A metamodeling approach to pattern-based model refactoring

Design patterns capture development solutions to design problems in forms that make the designs more modular, modifiable, reusable, and understandable. This metamodeling approach to pattern-based refactoring of design models incorporates the precise specification of design patterns and transformation rules.     

A survey of software refactoring

We provide an extensive overview of existing research in the field of software refactoring. This research is compared and discussed based on a number of different criteria: the refactoring activities that are supported, the specific techniques and formalisms that are used for supporting these activities, the types of software artifacts that are being refactored, the important issues that need to be taken into account when building refactoring tool support, and the effect of refactoring on the software process. A running example is used to explain and illustrate the main concepts.     

Search-based refactoring for software maintenance

The high cost of software maintenance could be reduced by automatically improving the design of object-oriented programs without altering their behaviour. We have constructed a software tool capable of refactoring object-oriented programs to conform more closely to a given design quality model, by formulating the task as a search problem in the space of alternative designs. This novel approach is validated by two case studies, where programs are automatically refactored to increase flexibility, reusability and understandability as defined by a contemporary quality model. Both local and simulated annealing searches were found to be effective in this task.     

Security patterns modeling and formalization for pattern-based development of secure software systems

Pattern-based development of software systems has gained more attention recently by addressing new challenges such as security and dependability. However, there are still gaps in existing modeling languages and/or formalisms dedicated to modeling design patterns and the way how to reuse them in the automation of software development. The solution envisaged here is based on combining metamodeling techniques and formal methods to represent security patterns at two levels of abstraction to fostering reuse. The goal of the paper is to advance the state of the art in model and pattern-based security for software and systems engineering in three relevant areas: (1) develop a modeling language to support the definition of security patterns using metamodeling techniques; (2) provide a formal representation and its associated validation mechanisms for the verification of security properties; and (3) derive a set of guidelines for the modeling of security patterns within the integration of these two kinds of representations.     

On the use of many quality attributes for software refactoring: a many-objective search-based software engineering approach

Search-based software engineering (SBSE) solutions are still not scalable enough to handle high-dimensional objectives space. The majority of existing work treats software engineering problems from a single or bi-objective point of view, where the main goal is to maximize or minimize one or two objectives. However, most software engineering problems are naturally complex in which many conflicting objectives need to be optimized. Software refactoring is one of these problems involving finding a compromise between several quality attributes to improve the quality of the system while preserving the behavior. To this end, we propose a novel representation of the refactoring problem as a many-objective one where every quality attribute to improve is considered as an independent objective to be optimized. In our approach based on the recent NSGA-III algorithm, the refactoring solutions are evaluated using a set of 8 distinct objectives. We evaluated this approach on one industrial project and seven open source systems. We compared our findings to: several other many-objective techniques (IBEA, MOEA/D, GrEA, and DBEA-Eps), an existing multi-objective approach a mono-objective technique and an existing refactoring technique not based on heuristic search. Statistical analysis of our experiments over 31 runs shows the efficiency of our approach.     

A novel pattern-based approach for diagnostic controller performance monitoring

This paper details a novel method for monitoring the disturbance rejection performance of controllers by applying a second-order underdamped model as a pattern recognition tool. A controller performance index based on the second-order model parameters classifies the patterns into diagnostic categories of sluggish, well-behaved and overly aggressive. The autocorrelation function (ACF) has been used in numerous performance assessment capacities, and this work builds on these successes by applying the pattern recognition method to automate the ACF assessment across the full range of disturbance rejection performance. In addition to the performance diagnostic, a pattern-based visual tuning guide is presented for retuning PI controllers to regain desired performance. The performance assessment method has been tested on numerous control loops in a 25 MW cogeneration power plant and results of the application are presented.     

