Modelling software quality in the commercial environment

Achieving quality is a perennial problem in software development. It is commercially significant because of the large sums of money spent correcting problems within information systems. The literature shows how various theoretical treatments have developed since the late 1970s. However, many of these models are of academic interest only, because they are not perceived by IT professionals to meet their needs.This article describes a study which examined the nature of quality in six different commercial environments. The aim of the study was to provide models of quality appropriate to individual commercial environments and to examine similarities between them. The results, expressed in terms of quality criteria and the relationships between them, highlight the limitations of many theoretical treatments, in particular, the highly technical view of software quality enshrined in early models, and the need for criteria contributing to business correctness.The results from the study are used to highlight some of the important issues in software quality within commercial environments and some of the reasons why quality is often poor.     

Native-XML数据库综述

Native—XML作为一个重要的技术,为面向对象的数据库的存储和处理提供了有力支持。在介绍Native—XML数据库的概念、分类的基础上,分析讨论了现有Native—XML数据库的特点,指出了Native—XML数据库的应用中的问题,并简单介绍了3个典型的Native—XML数据库。     

基于机群架构的并行数据库实现技术研究

在总结了现有并行数据库实现模型的基础上,基于"半重写变换"模型[1]实现了一个并行数据库系统的原型.通过对数据划分/重划分、并行选择、并行排序、并行连接等关键操作的实验分析,指出了.半重写变换"模型存在的缺陷,并提出了一种混合式的改进模型.从理论上说,在机群架构下实现并行数据库系统,这种混合模型较单一模型更有优势.     

基于VB6.0和Access数据库的物性数据查询软件

化工计算中经常用到大量的物性数据,这些数据一般通过手工查询物性手册的方法得到,具有费时耗力的缺点。为解决这一问题,本文利用VB6.0和Access数据库开发了可准确查询1692种物质的物性参数的软件。可查询的物性参数包括常规性质,如英文名、CAS号、结构简式、分子量、熔点和沸点等,以及多种随温度变化的数据,如饱和蒸气压、液体热容、理想气体热容、液体粘度、气体粘度、液体导热系数、气体导热系数、汽化焓、液体密度、表面张力和第二维里系数等。经与《石油化工基础数据手册》对比,证明软件所提供的数据准确可靠。本文详细介绍了随温度变化的数据的温度关联式、软件设计结构和软件窗体界面等。本软件界面友好,使用方便,可移植性强。通过http://iask.sina.com.cn/u/1204072750/ish提供下载交流。     

实现关系型数据与文档型数据间的转换

随着企业IT技术的广泛应用,在企业信息管理中出现了关系型数据和文档型数据等多种数据类型,不同类型之间的数据转挟和数据共享成为企业IT应用的关键。针对此问题,提出了基于Microsoft的开放数据库连接（ODBC）技术、使用Lotus脚本语言实现关系型数据与文档型数据间的相互转换的基本思路和具体解决方法。     

组态软件实时数据库研究

介绍了组态软件及其核心部件实时数据库,通过设计一个工业实时数据库实例,来探讨一些实时数据库的关键问题并提出相应的实现方法和技术措施。     

软件自适应性探讨及其在数据库系统中的应用

对如何提高软件系统的可维护性和自适应性进行了探讨,并用实例介绍了如何在数据库系统中提高系统自适应性的方法。     

Process quality costing adapted to software development

The Prevention-Appraisal-Failure and Process models of measuring quality costs, as described in BS6413, are discussed in the context of software quality costs. The Process model is selected as the better base for constructing a software quality cost model because of its suitability for application to software engineering processes. A seven-step method for modelling software quality costs is proposed and illustrated by application to a software maintenance project. Key processes in software maintenance and its quality tasks are derived from the most recently available standards-related publications. Although no results are available, a qualitative evaluation in terms of accuracy, improvement issues, measurement issues and quality costs to management concludes that the model is valid and that a greater consensus is required for identification of software quality cost elements. Implementation of quality cost measurement is not discussed save noting that there are still complex issues to be addressed.     

The impact of software evolution and reuse on software quality

This paper presents a case study of a software project in the maintenance phase. The case study was based on a sample of modules, representing about 1.3 million lines of code, from a very large telecommunications system. Software quality models were developed to predict the number of faults expected from the coding through operations phases. Since modules from the prior release were often reused to develop a new release, one model incorporated reuse data as additional independent variables. We compare this model's performance to a similar model without reuse data.Software quality models often have product metrics as the only input data for predicting quality. There is an implicit assumption that all the modules have had a similar development history, so that product attributes are the primary drivers of different quality levels. Reuse of software as components and software evolution do not fit this assumption very well, and consequently, traditional models for such environments may not have adequate accuracy. Focusing on the software maintenance phase, this study demonstrated that reuse data can significantly improve the predictive accuracy of software quality models.     

Evaluating the quality of entity relationship models

Entity Relationship (E-R) models are at the core of logical database design. This paper describes the development of a model, associated metrics and methodology for assessing the quality of an E-R model. The model was developed by investigating into the causal relationships between ontological and behavioural factors influencing data quality. The methodology describes aggregation of the scores on various metrics to calculate an overall quality score for an E-R model, and use of the model to identify problem areas if the individual quality scores on different factors do not meet organizational standards. Further possible improvement of the model and future research issues are also discussed.     

