Metrics Research Based On Requirements Analysis Model And Design Model Of UML

The quality of software is the focus of software engineering. As an important branch of software engineering, the aim of software metrics is to control and assure software quality and improve the efficiency of software development by making using of some useful information receiving from metrics.UML is one kind of modeling language that supports the main concept that aims at object-oriented technique and provides a batch of basic graphs and methods expressing models element, and it can also be well used to object-oriented requirement analysis model and design model. It is very meaningful to make metric research to UML.In this dissertation, the requirement analysis model and design model expressed by UML are studied. The suite of metrics about requirement analysis mode includes:Number of Usecases, Number of Abstract Usecases, Number of Actors, Number of Relative Actor of the Usecases, Number of Relative Actor of the Usecases, Scale of Usecase, Scale of Usecase of System, Complexity of Usecase, Complexity of System, Number of messages of Usecase, Number of Messages of System, Active Complexity of Class. The suite of metrics about design model includes:Number of Children, Depth of the Inheritance Tree, Improved Depth of the Inheritance Tree, Weighted Method Count, Percent of Public Attribute, Lack of Cohesion in Methods, Depending Degree and Depened Degree of Class, Coupling between Object Classes, Message Size of the Usecase Designed, Message Size of System Designed. Throught the study to the subject we can propose some new opinions and have some reasonable improvements to some metrics.Finally based on this theory, a prototype of a metric tool has been developed, and then some experiments and data analyses have been completed. The analyses results indicated:through carrying on the measurement to the model of UML, on the one hand we may better understand the scale of system, complexity of system, function divisions and so on, thus we can assign the manpower and the physical resources well, and we can also have reasonable distribution of our duty. On the other hand it may reflect the accuracy and the rationality of the UML model. It has a quick solution to the problems that appear in the development of the system, and can optimize the development of the software.