOVER, WE DEFINE THE MEASURES THROUGH A THOUGHTFUL FORMAL DEFINITION AND A THEORETICAL AND EMPIRICAL VALIDATION. FOR THEIR THEORETICAL VALIDATION THE ADAPTATION OF EXISTING FRAMEWORKS OF COUPLING MEASURES WAS NEEDED AND IS CAREFULLY PRESENTED. REGARDING THEIR EMPIRICAL VALIDATION, WE ASCERTAIN THROUGH THREE FAMILIES OF EXPERIMENTS IF ANY RELATION EXISTS BETWEEN OCL MEASURES, AND TWO MAINTAINABILITY SUB-CHARACTERISTICS. THE EMPIRICAL RESULTS REVEAL THAT THERE IS EMPIRICAL EVIDENCE THAT IMPORT-COUPLING IS STRONGLY CORRELATED WIT