Software visualisation for object-oriented program comprehension

Software visualisation is the process of modelling software systems for comprehension. The comprehension of software systems both during and after development is a crucial component of the software process. The complex interactions inherent in the object-oriented paradigm make visualisation a particularly appropriate comprehension technique, and the large volume of information typically generated during visualisation necessitates tool support

Towards more accurate real time testing

The languages Message Sequence Charts (MSC) [1], System Design Language1 (SDL) [2] and Testing and Test Control Notation Testing2 (TTCN-3) [3] have been developed for the design, modelling and testing of complex software systems. These languages have been developed to complement one another in the software development process. Each of these languages has features for describing, analysing or testing the real time properties of systems. Robust toolsets exist which provide integrated environments for the design, analysis and testing of systems, and it is claimed, for the complete development of real time systems. It was shown in [4] however, that there are fundamental problems with the SDL language and its associated tools for modelling and reasoning about real time systems. In this paper we present the limitations of TTCN-3 and propose recommendations which help minimise the timing inaccuracies that would otherwise occur in using the language directly

TES: A modular systems approach to expert system development for real-time space applications

A major goal of the Space Station era is to reduce reliance on support from ground based experts. The development of software programs using expert systems technology is one means of reaching this goal without requiring crew members to become intimately familiar with the many complex spacecraft subsystems. Development of an expert systems program requires a validation of the software with actual flight hardware. By combining accurate hardware and software modelling techniques with a modular systems approach to expert systems development, the validation of these software programs can be successfully completed with minimum risk and effort. The TIMES Expert System (TES) is an application that monitors and evaluates real time data to perform fault detection and fault isolation tasks as they would otherwise be carried out by a knowledgeable designer. The development process and primary features of TES, a modular systems approach, and the lessons learned are discussed

The Educational Value of Modelling Complex Thermodynamic Systems with System Dynamics Software

The solution of problems involving complex thermodynamic systems often occupies much of a students\u27 time and can be a distraction from them developing a clear understanding of system components, interaction of subsystems, modelling simplifications and assumptions, and design optimization. Refocusing students on the fundamental concepts of thermal systems design and analysis is possible with the introduction of system modelling software that carries some of the load of repetitive calculation required for complex systems. Models of thermodynamic systems encountered in an advanced undergraduate thermodynamics course were developed by students (some provided to students) to solve homework problems of complex steam power plants, internal combustion engines, gas turbine power plants, refrigeration, and building energy systems. Computer modelling systems used included two commercial modelling programs, an open source program, and systems developed by the authors. Use of the modelling software forced students to setup problems in the same way as if solved on paper but allowed them to identify common components and processes that could be modeled by common blocks and used in multiple thermal systems. One example presented is a simple process block that gives the state for any location in a converging/diverging supersonic nozzle with a normal shock. The initial implementation has resulted in positive feedback from students and an improved self-efficacy in understanding and modelling complex thermodynamic systems not presented in class

An introduction to the Cambridge advanced modeller

Complex products and their development processes may be viewed as systems, whose different aspects can be modelled as networks of interactions between elements in different domains. Many approaches have been proposed to explore, support or improve engineering processes by building such models. Developing these approaches, and applying them to problems of realistic complexity, often requires specialised computer software suitable for manipulating large data sets. However, creating suitable tools can be difficult–because software development is time-consuming and requires skills that many researchers and practitioners do not possess. We developed an approach which aims to address this problem by recognising the iterative nature of modelling research and its often tight coupling with prototype software development, and by reducing the effort of software prototyping and revision within this process. The approach is enabled by, and embodied in, the Cambridge Advanced Modeller (CAM)–a configurable software platform we have developed, refined and applied over several years and through a number of research projects

