Fabrizio Fioravanti

Estimation and prediction metrics for adaptive maintenance effort of object-oriented systems

Many software systems built in recent years have been developed using object-oriented technology and, in some cases, they already need adaptive maintenance in order to satisfy market and customer needs. In most cases, the estimation and prediction of maintenance effort is performed with difficulty due to the lack of metrics and suitable models. In this paper, a model and metrics for estimation/prediction of adaptive maintenance effort are presented and compared with some other solutions taken from the literature. The model proposed can be used as a general approach for adopting well-known metrics (typically used for the estimation of development effort) for the estimation/prediction of adaptive maintenance effort. The model and metrics proposed have been validated against real data by using multilinear regression analysis. The validation has shown that several well-known metrics can be profitably employed for the estimation/prediction of maintenance effort.

A study on fault-proneness detection of object-oriented systems

Fault-proneness detection in object-oriented systems is an interesting area for software companies and researchers. Several hundred metrics have been defined with the aim of measuring the different aspects of object-oriented systems. Only a few of them have been validated for fault detection, and several interesting works with this view have been considered. This paper reports a research study starting from the analysis of more than 200 different object-oriented metrics extracted from the literature with the aim of identifying suitable models for the detection of the fault-proneness of classes. Such a large number of metrics allows the extraction of a subset of them in order to obtain models that can be adopted for fault-proneness detection. To this end, the whole set of metrics has been classified on the basis of the measured aspect in order to reduce them to a manageable number; then, statistical techniques were employed to produce a hybrid model comprised of 12 metrics. The work has focused on identifying models that can detect as many faulty classes as possible and, at the same time, that are based on a manageably small set of metrics. A compromise between these aspects and the classification correctness of faulty and non-faulty classes was the main challenge of the research. As a result, two models for fault-proneness class detection have been obtained and validated.

Managing music in orchestras

The typical orchestra manages a huge amount of information. A symphonic works main score often runs to more than 100 pages, while an operatic score can run 600 or more. From the main score, the conductor draws some 15 to 30 different instrumental parts and distributes them to 40 or more lecterns so that 70 musicians can play from them during rehearsals and performances. This overhead increases significantly if the piece requires a chorus as well. A typical performance ranges from a few minutes to more than two hours. Individual musicians often make simple changes to the score, writing them manually on their parts during rehearsals, most often by adding interpretation symbols such as dynamics, expression marks, and string bowings. More complex changes-such as arrangements for different instruments, transpositions, and the deletion or addition of music sections-must be decided by the conductor. Operas, ballets, and new symphonic works frequently require such time-consuming modifications. Many performing organizations and publishers could benefit from a computerized option that allows storage of multiple versions and reduces the amount of repetitive work involved. The authors discuss their approach: the Music Object-Oriented Distributed System.

Assessment of system evolution through characterization

Owing to the growing diffusion of the object-oriented paradigm and the need to keep the process of software development under control, industries are looking for metrics/indicators capable of evaluating system evolution to control quality, reusability, maintainability, etc. Some new metrics are proposed for monitoring system development and maintenance. These metrics are used with a set of histograms to give a clear characterization of the system under development. Histograms call be profitably used to detect critical conditions during the system life-cycle. The semantics of these histograms has been validated against several projects: an example is also reported.

A tool for process and product assessment of C++ applications

The present diffusion of the object oriented paradigm and of the techniques for keeping the development process under control must be supported by suitable tools. These tools should be based on confident and validated object oriented metrics for assessing the several aspects of product and process development: effort, maintainability, reusability, etc.; they should also be capable of supporting the definition of specific metrics, profiles and histograms. These are useful to give the developers and managers an immediate representation of the system status. These tools must also provide metrics suitable for producing confident results from the early phases of the development life cycle. Mechanisms for metrics definition, validation and tuning must be available in order to establish a process of continuous improvement. The paper presents TAC++ (Tool for Analyzing C++ Code) which supports the above mentioned features and includes the most important metrics presented in the literature and many others.

Metrics for controlling effort during adaptive maintenance of object oriented systems

Object oriented modeling has been largely adopted in industry in the last few years. Several systems built 4 or 5 years ago may need an adaptive maintenance process in order to better satisfy market and customer needs. A model for effort estimation/prediction of the adaptive maintenance is presented. A selection of metrics for effort estimation has been applied to the general model for evaluating maintenance effort. The metrics presented have been validated against real data. The validation presented has shown that some metrics that can be profitably employed for effort estimation/prediction can be also used with success for the estimation/prediction of the maintenance effort. Moreover the results obtained give some guidelines for maintenance of control of relevant factors for adaptive maintenance.

Metrics and tool for system assessment

A wide increment of object-oriented diffusion has been registered. This is accompanied by the needs of metrics and tools for assessing class reusability, maintainability, complexity, etc. Metrics have to produce confident results and have to be continuously revalidated on the basis of the specific purpose of their adoption. Tools for system assessment must be capable of satisfying the needs of each company by supporting the definition of more specific metrics and by providing appropriate views of software characteristics. These views are useful to give the developers as well as the managers immediately understandable representations of the system status. In this paper a new approach is proposed for system assessment. This approach is based on the adoption of new and well-known metrics together with a set of histograms and profiles that give a clear characterization of the system under development. The semantics of these histograms has been validated against several projects. A brief overview of the tool, TAC++, developed for system assessment is also included.

Reengineering analysis of object-oriented systems via duplication analysis

All software systems, no matter how they are designed, are subject to continuous evolution and maintenance activities to eliminate defects and extend their functionalities. This is particularly true for object-oriented systems, where we may develop different software systems using the same internal library or framework. These systems may evolve in quite different directions in order to cover different functionalities. Typically, there is the need to analyze their evolution in order to redefine the library or framework boundaries. This is a typical problem of software reengineering analysis. In this paper, we describe metrics, based on duplication analysis, that contribute to the process of reengineering analysis of object-oriented systems. These metrics are the basic elements of a reengineering analysis method and tool. Duplication analyses at the file, class and method levels have been performed. A structural analysis using metrics that capture similarities in class structure has been also exploited. In order to identify the best approach for the reengineering analysis of object-oriented systems, a comparison between the two approaches is described. In this paper, a case study based on real cases is presented, in which the results obtained by using a reengineering process with and without the analysis tool are described. The purpose of this study is to discover which method is the most powerful and how much time reduction can be obtained by its use.

A metric framework for the assessment of object-oriented systems

In this paper an abstract of the Ph.D. thesis discussed at the University of Florence by the author is presented. The main focus of the thesis was in the identification and validation, both theoretical and empirical, of Object-Oriented metrics for complexity, and then, effort estimation. Complexity/effort metrics have been validated against test cases for verifying effectiveness of the estimation for evaluating development and maintenance effort.