This paper describes a technique for formalizing metrics for COTS-based architectures. This technique is built upon the UML 2.0 metamodel and uses OCL as a metrics definition language. As a proof of concept, an example based upon a set of reusability metrics for fine-grained JavaBeans components is presented. 1.

Refactoring, in spite of widely acknowledged as one of the best practices of object-oriented design and programming, still lacks quantitative grounds and efficient tools for tasks such as detecting smells, choosing the most appropriate refactoring or validating the goodness of changes. This is a proposal for a method, supported by a tool, for cross-paradigm refactoring (e.g. from OOP to AOP), based on paradigm and formalism-independent modularity assessment.

Objective: To contribute with an overview on the current state of the art concerning metrics-based quality evaluation of software components and component-based assemblies. Method: Comparison of several approaches available in the literature, in terms of their scope, intent, definition technique and maturity. Results: Common shortcomings of current approaches, such as ambiguity in definition, lack of adequacy of the specifying formalisms and insufficient validation of current quality models and metrics for software components. Conclusions: Quality evaluation of components and component-based infrastructures presents new challenges to the Experimental Software Engineering community which are not conveniently dealt with by current approaches.

The milestones of the history of software development are paradigm shifts. Each paradigm brought its own features and new ways of composing them to assemble software systems. Understanding the impact of paradigm shifts encompasses making comparisons among systems built with different paradigms. Performing this kind of assessments is a very difficult exercise since the characterization of software assets is generally performed using paradigm-specific quantifications. In this paper we propose a metamodel for describing software products (either source code or design models) that is paradigm-independent. This metamodel, combined with a formal quantification approach, can help performing paradigm-independent software systems assessment. We illustrate the use of the proposed metamodel on a case study comparing functionally-equivalent systems produced with OOP and AOP. 1.

Abstract. Objective: In this paper we present a formalization of the definition of metrics to assess quality attributes of CORBA components and assemblies. The focus is on the formalization technique, rather than on the evaluation of the metrics themselves. Method: We represent a component assembly as an instantiation of the CORBA Component Model metamodel. The resulting meta-object diagram can then be traversed using Object Constraint Language clauses. With these clauses we construct a formal and executable definition of the metrics. Results: We demonstrate the expressiveness of our technique by formally defining metrics proposed informally by several authors on different aspects of components and assemblies ’ quality attributes. Conclusion: Providing a formal and executable definition of metrics for CORBA components and assemblies is an enabling precondition to allow for independent scrutiny of such metrics, which is, in turn, essential to increase practitioners ’ confidence on predictable quality attributes. 1

Abstract. This paper describes an independent validation study for a suite of reusability metrics for component based design published in the literature. The metrics under validation were originally proposed using a semi-formal notation, namely a combination of mathematical formulae with natural language descriptions for elementary parts of those formulae. They were then computed using proprietary tools. By contrast, we present a formalization for the metrics suite that combines the version 2.0 of the UML metamodel with OCL. This technique provides a formal, portable and executable definition of the metrics set that can be used to perform other cross-validations of the metrics suite. A prototype working environment to perform such cross-validation experiments, both with this and other metrics sets was developed and a metrics collection experiment using that environment is discussed. 1.

Objective: Formal definition of composition assessment metrics for CBSE, using an extension of the CORBA Component Model metamodel as the ontology for describing component assemblies. Method: Representation of a component assembly as an instantiation of the extended CORBA Component Model metamodel. The resulting meta-objects diagram can then be traversed using Object Constraint Language clauses. These clauses are a formal and executable definition of the metrics that can be used to assess quality attributes from the assembly and its constituent components. Results: Formal definition of context-dependent metrics that cover the different composition mechanisms provided by the CORBA Component Model and can be used to compare alternative component assemblies; a metamodel extension to capture the topology of component assemblies. Conclusion: Providing a formal and executable definition of metrics for CORBA component assemblies is an enabling precondition to allow for independent scrutiny of such metrics which is, in turn, essential to increase practitioners confidence on predictable quality attributes.

This paper describes an independent validation study for a suite of reusability metrics for component based design (CBD). We use an approach to metrics definition and collection that is different from the one originally proposed by the original authors. The metrics under validation were proposed using a semi-formal notation, namely a combination of mathematical formulae with natural language descriptions for elementary parts of those formulae. They were then computed using proprietary tools. In contrast, we will present a formalization for the metrics suite that combines the UML 2.0 metamodel with OCL. By using this technique, our contribution provides: (i) a formal, portable and executable definition of the metrics set that can be used by other researchers and practitioners to perform independent validations of the metrics suite; (ii) a prototype working environment to perform such independent validation experiments, both with this and other metrics sets.

overview of metrics-based approaches to support software

Abstract – Systematic reviews on software engineering literature have shown an insufficient experimental validation of claims, when compared to the standard practice in other wellestablished sciences. Poor validation of software engineering claims increases the risks of introducing changes in the software process of an organization, as the potential benefits assessment is based on hype, rather than on facts. The software engineering community lacks widely disseminated experimental best practices. This paper contributes with a model of the experimental software engineering process that captures the best practices in the area and is aligned with recent proposals for experimental data dissemination. This process model can be used either as a support in the definition of software engineering experiments or in conducting comparisons among experiment results.