A heuristic-based approach to code-smell detection

Encapsulation and data hiding are central tenets of the object oriented paradigm. Deciding what data and behaviour to form into a class and where to draw the line between its public and private details can make the difference between a class that is an understandable, flexible and reusable abstraction and one which is not. This decision is a difficult one and may easily result in poor encapsulation which can then have serious implications for a number of system qualities. It is often hard to identify such encapsulation problems within large software systems until they cause a maintenance problem (which is usually too late) and attempting to perform such analysis manually can also be tedious and error prone. Two of the common encapsulation problems that can arise as a consequence of this decomposition process are data classes and god classes. Typically, these two problems occur together – data classes are lacking in functionality that has typically been sucked into an over-complicated and domineering god class. This paper describes the architecture of a tool which automatically detects data and god classes that has been developed as a plug-in for the Eclipse IDE. The technique has been evaluated in a controlled study on two large open source systems which compare the tool results to similar work by Marinescu, who employs a metrics-based approach to detecting such features. The study provides some valuable insights into the strengths and weaknesses of the two approache

Refactoring Process Models in Large Process Repositories.

With the increasing adoption of process-aware information systems (PAIS), large process model repositories have emerged. Over time respective models have to be re-aligned to the real-world business processes through customization or adaptation. This bears the risk that model redundancies are introduced and complexity is increased. If no continuous investment is made in keeping models simple, changes are becoming increasingly costly and error-prone. Though refactoring techniques are widely used in software engineering to address related problems, this does not yet constitute state-of-the art in business process management. Process designers either have to refactor process models by hand or cannot apply respective techniques at all. This paper proposes a set of behaviour-preserving techniques for refactoring large process repositories. This enables process designers to eectively deal with model complexity by making process models better understandable and easier to maintain

Quality Assurance of Software Models - A Structured Quality Assurance Process Supported by a Flexible Tool Environment in the Eclipse Modeling Project

The paradigm of model-based software development (MBSD) has become more and more popular since it promises an increase in the efficiency and quality of software development. In this paradigm, software models play an increasingly important role and software quality and quality assurance consequently leads back to the quality and quality assurance of the involved models. The fundamental aim of this thesis is the definition of a structured syntax-oriented process for quality assurance of software models that can be adapted to project-specific and domain-specific needs. It is structured into two sub-processes: a process for the specification of project-specific model quality assurance techniques, and a process for applying them on concrete software models within a MBSD project. The approach concentrates on quality aspects to be checked on the abstract model syntax and is based on quality assurance techniques model metrics, smells, and refactorings well-known from literature. So far, these techniques are mostly considered in isolation only and therefore the proposed process integrates them in order to perform model quality assurance more systematically. Three example cases performing the process serve as proof-of-concept implementations and show its applicability, its flexibility, and hence its usefulness. Related to several issues concerning model quality assurance minor contributions of this thesis are (1) the definition of a quality model for model quality that consists of high-level quality attributes and low-level characteristics, (2) overviews on metrics, smells, and refactorings for UML class models including structured descriptions of each technique, and (3) an approach for composite model refactoring that concentrates on the specification of refactoring composition. Since manually reviewing models is time consuming and error prone, several tasks of the proposed process should consequently be automated. As a further main contribution, this thesis presents a flexible tool environment for model quality assurance which is based on the Eclipse Modeling Framework (EMF), a common open source technology in model-based software development. The tool set is part of the Eclipse Modeling Project (EMP) and belongs to the Eclipse incubation project EMF Refactor which is available under the Eclipse public license (EPL). The EMF Refactor framework supports both the model designer and the model reviewer by obtaining metrics reports, by checking for potential model deficiencies (called model smells) and by systematically restructuring models using refactorings. The functionality of EMF Refactor is integrated into standard tree-based EMF instance editors, graphical GMF-based editors as used by Papyrus UML, and textual editors provided by Xtext. Several experiments and studies show the suitability of the tools for supporting the techniques of the structured syntax-oriented model quality assurance process

Keeping the Cost of Process Change Low through Refactoring

With the increasing adoption of process-aware information systems (PAIS) large process model repositories have emerged. Over time respective models have to be re-aligned to the real world business processes through customization or adaptation. This bears the risk that model redundancies are introduced and complexity is increased. If no continuous investment is made in keeping models simple, changes are becoming increasingly costly and error-prone. Although refactoring techniques are widely used in software engineering to address related problems, this does not yet constitute state-of-the art in business process management. Consequently, process designers either have to refactor process models by hand or can not apply respective techniques at all. In this paper we propose a set of techniques for refactoring large process repositories, which are behaviour-preserving. The proposed refactorings enable process designers to effectively deal with model complexity by making process models easier to change, less error-prone and better understandable

The Impact Of Design Patterns In Refactoring Technique To Measure Performance Efficiency

