48,640 research outputs found
Dynamic Coupling Measurement for Object-Oriented Software
A major goal of software engineering research is to develop
techniques, methods and tools that may improve software quality. This
thesis contributes to that goal.
It is possible to assume two different views on quality as it relates
to software products. In the external view, quality is determined
based on how well a product performs in practise, i.e.,
maintainability and usability. In the internal view, quality is
derived from attributes inherent in the software product, e.g.,
structural properties such as coupling, cohesion and size.
Much research related to software quality models has focused on
establishing relationships between structural properties and external
quality attributes. The ultimate goal of this research is to develop
quality prediction models, which may aid in making informed decisions
concerning, for example, refactoring or program design.
Regardless of the structural properties considered, most quality
prediction models have so far been based on static analysis of source
code or designs. Such models have proven to be fairly accurate on
some occasions. However, in the context of object-oriented systems,
static coupling measures may not always be accurate, thus resulting in
unreliable prediction models. Due to polymorphism and dynamic binding,
static coupling measures do not always reflect the actual coupling
taking place between classes, as this can only be determined at
run-time. In addition, static measurements of coupling may be
inaccurate when obtained from systems containing ``dead'' code.
In an attempt to overcome these problems, twelve dynamic coupling
measures have been proposed. They differ from static coupling measures
in that they are based on analysis of the actual messages exchanged
between objects at run-time. The twelve measures are therefore
referred to as ``dynamic coupling measures''. To collect the dynamic
coupling measures, a tool called Jdissect was developed. Jdissect
collects data from running Java programs to calculate dynamic
coupling.
There are three objectives for the investigation of the proposed
coupling measures. The measures need to be theoretically validated,
that is, one needs to assess their theoretical properties and validity
as coupling measures. Furthermore, it is important to determine
whether they provide data over and above what can be collected through
static measures such as size and static coupling. Finally, to
demonstrate practical usefulness of the dynamic coupling measures,
they must be evaluated as predictors of external quality. In the case
study presented in this thesis, the external quality attribute
considered for the evaluation is change proneness, which is an
indirect measure of software maintainability.
The results indicate that some of the dynamic coupling measures are
strong indicators of change proneness and that they complement
existing static measures. The resulting prediction models may, for
example, be useful to focus restructuring efforts on those parts of
the software that are predicted to be the most likely to undergo
future changes
Quantifying Structural Attributes of System Decompositions in 28 Feature-oriented Software Product Lines: An Exploratory Study
Background: A key idea of feature orientation is to decompose a software product line along the features it provides. Feature decomposition is orthogonal to object-oriented decomposition it crosscuts the underlying package and class structure. It has been argued often that feature decomposition improves system structure (reduced coupling, increased cohesion). However, recent empirical findings suggest that this is not necessarily the case, which is the motivation for our empirical investigation.
Aim: In fact, there is little empirical evidence on how the alternative decompositions of feature orientation and object orientation compare to each other in terms of their association with observable properties of system structure (coupling, cohesion). This motivated us to empirically investigate and compare the properties of three decompositions (object-oriented, feature-oriented, and their intersection) of 28 feature-oriented software product lines.
Method: In an exploratory, observational study, we quantify internal attributes, such as import coupling and cohesion, to describe and analyze the different decompositions of a feature-oriented product line in a systematic, reproducible, and comparable manner. For this purpose, we use three established software measures (CBU, IUD, EUD) as well as standard distribution statistics (e.g., Gini coefficient).
Results: First, feature decomposition is associated with higher levels of structural coupling in a product line than a decomposition into classes. Second, although coupling is concentrated in feature decompositions, there are not necessarily hot-spot features. Third, the cohesion of feature modules is not necessarily higher than class cohesion, whereas feature modules serve more dependencies internally than classes. Fourth, coupling and cohesion measurement show potential for sampling optimization in complex static and dynamic product-line analyses (product-line type checking, feature-interaction detection).
Conclusions: Our empirical study raises critical questions about alleged advantages of feature decomposition. At the same time, we demonstrate how the measurement of structural attributes can facilitate static and dynamic analyses of software product lines. (authors' abstract)Series: Technical Reports / Institute for Information Systems and New Medi
A Parsing Scheme for Finding the Design Pattern and Reducing the Development Cost of Reusable Object Oriented Software
Because of the importance of object oriented methodologies, the research in
developing new measure for object oriented system development is getting
increased focus. The most of the metrics need to find the interactions between
the objects and modules for developing necessary metric and an influential
software measure that is attracting the software developers, designers and
researchers. In this paper a new interactions are defined for object oriented
system. Using these interactions, a parser is developed to analyze the existing
architecture of the software. Within the design model, it is necessary for
design classes to collaborate with one another. However, collaboration should
be kept to an acceptable minimum i.e. better designing practice will introduce
low coupling. If a design model is highly coupled, the system is difficult to
implement, to test and to maintain overtime. In case of enhancing software, we
need to introduce or remove module and in that case coupling is the most
important factor to be considered because unnecessary coupling may make the
system unstable and may cause reduction in the system's performance. So
coupling is thought to be a desirable goal in software construction, leading to
better values for external software qualities such as maintainability,
reusability and so on. To test this hypothesis, a good measure of class
coupling is needed. In this paper, based on the developed tool called Design
Analyzer we propose a methodology to reuse an existing system with the
objective of enhancing an existing Object oriented system keeping the coupling
as low as possible.Comment: 15 page
The C Object System: Using C as a High-Level Object-Oriented Language
The C Object System (Cos) is a small C library which implements high-level
concepts available in Clos, Objc and other object-oriented programming
languages: uniform object model (class, meta-class and property-metaclass),
generic functions, multi-methods, delegation, properties, exceptions, contracts
and closures. Cos relies on the programmable capabilities of the C programming
language to extend its syntax and to implement the aforementioned concepts as
first-class objects. Cos aims at satisfying several general principles like
simplicity, extensibility, reusability, efficiency and portability which are
rarely met in a single programming language. Its design is tuned to provide
efficient and portable implementation of message multi-dispatch and message
multi-forwarding which are the heart of code extensibility and reusability.
