面向对象软件度量学的研究

软件度量学是软件工程领域的一个重要研究方向。通过软件度量,可以降低软件开发的成本,提高软件开发的效率,保证软件能满足用户的需求,开发出高质量的软件。本文分析了面向对象软件度量的特点,在著名的C＆K度量方法及其它度量方法的基础上,着重阐述了针对各种不同层次的面向对象的软件度量,包括面向OO项目的度量、面向OO系统的度量、面向类继承树的度量、面向类层的度量、面向方法（操作）的度量。     

基于UML模型的全功能点自动化度量

软件规模在项目估算和决策中起着举足轻重的作用。基于软件需求从用户角度和功能角度度量规模的全功能点(FFP)广受欢迎，但为手工操作，弊端显而易见，所以亟需自动化度量。本文提出并实现了基于UML模型全功能点自动化度量系统，不但能得到精确的量化结果，而且能减轻工作量、降低花费，以及很大程度上避免抽取数据及度量过程中差错所造成的风险，更重要的是具有可重复性，从而易于功能规模度量方法的推广。     

面向对象软件度量技术

提出了OO度量评价规则和标识一组OO度量套件的方法，一组切实可行的OO度量套件及其形式化描述方法，评价OO关键概念和结构特性。质量度量模型是软件质量评价体系中的关键技术，采用层次结构的度量模型。通过质量度量模型，就建立了软件内部属性和外部属性间的客观的定量的联系。OO软件度量框架用以规范化地帮助评测软件产品质量的过程。     

基于UML技术的功能点度量研究与应用

准确的规模度量在做好软件成本估算的过程中有着举足轻重的作用,功能点规模度量分析在业界被应用广泛,但考虑到功能点被分解时随意性较大,而UML是面向对象程序设计方法中进行分析和设计的标准建模语言,于是文章提供了一种使用UML技术中的用例图及用例描述和类图相结合的方法对应用系统进行功能点分析,使得开发者能使用该方法能在开发的早期估算出系统的规模,并将此方法应用于企业信息化协同办公自动化系统中。     

军用型号项目软件复用成本度量模型

针对军用型号项目软件研制过程中普遍存在的软件复用行为,提出了一种复用成本度量方法,对传统的COCOMO2.0成本度量模型进行了改进,采用改进的功能点法估计软件实际规模,适当调整模型中的评估项,增加了度量系统复用的成本驱动因子及系统通用特性统计项（GSC）,建立了相应的量化评估及DI分级表,形成了军用型号项目软件进度、成本估计模型,使用改进的度量模型对某军用型号项目进行了成本度量,验证了方法的有效性。     

基于模糊层次分析法的软件易用性过程综合评价方法

对软件易用性过程进行综合评价是开发可信软件产品的必要因素。通过构建软件易用性生命周期模型和软件易用性度量模型搭建软件易用性过程综合评价模型, 通过此模型对软件开发中的易用性问题进行有效的指导, 规范易用性开发过程, 从而保证能够产出高易用性的产品; 利用模糊层次分析法对此模型进行度量评价, 量化评估易用性过程优劣; 通过一个实例分析说明该方法可以有效地应用于软件开发过程中, 能够尽早地确保软件产品的易用性, 为开发高易用度的软件产品指明了方向。     

基于差异分析的商业构件评估方法

在基于商业构件的软件开发中,构件评估与选择是贯穿整个开发过程的关键步骤。该文提出一种基于差异分析的构件评估方法,通过辨识构件与需求在功能性上的差异,由功能点模型估算以软件功能规模度量的差异及其相应的修正代价。构件对需求的适应度被定义为符合需求的目标系统的功能规模与以功能规模度量的构件总代价的比率。     

应用IFPUG功能点方法的军用软件规模估算

IFPUG功能点方法是国际功能点用户协会提出的一种广泛使用的度量软件功能大小的方法,它不依赖于实现语言,度量出来的结果也可以在不同的开发过程之间进行比较,该文提供了使用该方法对军用软件系统进行规模估算的实施框架,开发者使用该方法在开发的早期能够估算出系统的规模,为后期工作量与成本估算提供可靠依据,在系统完成后可作为系统其他度量和评估的有效输入。     

采用功能点分析法度量软件规模应用研究

对软件规模进行估算和度量已经成为软件规范化开发的基础要求,针对现有软件规模估算中功能点分析法的计算规则及其不足,提出了一种可行的功能点分析法实施准则,并运用线性回归数学模型对开发项目实例的数据进行了演算和分析,评价结果表明线性回归数学模型的可靠性和准确性.     