An expert system for determining candidate software classes for refactoring

In the lifetime of a software product, development costs are only the tip of the iceberg. Nearly 90% of the cost is maintenance due to error correction, adaptation and mainly enhancements. As Lehman and Belady [Lehman, M. M., & Belady, L. A. (1985). Program evolution: Processes of software change. Academic Press Professional.] state that software will become increasingly unstructured as it is changed. One way to overcome this problem is refactoring. Refactoring is an approach which reduces the software complexity by incrementally improving internal software quality. Our motivation in this research is to detect the classes that need to be rafactored by analyzing the code complexity. We propose a machine learning based model to predict classes to be refactored. We use Weighted Naïve Bayes with InfoGain heuristic as the learner and we conducted experiments with metric data that we collected from the largest GSM operator in Turkey. Our results showed that we can predict 82% of the classes that need refactoring with 13% of manual inspection effort on the average.     

A pattern-based approach to protocol mediation for web services composition

ContextWith the increasing popularity of Service Oriented Architecture (SOA), service composition is gaining momentum as the potential silver bullet for application integration. However, services are not always perfectly compatible and therefore cannot be directly composed. Service mediation, roughly classified into signature and protocol ones, thus becomes one key working area in SOA.ObjectiveAs a challenging problem, protocol mediation is still open and existing approaches only provide partial solutions. Further investigation on a systematic approach is needed.MethodsIn this paper, an approach based on mediator patterns is proposed to generate executable mediators and glue partially compatible services together. The mediation process and its main steps are introduced. By utilizing message mapping, a heuristic technique for identifying protocol mismatches and selecting appropriate mediator patterns is presented. The corresponding BPEL templates of these patterns are also developed.ResultsA prototype system, namely Service Mediation Toolkit (SMT), has been implemented to validate the feasibility and effectiveness of the proposed approach.ConclusionThe approach along with the prototype system facilitate the existing practice of protocol mediation for Web services composition.     

基于流程模式的工作流静态规划方法

现有的工作流规划方法通常对工作流执行引擎有特殊要求,使其不容易直接应用到已有的工作流系统中。针对这一问题,提出一种基于流程模式的工作流静态规划方法,通过对规划得到的工作流定义进行适配处理,使其能够直接在企业现有的工作流引擎上执行。流程定义优化让规划得到的工作流定义能够高效执行,将规划功能本身作为一个流程嵌入已有的工作流系统,使工作流规划的细节对用户透明。     

Object-oriented design: A goal-driven and pattern-based approach

In recent years, the influences of design patterns on software quality have attracted increasing attention in the area of software engineering, as design patterns encapsulate valuable knowledge to resolve design problems, and more importantly to improve the design quality. One of the key challenges in object-oriented design is how to apply appropriate design patterns during the system development. In this paper, design pattern is analyzed from different perspectives to see how it can facilitate design activities, handle non-functional requirement, solve design problems and resolve design conflicts. Based on the analysis, various kinds of applicability of design patterns are explored and integrated with a goal-driven approach to guiding developers to construct the object-oriented design model in a systematic manner. There are three benefits to the proposed approach: making it easy to meet requirements, helping resolve design conflicts, and facilitating improvement of the design quality.     

A test driven approach for aspectualizing legacy software using mock systems

Aspect-based refactoring, called aspectualization, involves moving program code that implements cross-cutting concerns into aspects. Such refactoring can improve the maintainability of legacy systems. Long compilation and weave times, and the lack of an appropriate testing methodology are two challenges to the aspectualization of large legacy systems. We propose an iterative test driven approach for creating and introducing aspects. The approach uses mock systems that enable aspect developers to quickly experiment with different pointcuts and advice, and reduce the compile and weave times. The approach also uses weave analysis, regression testing, and code coverage analysis to test the aspects. We developed several tools for unit and integration testing. We demonstrate the test driven approach in the context of large industrial C++ systems, and we provide guidelines for mock system creation.     

