Of An Object-oriented Research Articles

Class Complexity Metric to Predict Understandability

This paper presents a new class complexity metric of an Object-Oriented (OO) program which is used to predict the understandability of classes. The propose complexity metric is evaluated theoretically against Weyuker's properties to analyze the nature of metric and empirically evaluated against three small projects developed by Post Graduate (PG)/Under Graduate (UG) teams. Least Square Regression Analysis technique is performed to arrive at the result and find correlation coefficient of propose metric with the Degree of Understandability. The result indicates that the propose metric is a good predictor of understandability of classes. JHAWK TOOL (Java Code Metrics Tool) were used to evaluate the parameters values involved in propose metric and for analyzing the results of projects, Matlab6.1 and IBM SPSS software were used.

An object-oriented approach for modelling and simulation of construction operations

This paper describes the application of an object-oriented (OO) modelling concept and OO programming mechanisms to develop an activity object-oriented (AOO) simulation strategy for modelling construction operations. The AOO simulation strategy considers construction activities to be objects, thus overcoming some pitfalls due to the general simulation strategies in developing simulation models or controlling simulation experiments. This paper also discusses the characteristics and related problems of some simulation strategies used for construction simulation. Moreover, the AOO graphical modelling interface associated with the AOO simulation strategy is described. Finally, the AOO simulation system has been compared with other simulation tools.

Activity Object-Oriented Simulation Strategy for Modeling Construction Operations

The application of an object-oriented (OO) approach including the OO modeling concept and the OO programming mechanisms to develop an activity object-oriented (AOO) simulation strategy for modeling construction operations is introduced. After discussing simulation strategies generally used for construction simulation and analyzing the problems related to the simulation strategies, the AOO simulation strategy that guides modeling or controls simulation experiments for construction simulation is introduced. The AOO simulation strategy considers activities to be objects and is able to overcome some pitfalls that result from other general simulation strategies. In addition, the AOO graphical modeling interface associated with the AOO simulation strategy is described. Finally, comparisons of the graphical model or the simulation results of the AOO simulation system with other simulation tools are illustrated.

Object-oriented framework for durability assessment and life cycle costing of highway bridges

Design professionals are increasingly faced with challenges to produce innovative designs that are durable and give good value for money to clients. However, durability is impinged upon by the interaction of different factors such as construction materials, construction method, quality systems in use at the construction stages, environmental exposure of the structural elements and their functions, ease of access for inspection and maintenance. It is therefore necessary to investigate frameworks that address the above outlined factors, for use by construction professionals. The framework should integrate the outlined durability factors and facilitate achieving the objectives of durability design that account for life cycle costs and sustainability of design options, rather than just focusing on the initial design and construction cost. This paper highlights the application of an object-oriented (OO) framework to decision-making in designing for durability in the bridge domain, and a prototype implementation of this framework. It discusses how an object-based solution could contribute towards achieving the objectives of durability and minimum maintenance costs at project level. The paper also gives recommendations for further work.

DESIGN LEVEL HYPOTHESIS TESTING THROUGH REVERSE ENGINEERING OF OBJECT-ORIENTED SOFTWARE

Comprehension of an object-oriented (OO) system, its design and use of OO features such as aggregation, generalisation and other forms of association is a difficult task to undertake without the original design documentation for reference. In this paper, we describe the collection of high-level class metrics from the UML design documentation of five industrial-sized C++ systems. Two of the systems studied were libraries of reusable classes. Three hypotheses were tested between these high-level features and the low-level class features of a number of class methods and attributes in each of the five systems. A further two conjectures were then investigated to determine features of key classes in a system and to investigate any differences between library-based systems and the other systems studied in terms of coupling. Results indicated that, for the three application-based systems, no clear patterns emerged for hypotheses relating to generalisation. There was, however, a clear (positive) statistical significance for all three systems studied between aggregation, other types of association and the number of methods and attributes in a class. Key classes in the three application-based systems tended to contain large numbers of methods, attributes, and associations, significant amounts of aggregation but little inheritance. No consistent, identifiable key features could be found in the two library-based systems; both showed a distinct lack of any form of coupling (including inheritance) other than through the C++ friend facility.

