Developing relational navigation to effectively understand software

Effective comprehension of complex software systems requires understanding of both the individual documents that represent software and the complex relationships that exist within and between documents. Relationships of all kinds play a vital role in a software engineer's comprehension of, and navigation within and between, software documents. User-determined relationships have the additional role of enabling the engineer to create and maintain relational documentation that cannot be generated by tools or derived from other relationships. We argue that for a software development environment to effectively support the understanding of complex software systems, relational navigation must be supported at both the document-focused (intra-document) and relation-focused (inter-document) levels. The need for a relation-focused approach is highlighted by an evaluation of an existing document-focused relational interface. We conclude with the requirements for a relation-focused approach to relational navigation. These requirements focus on the user's perspective when interacting with a collection of related documents. We define the requirements for a software development environment that effectively supports the understanding of the software documents and relationships that define a complex software system.

AS PRÁTICAS DE TREINAMENTO COMO MECANISMOS DISCIPLINARES E DE REGULAÇÃO EM ORGANIZAÇÃO DE DESENVOLVIMENTO E COMÉRCIO DE SOFTWARE DE RECURSOS HUMANOS

Este trabalho tem como objetivo investigar na prática organizacional as articulações e desarticulações entre as práticas de treinamento, vistas como mecanismo que disciplina o indivíduo (normas e padronização de procedimentos de trabalho), e as diretrizes de práticas de treinamento, vistas como mecanismo de regulação (normas, padrões de conduta), das relações entre a organização e os funcionários. A pesquisa permite trazer para o ambiente acadêmico científico um aprofundamento quanto aos mecanismos de poder disciplinar exercidos pela organização estudada sobre os funcionários e os mecanismos de regulação sobre o mesmo fenômeno práticas de treinamento , além de explorar a questão da distinção e complementaridade entre ambos. Foi utilizada pesquisa qualitativa e uma proposta teóricometodológica de análise de conteúdo e análise de discurso, a partir de uma amostra indicativa e intencional, sendo a empresa do ramo de desenvolvimento e comércio de software de recursos humanos. Utilizou-se de três instrumentos para a coleta de dados: a entrevista em profundidade, observações do pesquisador e pesquisa documental. As análises feitas entre a teoria e os dados empíricos comprovaram a existência de articulações e desarticulações entre os mecanismos, além de outros achados, confirmados através da norma de treinamento e dos depoimentos dos entrevistados.

Managing software engineers and their knowledge

This chapter begins by reviewing the history of software engineering as a profession, especially the so-called software crisis and responses to it, to help focus on what it is that software engineers do. This leads into a discussion of the areas in software engineering that are problematic as a basis for considering knowledge management issues. Some of the previous work on knowledge management in software engineering is then examined, much of it not actually going under a knowledge management title, but rather “learning” or “expertise”. The chapter goes on to consider the potential for knowledge management in software engineering and the different types of knowledge management solutions and strategies that might be adopted, and it touches on the crucial importance of cultural issues. It concludes with a list of challenges that knowledge management in software engineering needs to address.

Linking the witness simulation software to an expert system to represent a decision-making process

Expert systems, and artificial intelligence more generally, can provide a useful means for representing decision-making processes. By linking expert systems software to simulation software an effective means of including these decision-making processes in a simulation model can be achieved. This paper demonstrates how a commercial-off-the-shelf simulation package (Witness) can be linked to an expert systems package (XpertRule) through a Visual Basic interface. The methodology adopted could be used for models, and possibly software, other than those presented here.

A design environment for deadlock-free concurrent software

Using current software engineering technology, the robustness required for safety critical software is not assurable. However, different approaches are possible which can help to assure software robustness to some extent. For achieving high reliability software, methods should be adopted which avoid introducing faults (fault avoidance); then testing should be carried out to identify any faults which persist (error removal). Finally, techniques should be used which allow any undetected faults to be tolerated (fault tolerance). The verification of correctness in system design specification and performance analysis of the model, are the basic issues in concurrent systems. In this context, modeling distributed concurrent software is one of the most important activities in the software life cycle, and communication analysis is a primary consideration to achieve reliability and safety. By and large fault avoidance requires human analysis which is error prone; by reducing human involvement in the tedious aspect of modelling and analysis of the software it is hoped that fewer faults will persist into its implementation in the real-time environment. The Occam language supports concurrent programming and is a language where interprocess interaction takes place by communications. This may lead to deadlock due to communication failure. Proper systematic methods must be adopted in the design of concurrent software for distributed computing systems if the communication structure is to be free of pathologies, such as deadlock. The objective of this thesis is to provide a design environment which ensures that processes are free from deadlock. A software tool was designed and used to facilitate the production of fault-tolerant software for distributed concurrent systems. Where Occam is used as a design language then state space methods, such as Petri-nets, can be used in analysis and simulation to determine the dynamic behaviour of the software, and to identify structures which may be prone to deadlock so that they may be eliminated from the design before the program is ever run. This design software tool consists of two parts. One takes an input program and translates it into a mathematical model (Petri-net), which is used for modeling and analysis of the concurrent software. The second part is the Petri-net simulator that takes the translated program as its input and starts simulation to generate the reachability tree. The tree identifies `deadlock potential' which the user can explore further. Finally, the software tool has been applied to a number of Occam programs. Two examples were taken to show how the tool works in the early design phase for fault prevention before the program is ever run.