InterViso: Dealing with the complexity of federated database access

Connectivity products are finally available to provide the highways between computers containing data. IBM has provided strong validation of the concept with their Information Warehouse. DBMS vendors are providing gateways into their products, and SQL is being retrofitted on many older DBMSs to make it easier to access data from standard 4GL products and application development systems. The next step needed for data integration is to provide (1) a common data dictionary with a conceptual schema across the data to mask the many differences that occur when databases are developed independently and (2) a server that can access and integrate the databases using information from the data dictionary. In this article, we discuss InterViso, one of the first commercial federated database products. InterViso is based on Mermaid, which was developed at SDC and Unisys (Templeton et al., 1987b). It provides a value added layer above connectivity products to handle views across databases, schema translation, and transaction management.     

Reported effects of rapid prototyping on industrial software quality

Empirical data are required to determine the effect of rapid prototyping on software quality. We examine 34 published and unpublished case studies of the use of rapid prototyping in real-world software development. We identify common observations, unique events, and opinions. We develop guidelines to help software developers use rapid prototyping to maximize product quality and avoid common pitfalls.A protion of the results in this paper were reported in a previous paper entitled Rapid Prototyping and Software Quality: Lessons From Industry, that was presented at the 1991Pacific Northwest Software Quality Conference, Portland, Oregon, 1991.     

异构数据库数据类型转换模型

近年来,异构数据的转换和集成是企业应用集成（EAI）一个重要部分.对异构数据库之间的数据转换和共享也成为其主要研究方向之一.在参考了其他数据转换模型的基础上,提出了基于XML文件的数据转换模型DCMHD（Data Conversion Model of HeterogeneousDatabase）.通过模型自定义数据类型,数据库和数据库之间的数据转换可以简化为数据库与系统之间的数据转换,显著提高了系统的稳定性和可扩展性;并且采用XML作为传输介质,易于异构数据的传输和共享,最后给出了模型的主要实现.     

Kingview6.5的数据库功能开发与应用

组态王是国内较优秀的工业自动化通用软件包。本文介绍了KINGVIEW6．5的数据库管理功能，较详细地论述了具体开发过程与应用方法。该功能既增强了系统对数据的访问能力和后续处理能力，又提高了数据的可移植性。实例证明该方法效果良好。     

Software quality assurance in Australia: an update

Three recent events are likely to have a significant impact on the future direction of software quality in Australia: the Kean Report, the redevelopment of Australian standard AS3563 and a review of Government purchasing policy as a result of a change of Commonwealth Government. These events, and their subsequent impacts, could have implications and could provide lessons for the software quality assurance industry internationally. These lessons concern: providing adequate education for purchasers, suppliers and auditors on what ISO9000 is all about; implementing appropriate ISO9000-compliant quality management systems, particularly for small and medium sized enterprises; defining an appropriate role for government; and utilizing effective guidance for adopting ISO9001 to software development.     

Data quality in information systems

Until recently, data quality was poorly understood and seldom achieved, yet it is essential to the effective use of information systems. This paper discusses the nature and importance of data quality. The role of data quality is placed in the life cycle framework. Many new concepts, tools and techniques from both programming languages and database management systems are presented and related to data quality. In particular, the concept of a database constraint is considered in detail. Some current limitations and research directions are proposed.     

基于关系数据库的半结构化XML数据组织技术

XM L数据的组织和管理存在多种方法。描述XM L数据、模式以及半结构化XM L数据特点,介绍XM L数据库与XM L数据存储方法,讨论XM L数据在关系数据库中的组织策略;基于编码机制,将半结构化XM L 编码分成次序编码、路径编码、混合编码和支持更新的扩展编码,分析总结半结构化XM L数据编码技术,展望XM L数据组织技术的发展趋势,为进一步进行XM L数据组织技术研究提供基础。     

Perceptions of software quality: a pilot study

Many software quality initiatives fail because they do not take account of the range of views that people have of quality. New approaches to software quality improvement will not work unless software developers believe in them, no matter how enthusiastic managers may be. This paper reports on a pilot study using the repertory grid technique that found evidence to support these assertions. The study findings justify further work and show that while the repertory grid technique is an appropriate instrument in this area it is resource intensive to apply and may not be practical in a wider study of a representative sample of the IT industry. The paper has practical recommendations for successful introduction of new software quality programmes. These recommendations stress the need for effective communication, leading to a shared understanding of quality, and for realistic goals that recognize the pressure of development schedules.     

组态软件内存实时数据库性能测试

介绍了内存实时数据库在工业控制DCS组态软件中的应用及其在数据采集过程中的重要性;针对组态软件内存实时数据库的特点,测试了在不同的数据组织形式、内存置换页面大小以及缓存大小下数据库的性能,通过测试,得出了不同的配置组合对内存实时数据库性能的影响,从而为下一步的研究工作打下了基础。