Research On Component Applicability Evaluation Model Requirement-oriented

The software reusability is critical to the prosperity of software industry, and becomes the vital means that raises the software productivity. At present, component-oriented software development has laid the foundation for the low cost of software reuse. The process of software development implies both management and technique, the good combination of these two accelerates the development of component-oriented software. With the accretion of the reused component's granularity and the increase of the reused components' quantity, the components selection has become a bottleneck problem of the component-oriented software development.The basis of the component selection is stakeholders' requirement of the software system. In order to raise the effect and efficiency of the component selection, after analyzing the advantages and disadvantages of current component evaluation models, according to the system theories, the syngergetics and the ontology, taking OWL as description language of requirements and components, consulting the requirement management techniques and several component standards, a requirements-oriented component applicability evaluation model is presented. Because the stakeholder describes the system requirements and component with natural language, for raising the accuracy of semantic information being extracted from natural language, the first step in the model is to use OWL to make requirement description structured, which make it easy to identify concept component from the requirement. Taking the concept component as basis to search the component database, using statistics method, relying on tagged corpus to carry on the grammatical analysis to the description of the component function, on the basis of this analysis, calculating semantic matching degree of sentence with thesaurus, thus the matching degree of functional attributes of components is computed; Through semantic matching of the names of interfaces and the parameters of interfaces, using Hungary arithmetic to calculate the matching degree of the parameters, and the matching degree of the interfaces is computed; As for the boolean attribute, matching degree is assigned with 0 or 1; for set attribute, matching degree is calculated according to inclusion relation; matching degree between concept component and component is computed with Analytical Hierarchy Process. Components whose matching degree are more than threshold is put into the selection domains of concept components, and then global optimization of component selection will be achieved by using Dynamic Programming .In the end, the model is implemented and tested. The result shows that the model is of maneuverability, and that the model can fulfil the preconcerted function in certain degree. Meanwhile, advantages and disadvantages of the model have been concluded and the prospect to the model is presented.