Kernel arquitecture for CAD/CAM in shipbuilding enviroments

The capabilities of complex software products such as CAD/CAM systems are strongly supported by basic information technologies related with data management, visualization, communication, geometry modeling and others related with the development process. These basic information technologies are involved in a continuous evolution process, but over recent years this evolution has been dramatic. The main reason for this has been that new hardware capabilities (including graphic cards) are available at very low cost, but also a contributing factor has been the evolution of the prices of basic software. To take advantage of these new features, the existing CAD/CAM systems must undergo a complete and drastic redesign. This process is complicated but strategic for the future evolution of a system. There are several examples in the market of how a bad decision has lead to a cul-de-sac (both technically and commercially). This paper describes what the authors consider are the basic architectural components of a kernel for a CAD/CAM system oriented to shipbuilding. The proposed solution is a combination of in-house developed frameworks together with commercial products that are accepted as standard components. The proportion of in-house frameworks within this combination of products is a key factor, especially when considering CAD/CAM systems oriented to shipbuilding. General-purpose CAD/CAM systems are mainly oriented to the mechanical CAD market. For this reason several basic products exist devoted to geometry modelling in this context. But these basic products are not well suited to deal with the very specific geometry modelling requirements of a CAD/CAM system oriented to shipbuilding. The complexity of the ship model, the different model requirements through its short and changing life cycle and the many different disciplines involved in the process are reasons for this inadequacy. Apart from these basic frameworks, specific shipbuilding frameworks are also required. This second layer is built over the basic technology components mentioned above. This paper describes in detail the technological frameworks which have been used to develop the latest FORAN version.Postprint (published version

Printing Process Parameters Identification System

The paper presents the research aimed at setting up and developing a software system for the printing process parameters identification based on modern computer and software systems, algorithmic principles, principles of expert systems construction and advanced learning. Thus, the possibilities of application of contemporary software tools were investigated, which facilitates the process and forms the program structure of the model that uses programming languages based on the expert systems construction principles and tools for the development of system model based on the principles of modern learning. For complex model development, concepts of process knowledge bases with influential process parameters of printing technique have been developed through modelling and construction based on the logic of expert systems with the presentation, use and involvement of experts knowledge in decision making with the evaluation of the impact of individual parameters. In addition to this approach, a module was developed using modern software tools based on an algorithmic principle and a module for identifying printing process parameters using modern platforms based on advanced learning. Sophisticated software model has been made through the research and developed with databases of process parameter identification systems based on modern software tools. This tool enables a significant expedition of the solution resolving, thus improving the graphical production process and the processes of acquiring and expanding knowledge. The model is based on integrative modules: a printing process parameters identification system based on algorithmic program structure systems, a printing process parameters identification system based on expert system building principles, and a printing process parameter identification system based on modern learning systems

Community care system design and development with AUML

An approach to the development of an appropriate agent environment is described in which software researchers collaborate with environment builders to enhance the levels of cooperation and support provided within an integrated agent-oriented community system. Agent-oriented Unified Modelling Language (AUML) is a practical approach to the analysis, design, implementation and management of such a software agent system, whilst providing the power and expressiveness necessary to support the specification, design and organisation of a health care service. This paper describes the background of agent-based health care and the fundamental concepts of Agentoriented UML and outlines how this refreshing approach can be used in the analysis, design, development and organization of agent-based community health care systems. Our approach to building agent-oriented software development solutions emphasizes the importance of AUML as a fundamental initial step in producing agent-based architectures and applications. This approach aims to present an effective schedule and methodology for an agent software development process, by addressing the complex agent environments decomposition, abstraction, organization and software development process activities characteristics, whilst reducing the complexity of the complex agent systems' design and development by using and exploiting AUML's productivity potential

Feature Nets: behavioural modelling of software product lines

Software product lines (SPL) are diverse systems that are developed using a dual engineering process: (a)family engineering defines the commonality and variability among all members of the SPL, and (b) application engineering derives specific products based on the common foundation combined with a variable selection of features. The number of derivable products in an SPL can thus be exponential in the number of features. This inherent complexity poses two main challenges when it comes to modelling: Firstly, the formalism used for modelling SPLs needs to be modular and scalable. Secondly, it should ensure that all products behave correctly by providing the ability to analyse and verify complex models efficiently. In this paper we propose to integrate an established modelling formalism (Petri nets) with the domain of software product line engineering. To this end we extend Petri nets to Feature Nets. While Petri nets provide a framework for formally modelling and verifying single software systems, Feature Nets offer the same sort of benefits for software product lines. We show how SPLs can be modelled in an incremental, modular fashion using Feature Nets, provide a Feature Nets variant that supports modelling dynamic SPLs, and propose an analysis method for SPL modelled as Feature Nets. By facilitating the construction of a single model that includes the various behaviours exhibited by the products in an SPL, we make a significant step towards efficient and practical quality assurance methods for software product lines