中等COCOMO模型在中小型软件项目投资决策中的应用探讨

中等COCOMO模型是经过实际软件项目验证和修正的软件成本估算模型.文章将中等COCOMO模型应用于中小型软件项目投资决策,提出了一套简便而完整的中小型软件项目投资分析方法.     

构造性成本模型COCOMO

软件估算已成为众多研究的主题。而构造性成本模型COCOMO无疑是其中最为浓墨重彩的一笔。COCO-MO以其独特的优势成为应用范围最广的软件成本估算模型,也是其他众多软件估算方法或模型研究对比、参考和引用的对象。所以对其进行全面而深入的分析是很有意义的。本文在剖析模型原理的同时,把COCOMO作为软件成本估算模型的优势、存在的问题及未来的发展之路作为本文讨论的重点。     

基于COCOMO模型的软件测试成本估算

本文介绍了软件界影响最为广泛、也最著名的软件开发成本估算模型COCOMO,并且根据软件测试工作成本难以估算的特点,将COCOMO估算模型应用于软件测试成本估算工作中,以提高软件测试成本估算效率和成功率。     

COCOMO II—软件项目管理中的成本估算方法

结构化成本模型(COCOMO：Costructive Cost Model)是一种成熟的软件成本估算方法,将介绍其第二版：COCOMO II模型的基本思路和使用方法,以及对原有COCOMO模型的改进。     

COCOMOⅡ--软件项目管理中的成本估算方法

结构化成本模型（COCOMO：Costructive Cost Model)是一种成熟的软件成本估算方法,将介绍其第二版：COCOMOⅡ模型的基本思路和使用方法,以及对原有COCOMO模型的改进。     

软件开发成本估算模型的研究

软件成本准确地估算和管理控制是软件项目开发成功的基础。该文分析了影响软件开发成本估算准确性的因素,并详细介绍了IBM模型、Putnam模型和COCOMO模型三种经验估算模型,探讨了软件开发成本估算的新需求。     

基于COCOMO模型的软件成本估算工具研究

软件成本估算在软件项目管理中占据重要地位,目前已有多种软件成本估算的模型．其中COCOMO模型最为人们所关注。但对于如何估算该模型中的软件规模这一问题．相关的研究还较少。若能从功能点分析方法入手,计算出软件的功能点数目。再将它根据统计结果转换成相应的软件规模,将会大大提高COCOMO模型使用的准确程度．并进一步提高COCOMO工具的实用性。     

非基于软件复用的成本估算模型的复用改造模型及模型系数修正策略

作为软件成本控制管理的重要措施,软件开发成本的估算技术已经成为软件工程领域的一个重要课题。当前基于复用的软件开发正在成为软件工程的主流,但将软件复用考虑进成本估算的模型较少。提出一个基于软件复用的成本估算模型,并应用该模型对COCOMO模型进行复用改造,之后通过实例进行验证。给出了使用存储过程技术对模型参数进行修正的策略,以为各类基于复用的软件开发成本估算提供依据。     

构建基于软件过程的成本模型

在分析COCOMOⅡ模型的基础上,提出了一个基于软件过程的成本模型,其中的数量模型既可以避免COCOMO模型度量的复杂性,又可以根据实际数据描述非线性的成本与驱动因素之间的映射关系.该模型还描述了在实际软件过程中成本度量方法,以及利用过程成本度量数据实现估算和成本控制的机制.     

项目度量中对基本COCOMO进行校准的研究

所有成功的软件组织都将度量作为保证自己管理和技术质量的重要手段，软件成本估计则是软件度量的核心任务。为了提高成本估算的准确性，文中根据特定软件企业中的历史项目数据对基本COCOMO模型进行校准，在具体的参数修正方法上利用对数数据相关算法进行校正，并与其它方法进行了比较，得到了满意的结果。校准后的模型对项目开发成本的预测将会更加准确，从而切实体现COCOMO成本度量工作对于软件项目的指导价值。因此，文中所做的成本估算模型的校准工作，对软件开发企业非常具有实用价值。     