An empirical study of system design instability metric and design evolution in an agile software process

Software project tracking and project plan adjustment are two important software engineering activities. The class growth shows the design evolution of the software. The System Design Instability (SDI) metric indicates the progress of an object-oriented (OO) project once the project is set in motion. The SDI metric provides information on project evolution to project managers for possible adjustment to the project plan. The objectives of this paper are to test if the System Design Instability metric can be used to estimate and re-plan software projects in an XP-like agile process and study system design evolution in the Agile software process. We present an empirical study of the class growth and the SDI metric in two OO systems, developed using an agile process similar to Extreme Programming (XP). We analyzed the system evolutionary data collected on a daily basis from the two systems. We concluded that: the systems' class growth follows observable trends, the SDI metric can indicate project progress with certain trends, and the SDI metric is correlated with XP activities. In both of the analyzed systems, we observed two consistent jumps in the SDI metric values in early and late development phases. Part of the results agrees with a previous empirical study in another environment.

A change impact model for changeability assessment in object-oriented software systems

Growing maintenance costs have become a major concern for developers and users of software systems. Changeability is an important aspect of maintainability, especially in environments where software changes are frequently required. In this work, the assumption that high-level design has an influence on maintainability is carried over to changeability and investigated for that quality characteristics. The approach taken to assess the changeability of an object-oriented (OO) system is to compute the impact of changes made to classes of the system. A change impact model is defined at the conceptual level and mapped on the C++ language. In order to experiment the model as a changeability indicator on large industrial software systems, an experiment involving the impact of one change is carried out on a telecommunications system. The results suggest that the software can easily absorb that kind of change and that well chosen conventional OO design metrics can be used as indicators of changeability.

Object-orientated design of digital library platforms for multiagent environments

The application of an object-oriented (OO) methodology to the design of a platform for heterogeneous digital libraries with multiagent technologies is demonstrated. Emphasis is placed on maximizing the autonomy of the query processing activity. The Fusion OO paradigm is specifically employed as the basis for the design process due to the significance attributed to the development of object interfaces under static and dynamic conditions. Finally, characteristics of the proposed Domain Index Server (DIS) platform are contrasted with those of an alternative platform (the University of Michigan Digital Library, UMDL) by way of the respective Fusion descriptions. This identifies a different emphasis on the interface design between objects in the two platforms: the DIS system uses more dynamic links while the UMDL system focuses on permanent and constant links. Simulation of the two platforms provides performance data that demonstrates the higher capacity of the DIS scheme.

Module interconnection features in object-oriented development tools

The black-box reuse of library classes in the construction of an object-oriented (OO) application is difficult: the principle of information hiding may be violated if classes must know their partners, and code must be typically rewritten. One of the possible ways to increase class decoupling and thus reuse is to employ interconnection languages to describe OO architectures. In this paper we present a decoupling paradigm for individual classes or class collections that facilitates reuse, introducing interconnection features at the design and programming levels. We give examples in a new, second generation OO development system, using asynchronous messages sent to generically identified receivers.

Integrated information modelling for CIM

The development of strategic plans for the stepwise introduction of computer integrated manufacturing requires models and modelling techniques to describe the business processes, functions and the required data and their relation to the desired system components. Several modelling methods have been analyzed. The fundamental deficiency is the missing integration between the process and the data models from the enterprise viewpoint. The paper shows the key issues of an object-oriented (OO) modelling method which can be used for CIM-planning as well as for the integration of CIM-standards, e.g. STEP, which are currently under development in European and international commities. The main OO-features like encapsulation, inheritance and the class concept were used to describe enterprise object-classes and the process which change the instances of these classes. The feature-structure of the object classes and the aggregation to complete models were shown.