类规模对面向对象度量易变性预测能力的潜在混和效应:一个元分析

最近的研究表明,类的规模对面向对象(OO)度量的易变性预测能力存在很强的混和效应,因此需要将其作为一个混和变量来考虑,否则有可能会得到误导性的结果.然而,先前的研究仅仅分析了一个软件系统,因此不清楚这个结论是否可以推广到其他系统上.为解决此问题,文中在102个Java软件系统的基础上利用元分析技术检查类的规模对55个OO度量和易变性之间关联关系的潜在混和效应.对每一个OO度量,首先在单个系统上分别计算在控制规模和不控制规模的两种情况下它与易变性的关联强度.然后,利用随机效应元分析模型计算在所有系统上且分别在这两种情况下它与易变性的平均关联强度.最后,在此基础上利用统计方法检测类规模的潜在混和效应.实验结果表明类规模的混和效应是广泛存在的,因此在验证OO度量的易变性预测能力时确实需要将其作为一个混和变量来考虑.     

Towards a simplified definition of Function Points

BackgroundThe measurement of Function Points is based on Base Functional Components. The process of identifying and weighting Base Functional Components is hardly automatable, due to the informality of both the Function Point method and the requirements documents being measured. So, Function Point measurement generally requires a lengthy and costly process.ObjectivesWe investigate whether it is possible to take into account only subsets of Base Functional Components so as to obtain functional size measures that simplify Function Points with the same effort estimation accuracy as the original Function Points measure. Simplifying the definition of Function Points would imply a reduction of measurement costs and may help spread the adoption of this type of measurement practices. Specifically, we empirically investigate the following issues: whether available data provide evidence that simplified software functionality measures can be defined in a way that is consistent with Function Point Analysis; whether simplified functional size measures by themselves can be used without any appreciable loss in software development effort prediction accuracy; whether simplified functional size measures can be used as software development effort predictors in models that also use other software requirements measures.MethodWe analyze the relationships between Function Points and their Base Functional Components. We also analyze the relationships between Base Functional Components and development effort. Finally, we built effort prediction models that contain both the simplified functional measures and additional requirements measures.ResultsSignificant statistical models correlate Function Points with Base Functional Components. Basic Functional Components can be used to build models of effort that are equivalent, in terms of accuracy, to those based on Function Points. Finally, simplified Function Points measures can be used as software development effort predictors in models that also use other requirements measures.ConclusionThe definition and measurement processes of Function Points can be dramatically simplified by taking into account a subset of the Base Functional Components used in the original definition of the measure, thus allowing for substantial savings in measurement effort, without sacrificing the accuracy of software development effort estimates.     

Class point: an approach for the size estimation of object-oriented systems

In this paper, we present an FP-like approach, named class point, which was conceived to estimate the size of object-oriented products. In particular, two measures are proposed, which are theoretically validated showing that they satisfy well-known properties necessary for size measures. An initial, empirical validation is also performed, meant to assess the usefulness and effectiveness of the proposed measures to predict the development effort of object-oriented systems. Moreover, a comparative analysis is carried out, taking into account several other size measures.     

Coupling Trends in Industrial Prototyping Roles: An Empirical Investigation

Prototyping in the development cycle claims to improve analyst understanding of system requirements leading to systems which match those requirements more closely. The quality of the end systems, from a user perspective, is thus improved. In this paper, the results of an empirical investigation into the use of prototyping in the development of various systems is described. Nine processes across eight different sites were analysed and data relating to each process was collected. The notation of Role Activity Diagrams (RADs) was used to capture each of the nine processes. Five hypotheses were then investigated: these related the prototyping role to features of other roles such as extent of interaction during the prototyping process, the effect site size had on the prototyping role and the dependence of the prototyping role on other roles in the prototyping process. Two coupling metrics were introduced to quantitatively analyse these RAD features. Results indicated a strong similarity between large and medium-sized sites in terms of interactions and behaviour. The prototyping process in small sites, however, was found to be different to large and medium-sized sites in both respects. The study demonstrates how measures of business models can aid analysis of the process as well as the products of systems development and highlights the need for more empirical investigation into this and other facets of the software development process.     