Software engineering techniques for the development of systems of systems

This paper investigates how existing software engineering techniques can be employed, adapted and integrated for the development of systems of systems. Starting from existing system-of-systems (SoS) studies, we identify computing paradigms and techniques that have the potential to help address the challenges associated with SoS development, and propose an SoS development framework that combines these techniques in a novel way. This framework addresses the development of a class of IT systems of systems characterised by high variability in the types of interactions between their component systems, and by relatively small numbers of such interactions. We describe how the framework supports the dynamic, automated generation of the system interfaces required to achieve these interactions, and present a case study illustrating the development of a data-centre SoS using the new framework.

FlexSIG-Flexible software inspection groupware

The objective of this research is to design and build a groupware system which will allow members of a distributed group more flexibility in performing software inspection. Software inspection, which is part of non-execution based testing in software development, is a group activity. The groupware system aims to provide a system that will improve acceptability of groupware and improve software quality by providing a software inspection tool that is flexible and adaptable. The groupware system provide a flexible structure for software inspection meetings. The groupware system will extend the structure of the software inspection meeting itself, allowing software inspection meetings to use all four quadrant of the space-time matrix: face-to-face, distributed synchronous, distributed asynchronous, and same place-different time. This will open up new working possibilities. The flexibility and adaptability of the system allows work to switch rapidly between synchronous and asynchronous interaction. A model for a flexible groupware system was developed. The model was developed based on review of the literature and questionnaires. A prototype based on the model was built using java and WWW technology. To test the effectiveness of the system, an evaluation was conducted. Questionnaires was used to gather response from the users. The evaluations ascertained that the model developed is flexible and adaptable to the different working modes, and the system is capable of supporting several different models of the software inspection process.

The design of fault tolerant software for loosely coupled distributed systems

Requirements for systems to continue to operate satisfactorily in the presence of faults has led to the development of techniques for the construction of fault tolerant software. This thesis addresses the problem of error detection and recovery in distributed systems which consist of a set of communicating sequential processes. A method is presented for the `a priori' design of conversations for this class of distributed system. Petri nets are used to represent the state and to solve state reachability problems for concurrent systems. The dynamic behaviour of the system can be characterised by a state-change table derived from the state reachability tree. Systematic conversation generation is possible by defining a closed boundary on any branch of the state-change table. By relating the state-change table to process attributes it ensures all necessary processes are included in the conversation. The method also ensures properly nested conversations. An implementation of the conversation scheme using the concurrent language occam is proposed. The structure of the conversation is defined using the special features of occam. The proposed implementation gives a structure which is independent of the application and is independent of the number of processes involved. Finally, the integrity of inter-process communications is investigated. The basic communication primitives used in message passing systems are seen to have deficiencies when applied to systems with safety implications. Using a Petri net model a boundary for a time-out mechanism is proposed which will increase the integrity of a system which involves inter-process communications.

A semantic modelling approach to knowledge based statistical software

The topic of this thesis is the development of knowledge based statistical software. The shortcomings of conventional statistical packages are discussed to illustrate the need to develop software which is able to exhibit a greater degree of statistical expertise, thereby reducing the misuse of statistical methods by those not well versed in the art of statistical analysis. Some of the issues involved in the development of knowledge based software are presented and a review is given of some of the systems that have been developed so far. The majority of these have moved away from conventional architectures by adopting what can be termed an expert systems approach. The thesis then proposes an approach which is based upon the concept of semantic modelling. By representing some of the semantic meaning of data, it is conceived that a system could examine a request to apply a statistical technique and check if the use of the chosen technique was semantically sound, i.e. will the results obtained be meaningful. Current systems, in contrast, can only perform what can be considered as syntactic checks. The prototype system that has been implemented to explore the feasibility of such an approach is presented, the system has been designed as an enhanced variant of a conventional style statistical package. This involved developing a semantic data model to represent some of the statistically relevant knowledge about data and identifying sets of requirements that should be met for the application of the statistical techniques to be valid. Those areas of statistics covered in the prototype are measures of association and tests of location.