Cost models for future software life cycle processes: COCOMO 2.0

Current software cost estimation models, such as the 1981 Constructive Cost Model (COCOMO) for software cost estimation and its 1987 Ada COCOMO update, have been experiencing increasing difficulties in estimating the costs of software developed to new life cycle processes and capabilities. These include non-sequential and rapid-development process models; reuse-driven approaches involving commercial off-the-shelf (COTS) packages, re-engineering, applications composition, and applications generation capabilities; object-oriented approaches supported by distributed middleware; and software process maturity initiatives. This paper summarizes research in deriving a baseline COCOMO 2.0 model tailored to these new forms of software development, including rationale for the model decisions. The major new modeling capabilities of COCOMO 2.0 are a tailorable family of software sizing models, involving Object Points, Function Points, and Source Lines of Code; nonlinear models for software reuse and re-engineering; an exponentdriver approach for modeling relative software diseconomies of scale; and several additions, deletions and updates to previous COCOMO effort-multiplier cost drivers. This model is serving as a framework for an extensive current data collection and analysis effort to further refine and calibrate the model's estimation capabilities.     

Improving the COCOMO model using a neuro-fuzzy approach

Accurate software development cost estimation is important for effective project management such as budgeting, project planning and control. So far, no model has proved to be successful at effectively and consistently predicting software development cost. A novel neuro-fuzzy Constructive Cost Model (COCOMO) is proposed for software cost estimation. This model carries some of the desirable features of a neuro-fuzzy approach, such as learning ability and good interpretability, while maintaining the merits of the COCOMO model. Unlike the standard neural network approach, the proposed model can be interpreted and validated by experts, and has good generalization capability. The model deals effectively with imprecise and uncertain input and enhances the reliability of software cost estimates. In addition, it allows input to have continuous rating values and linguistic values, thus avoiding the problem of similar projects having large different estimated costs. A detailed learning algorithm is also presented in this work. The validation using industry project data shows that the model greatly improves estimation accuracy in comparison with the well-known COCOMO model.     

Knowledge-based risk assessment and cost estimation

A knowledge-based method for software project risk assessment and cost estimation has been implemented on multiple platforms. As an extension to the Constructive Cost Model (COCOMO), it aids in project planning by identifying, categorizing, quantifying and prioritizing project risks. It also detects cost estimate input anomalies and provides risk control advice in addition to conventional COCOMO cost and schedule calculation.The method has been developed in conjunction with a system dynamics model of the software development process, and serves as an intelligent front end to the simulation model. It extends previous research in the knowledge-based cost estimation domain by focusing on risk assessment, incorporating substantially more rules, going beyond standard COCOMO, performing quantitative validation, providing a user-friendly interface, and integrating it with a dynamic simulation model.Results of the validation are promising, and the method is being used at Litton Data Systems and other industrial environments. It will be undergoing further enhancement as part of an integrated capability for software engineering to assist in system acquisition, project planning and risk management.     

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。     

项目度量中对基本COCOMO进行校准的研究

所有成功的软件组织都将度量作为保证自己管理和技术质量的重要手段,软件成本估计则是软件度量[1,2]的核心任务。为了提高成本估算的准确性,文中根据特定软件企业中的历史项目数据对基本COCOMO模型进行校准,在具体的参数修正方法上利用对数数据相关算法进行校正,并与其它方法进行了比较,得到了满意的结果。校准后的模型对项目开发成本的预测将会更加准确,从而切实体现COCOMO成本度量工作对于软件项目的指导价值。因此,文中所做的成本估算模型的校准工作,对软件开发企业非常具有实用价值。     

COCOMO as a schedule prognosis and validation tool: a case study

This paper describes a case study in the use of the COCOMO cost estimation model as a tool to provide an independent prognosis and validation of the schedule of a software project at IBM UK Laboratories Ltd, Hursley. Clearly case studies have the danger of being anecdotal however software engineers often work in situations where sufficient historical data is not available to calibrate models to the local environment. It is often necessary for the software engineer to attempt to use such tools on individual projects to justify their further use. This case study describes how we began to use COCOMO and concentrates on some of the problems and benefits which were encountered when trying to use COCOMO in a live development environment.The paper begins by discussing some problems in mapping the COCOMO phases on to the IBM development process. The practical aspects of gathering the development parameters of the model are described and the results of the work are presented in comparison to a schedule assessment using other prognosis techniques and the planned schedule at other milestones in the project's history. Some difficulties experienced in interpreting the data output from the model are discussed. This is followed by a brief comparison with other schedule analysis techniques used in quality assurance. We hope this case study shows that despite the problems in trying to use models such as COCOMO there are significant benefits in helping the user understand what is required to use such tools more effectively to improve software development cost estimates in the future.