Complexity measures for rule-based programs

Software complexity measures are quantitative estimates of the amount of effort required by a programmer to comprehend a piece of code. Many measures have been designed for standard procedural languages, but little work has been done to apply software complexity concepts to nontraditional programming paradigms. This paper presents a collection of software complexity measures that were specifically designed to quantify the conceptual complexity of rule-based programs. These measures are divided into two classes: bulk measures, which estimate complexity by examining aspects of program size, and rule measures, which gauge complexity based on the ways in which program rules interact with data and other rules. A pilot study was conducted to assess the effectiveness of these measures. Several measures were found to correlate well with the study participants' ratings of program difficulty and the time required by them to answer questions that required comprehension of program elements. The physical order of program rules was also shown to affect comprehension. The authors conclude that the development of software complexity measures for particular programming paradigms may lead to better tools for managing program development and predicting maintenance effort in nontraditional programming environments     

Can software risk management improve system development: an exploratory study

Software risk management can be defined as an attempt to formalise risk oriented correlates of development success into a readily applicable set of principles and practices. Earlier research suggests that it can reduce the likelihood of a system failure. Using a survey instrument we investigate this claim further. The investigation addresses the following questions: (1) which characteristics of risk management practices; and (2) which other environmental and process factors (such as development methods, manager's experience) relate to improved performance in managing software risks? Our findings support in general the claim that the use of risk management methods improves system development performance. Yet, little support was found for the claim that specific risk management methods are instrumental in attacking specific software risks. Overall, risks are better managed with combined measures of having experienced project managers, selecting a correct project size, and investing in and obtaining experience in risk management deliberations.     

A vector-based approach to software size measurement and effortestimation

Software size is a fundamental product measure that can be used for assessment, prediction and improvement purposes. However, existing software size measures, such as function points, do not address the underlying problem complexity of software systems adequately. This can result in disproportional measures of software size for different types of systems. We propose a vector size measure (VSM) that incorporates both functionality and problem complexity in a balanced and orthogonal manner. The VSM is used as the input to a vector prediction model (VPM) which can be used to estimate development effort early in the software life-cycle. We theoretically validate the approach against a formal framework. We also empirically validate the approach with a pilot study. The results indicate that the approach provides a mechanism to measure the size of software systems, classify software systems, and estimate development effort early in the software life-cycle to within ±20% across a range of application types     

浅析Web应用软件开发安全

Web应用软件的安全问题日益突出, 提高软件代码自身安全和在软件开过程中控制安全风险成为亟需解决的问题. 本文首先剖析了Web应用常见的安全漏洞, 分析其表现形式、形成原因、规避措施, 并提出了在软件开发生命周期全过程中预防安全漏洞的措施和方法. 通过从软件开发过程管理和技术手段两个方面系统性地预防Web应用安全风险, 有效地提高了交付Web应用软件的安全性.     

Optimal selection of soft sensor inputs for batch distillation columns using principal component analysis

In this paper, a novel methodology based on principal component analysis (PCA) is proposed to select the most suitable secondary process variables to be used as soft sensor inputs. In the proposed approach, a matrix is defined that measures the instantaneous sensitivity of each secondary variable to the primary variables to be estimated. The most sensitive secondary variables are then extracted from this matrix by exploiting the properties of PCA, and they are used as input variables for the development of a regression model suitable for on-line implementation.This method has been evaluated by developing a soft sensor that uses temperature measurements and a process regression model to estimate on-line the product compositions for a simulated batch distillation process. The identification of the optimal soft sensor inputs for this case study has been discussed with respect to the definition of the sensitivity matrix, the data sampling interval, the presence of measurement noise, and the size of the input set. The simulation results demonstrate that the proposed approach can effectively identify the size and configuration of the input set that leads to the optimal estimation performance of the soft sensor.     

Component Point: A system-level size measure for Component-Based Software Systems

System-level size measures are particularly important in software project management as tasks such as planning and estimating the cost and schedule of software development can be performed more accurately when a size estimate of the entire system is available. However, due to the black-box nature of components, the traditional software measures are not adequate for Component-Based Software Systems (CBSS). In this paper, we describe a Function Point-like measure, named Component Point (CP), for measuring the system-level size of a CBSS specified in the Unified Modelling Language. Our approach integrates three software measures and extends an existing size measure from the more matured Object-Oriented paradigm to the related and relatively young CBSS discipline. We then apply the proposed measure to a Global Positioning System and demonstrate its viability in sizing a CBSS. An empirical analysis is also provided in order to prove the validity and usefulness of the CP measure.     

μcROSE: automated measurement of COSMIC-FFP for Rational Rose RealTime

During the last 10 years, many organizations have invested resources and energy in order to be rated at the highest level as possible according to some maturity models for software development. Since measures play an important role in these models, it is essential that CASE tools offer facilities to automatically measure the sizes of various documents produced using them. This paper introduces a tool, called μcROSE, that automatically measures the functional software size, as defined by the COSMIC-FFP method, for Rational Rose RealTime models. μ_cROSE streamlines the measurement process, ensuring repeatability and consistency in measurement while reducing measurement cost. It is the first tool to address automatic measurement of COSMIC-FFP and it can be integrated into the Rational Rose RealTime toolset.