An operational approach to object-oriented software development

The traditional waterfall software life cycle model has several weaknesses. One problem is that a working version of a system is unavailable until a late stage in the development; any omissions and mistakes in the specification undetected until that stage can be costly to maintain. The operational approach which emphasises the construction of executable specifications can help to remedy this problem. An operational specification may be exercised to generate the behaviours of the specified system, thereby serving as a prototype to facilitate early validation of the system's functional requirements. Recent ideas have centred on using an existing operational method such as JSD in the specification phase of object-oriented development. An explicit transformation phase following specification is necessary in this approach because differences in abstractions between the two domains need to be bridged. This research explores an alternative approach of developing an operational specification method specifically for object-oriented development. By incorporating object-oriented concepts in operational specifications, the specifications have the advantage of directly facilitating implementation in an object-oriented language without requiring further significant transformations. In addition, object-oriented concepts can help the developer manage the complexity of the problem domain specification, whilst providing the user with a specification that closely reflects the real world and so the specification and its execution can be readily understood and validated. A graphical notation has been developed for the specification method which can capture the dynamic properties of an object-oriented system. A tool has also been implemented comprising an editor to facilitate the input of specifications, and an interpreter which can execute the specifications and graphically animate the behaviours of the specified systems.

An Exploration of parametric software cost estimating models for Jackson Systems Development

Most parametric software cost estimation models used today evolved in the late 70's and early 80's. At that time, the dominant software development techniques being used were the early 'structured methods'. Since then, several new systems development paradigms and methods have emerged, one being Jackson Systems Development (JSD). As current cost estimating methods do not take account of these developments, their non-universality means they cannot provide adequate estimates of effort and hence cost. In order to address these shortcomings two new estimation methods have been developed for JSD projects. One of these methods JSD-FPA, is a top-down estimating method, based on the existing MKII function point method. The other method, JSD-COCOMO, is a sizing technique which sizes a project, in terms of lines of code, from the process structure diagrams and thus provides an input to the traditional COCOMO method.The JSD-FPA method allows JSD projects in both the real-time and scientific application areas to be costed, as well as the commercial information systems applications to which FPA is usually applied. The method is based upon a three-dimensional view of a system specification as opposed to the largely data-oriented view traditionally used by FPA. The method uses counts of various attributes of a JSD specification to develop a metric which provides an indication of the size of the system to be developed. This size metric is then transformed into an estimate of effort by calculating past project productivity and utilising this figure to predict the effort and hence cost of a future project. The effort estimates produced were validated by comparing them against the effort figures for six actual projects.The JSD-COCOMO method uses counts of the levels in a process structure chart as the input to an empirically derived model which transforms them into an estimate of delivered source code instructions.

Neural network enhanced self tuning adaptive control application for non-linear control of dynamic systems

The main theme of research of this project concerns the study of neutral networks to control uncertain and non-linear control systems. This involves the control of continuous time, discrete time, hybrid and stochastic systems with input, state or output constraints by ensuring good performances. A great part of this project is devoted to the opening of frontiers between several mathematical and engineering approaches in order to tackle complex but very common non-linear control problems. The objectives are: 1. Design and develop procedures for neutral network enhanced self-tuning adaptive non-linear control systems; 2. To design, as a general procedure, neural network generalised minimum variance self-tuning controller for non-linear dynamic plants (Integration of neural network mapping with generalised minimum variance self-tuning controller strategies); 3. To develop a software package to evaluate control system performances using Matlab, Simulink and Neural Network toolbox. An adaptive control algorithm utilising a recurrent network as a model of a partial unknown non-linear plant with unmeasurable state is proposed. Appropriately, it appears that structured recurrent neural networks can provide conveniently parameterised dynamic models for many non-linear systems for use in adaptive control. Properties of static neural networks, which enabled successful design of stable adaptive control in the state feedback case, are also identified. A survey of the existing results is presented which puts them in a systematic framework showing their relation to classical self-tuning adaptive control application of neural control to a SISO/MIMO control. Simulation results demonstrate that the self-tuning design methods may be practically applicable to a reasonably large class of unknown linear and non-linear dynamic control systems.