IPTES: A concurrent engineering approach for real-time software development

The constantly increasing concurrency, complexity, and risks associated with the industrial development of real-time embedded computer systems has been approached in different ways in recent years. In Esprit project no. EP5570, called IPTES, a methodology and a supporting environment to support the Boehm's spiral process are being developed. The prototyping environment will enable the specification, development, and verification of executable system models so that different parts of the system may represent different modeling levels and yet can be executed as a total system. Concurrent engineering problems in connection with multi-supplier, distributed software development are also addressed in the IPTES environment. In the IPTES project the concept of heterogeneous prototyping is proposed as a solution. Each of the development teams may use relatively abstract models of the other parts of the systems as a testbed (environment model) for their own part, yet they can proceed developing their own part full speed by means of advancing the maturity of their part to the next abstraction level(s). The IPTES environment provides a set of tools to help in the process of creating, analyzing, and testing distributed heterogeneous prototypes.     

An approach to prioritize code smells for refactoring

Code smells are a popular mechanism to find structural design problems in software systems. Consequently, several tools have emerged to support the detection of code smells. However, the number of smells returned by current tools usually exceeds the amount of problems that the developer can deal with, particularly when the effort available for performing refactorings is limited. Moreover, not all the code smells are equally relevant to the goals of the system or its health. This article presents a semi-automated approach that helps developers focus on the most critical problems of the system. We have developed a tool that suggests a ranking of code smells, based on a combination of three criteria, namely: past component modifications, important modifiability scenarios for the system, and relevance of the kind of smell. These criteria are complementary and enable our approach to assess the smells from different perspectives. Our approach has been evaluated in two case-studies, and the results show that the suggested code smells are useful to developers.     

Automatic software refactoring: a systematic literature review

Refactoring a software artifact is an embedded task in the maintenance phase of the software life cycle. To reduce the time and effort required for this task, researchers proposed methods to automate the software refactoring process at the design and code levels. In this paper, we conducted a systematic literature review of papers that suggest, propose, or implement an automated refactoring process. Using different phases, setting several quality measures, and snowballing, only 41 papers passed to the last stage to be analyzed and reviewed. We observe an increase in the number of papers that propose automatic refactoring. The results show that while most of the papers discuss code refactoring, only a few recent papers are focused on model refactoring. Search-based refactoring is gaining more popularity, and several researchers have used it to perform refactoring in a quick and efficient manner.     

Empirical investigation of refactoring effect on software quality

Developers and designers always strive for quality software. Quality software tends to be robust, reliable and easy to maintain, and thus reduces the cost of software development and maintenance. Several methods have been applied to improve software quality. Refactoring is one of those methods. The goal of this paper is to validate/invalidate the claims that refactoring improves software quality. We focused this study on different external quality attributes, which are adaptability, maintainability, understandability, reusability, and testability. We found that refactoring does not necessarily improve these quality attributes.     

A software engineering approach for the development of heterogeneous robotic applications

One of the most evident characteristics of robotic applications is heterogeneity: large robotic projects involve many different researchers with very different programming needs and areas of research, using a variety of hardware and software that must be integrated efficiently (i.e.: with a low development cost) to construct applications that satisfy not only classic robotic requirements (fault-tolerance, real-time specifications, intensive access to hardware, etc.) but also software engineering aspects (reusability, maintainability, etc.). Most existing solutions to this problem either do not deal with such heterogeneity or do not cover specific robotic needs. In this paper we propose a framework for the integration of heterogeneous robotic software through a software engineering approach: the BABEL development system, which is aimed to cover the main phases of the application lifecycle (design, implementation, testing, and maintainance) when unavoidable heterogeneity conditions are present. The capabilities of our system are shown by its support for designing and implementing diverse real robotic applications that use several programming languages (C, C++, JAVA), execution platforms (RT-operating systems, MS-Windows, no operating system at all), communication middleware (CORBA, TCP/IP, USB), and also a variety of hardware components (Personal Computers, microcontrollers, and a wide diversity of sensor and actuator devices in mobile robots and manipulator arms).