With COS features in hand, software should become as flexible and extensible as
with scripting languages and as efficient and portable as expected with C
programming. Likewise, Cos concepts should significantly simplify adaptive and
aspect-oriented programming as well as distributed and service-oriented
computingComment: 18
Assessing architectural evolution: A case study
This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2011 SpringerThis paper proposes to use a historical perspective on generic laws, principles,
and guidelines, like Lehman’s software evolution laws and Martin’s design principles, in order to achieve a multi-faceted process and structural assessment of a system’s architectural evolution. We present a simple structural model with associated historical metrics and
visualizations that could form part of an architect’s dashboard. We perform such an assessment for the Eclipse SDK, as a case study of a large, complex, and long-lived system for which sustained effective architectural evolution is paramount. The twofold aim of checking generic principles on a well-know system is, on the one hand,
to see whether there are certain lessons that could be learned for best practice of architectural evolution, and on the other hand to get more insights about the applicability of such principles. We find that while the Eclipse SDK does follow several of the laws and principles, there are some deviations, and we discuss areas of architectural improvement and limitations of the assessment approach
Modeling the object-oriented software process: OPEN and the unified process
A short introduction to software process modeling is presented, particularly object-oriented modeling. Two major industrial process models are discussed: the OPEN model and the Unified Process model. In more detail, the quality assurance in the Unified Process tool (formally called Objectory) is reviewed
DISTANCE: a framework for software measure construction.
In this paper we present a framework for software measurement that is specifically suited to satisfy the measurement needs of empirical software engineering research. The framework offers an approach to measurement that builds upon the easily imagined, detected and visualised concepts of similarity and dissimilarity between software entities. These concepts are used both to model the software attributes of interest and to define the corresponding software measures. Central to the framework is a process model that embeds constructive procedures for attribute modelling and measure construction into a goal-oriented approach to empirical software engineering studies. The underlying measurement theoretic principles of our approach ensure the construct validity of the resulting measures. The approach was tested on a popular suite of object-oriented design measures. We further show that our measure construction method compares favourably to related work.Software;
Structural Complexity and Decay in FLOSS Systems: An Inter-Repository Study
Past software engineering literature has firmly established that software architectures and the associated code decay over time. Architectural decay is, potentially, a major issue in Free/Libre/Open Source Software (FLOSS) projects, since developers sporadically joining FLOSS projects do not always have a clear understanding of the underlying architecture, and may break the overall conceptual structure by several small changes to the code base.
This paper investigates whether the structure of a FLOSS system and its decay can also be influenced by the repository in which it is retained: specifically,
two FLOSS repositories are studied to understand whether the complexity of the software structure in the sampled projects is comparable, or one repository hosts more complex systems than the other. It is also studied
whether the effort to counteract this complexity is dependent on the repository, and the governance it gives to the hosted projects.
The results of the paper are two-fold: on one side, it is shown that the repository hosting larger and more active projects presents more complex structures. On the other side, these larger and more complex systems benefit
from more anti-regressive work to reduce this complexity
A framework for the simulation of structural software evolution
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 ACM.As functionality is added to an aging piece of software, its original design and structure will tend to erode. This can lead to high coupling, low cohesion and other undesirable effects associated with spaghetti architectures. The underlying forces that cause such degradation have been the subject of much research. However, progress in this field is slow, as its complexity makes it difficult to isolate the causal flows leading to these effects. This is further complicated by the difficulty of generating enough empirical data, in sufficient quantity, and attributing such data to specific points in the causal chain. This article describes a framework for simulating the structural evolution of software. A complete simulation model is built by incrementally adding modules to the framework, each of which contributes an individual evolutionary effect. These effects are then combined to form a multifaceted simulation that evolves a fictitious code base in a manner approximating real-world behavior. We describe the underlying principles and structures of our framework from a theoretical and user perspective; a validation of a simple set of evolutionary parameters is then provided and three empirical software studies generated from open-source software (OSS) are used to support claims and generated results. The research illustrates how simulation can be used to investigate a complex and under-researched area of the development cycle. It also shows the value of incorporating certain human traits into a simulation—factors that, in real-world system development, can significantly influence evolutionary structures
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