Designing and developing software application has never been an easy task. The process is often time consuming and requires interaction between several different aspects. It will be harder in re-engineering the legacy system through refactoring technique, especially when consider to achieve software standard quality. Performance is one of the essential a quality attribute of software quality. Many studies in the literature have premise that design patterns improve the quality of object-oriented software systems but some studies suggest that the use of design patterns do not always result in appropriate designs. There are remaining question issues on negative or positive impacts of pattern refactoring in performance. In practice, refactoring in any part or structure of the system may take effect to another related part or structure. Effect of the process using refactoring technique and design patterns may improve software quality by making it more performable efficiency. Considerable research has been devoted in re-designing the system to improve software quality as maintainability and reliability. Less attention has been paid in measuring impact of performance efficiency quality factor. The main idea of this thesis is to investigate the impact, demonstrate how design patterns can be used to refactor the legacy software application in term of performance efficiency. It is therefore beneficial to investigate whether design patterns may influence performance of applications. In the thesis, an enterprise project named SIA (Sistem Informasi Akademik) is designed by applying Java EE platform. Some issues related to design patterns are addressed. The selection of design pattern is based on the application context issue. There are three kind of parameters measure, time behavior, resource utilization and capacity measures that based on standard guideline. We use tools support in experimentation as Apache JMeter and Java Mission Control. These tools provide convenient and generate appropriate result of performance measurement. The experiment results shown that the comparison between the legacy and refactored system that implemented design pattern indicates influence on application quality, especially on performance efficiency. ================================================================================================== Merancang dan mengembangkan aplikasi perangkat lunak bukan merupakan pekerjaan yang mudah karena membutuhkan waktu dan interaksi antara beberapa aspek. Proses desain pada rekayasa ulang akan lebih sulit meskipun melalui teknik refactoring, terutama untuk mencapai standar kualitas perangkat lunak. Kinerja merupakan salah satu atribut terpenting kualitas perangkat lunak. Banyak penelitian menjelaskan pola desain memperbaiki kualitas sistem perangkat lunak berorientasi objek, namun beberapa penelitian juga menunjukkan bahwa penggunaan pola desain tidak selalu menghasilkan desain yang sesuai. Masih ada pertanyaan tentang dampak negatif atau positif dari kinerja pola refactoring. Pada praktiknya, melakukan refactoring pada suatu bagian atau struktur sistem akan berpengaruh pada bagian atau struktur lain yang terkait. Penggunaan teknik refactoring dan pola desain dapat meningkatkan kualitas perangkat lunak dengan kinerja lebih efisien. Sudah banyak penelitian yang berfokus untuk merancang ulang sistem untuk meningkatkan kualitas perangkat lunak sebagai kemampuan rawatan dan keandalan. Tetapi masih kurang penelitian perhatian dalam mengukur dampak faktor kualitas efisiensi kinerja. Tujuan utama dalam tesis ini adalah untuk mengetahui dampaknya, menunjukkan bagaimana pola desain dapat digunakan untuk refactor aplikasi perangkat lunak terdahulu dalam hal efisiensi kinerja. Oleh karena itu, akan bermanfaat untuk menyelidiki apakah pola desain dapat mempengaruhi kinerja aplikasi. Dalam tesis ini, sebuah proyek perusahaan bernama SIA (Sistem Informasi Akademik) dirancang dengan menerapkan platform Java EE. Beberapa masalah yang terkait dengan pola desain diketahui. Pemilihan pola desain berdasarkan pada isu konteks aplikasi. Tiga jenis ukuran parameter dipakai untuk penilitian ini, perilaku waktu, pemanfaatan sumber daya dan ukuran kapasitas yang berdasarkan pada pedoman standar. Kami menggunakan Apache JMeter dan Java Mission Control sebagai alat bantu dalam eksperimen. Hasil percobaan menunjukkan bahwa perbandingan antara sistem terdahulu dengan penelitian ini yang menerapkan pola desain menunjukkan bahwa hasilnya berpengaruh terhadap kualitas aplikasi terutama pada efisiensi kinerja

On the Value of Quality Attributes for Refactoring Model Transformations Using a Multi-Objective Algorithm

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152454/1/QMOOD_for_ATL__Copy_.pd

Search‐based model transformations

Model transformations are an important cornerstone of model‐driven engineering, a discipline which facilitates the abstraction of relevant information of a system as models. The success of the final system mainly depends on the optimization of these models through model transformations. Currently, the application of transformations is realized either by following the apply‐as‐long‐as‐possible strategy or by the provision of explicit rule orchestrations. This implies two main limitations. First, the optimization objectives are implicitly hidden in the transformation rules and their orchestration. Second, manually finding the best orchestration for a particular scenario is a major challenge due to the high number of possible combinations. To overcome these limitations, we present a novel framework that builds on the non‐intrusive integration of optimization and model transformation technologies. In particular, we formulate the transformation orchestration task as an optimization problem, which allows for the efficient exploration of the transformation space and explication of the transformation objectives. Our generic framework provides several search algorithms and guides the user in providing a proper search configuration. We present different instantiations of our framework to demonstrate its feasibility, applicability, and benefits using several case studiesEuropean Commission ICT Policy Support Programme 317859Ministerio de Economia y Competitividad TIN2015-70560-RJunta de Andalucía P10-TIC-5960Junta de Andalucía P12-TIC-186

Measuring Performance Efficiency of Application applying Design Patterns and Refactoring Method

Design patterns are always useful concept using in designing and developing a software application. Performance play essential role in the quality attribute of an enterprise application. It is useful to measure and examine how design patterns influence and affect the performance of an application. In this study, we investigate the impact of selected design pattern through refactoring processes for performance efficiency. The systematic study phases included; analyzing, refactoring and performance measuring with implemented in case study SIA system. The performance measuring measure with different test cases and round for the results comparison of each differences test cases and round for design pattern indicate an influence on the performance of an applicatio