Research On Applications Of Formal Method In Component-Based Software Reuse

Software reuse is a technique that software resources created in preceding software activities can be re-organized and employed in current system development. The resources include not only programs but also the methods, requirement specification, design construction, development tools and environment, testing and analysis data and maintain information, etc. The reusable resources are called component, component is the foundation of software reuse.Formal method is a kind of software development method that is based on strict mathematic foundations. It may be called the formal method that uses the strict mathematical instrument, and has the precise mathematics semantics. The mathematic foundations include symbolic logic, algebra, automata theory, graph theory, etc. Although it has passed several dozens years to research the formal method, But the formal method does not have a precisely and unified definition until now. It aims to enable the software system to have the high accuracy, to enable the system to have the good structure, to be easy to maintain and satisfy the user.The article attempts to apply the formal method to the process of component based software reuse, the goal is to make the process of component reuse more correct, more reasonable, and faster. The main research includes:1. Extract the component relations, and descript the relations by the component relations space. Take the classical proposition logic as the foundation, found the component relations language (Lc), establish the deducing system of component relations, and introduce the use of the deducing system.2. According to the difference of operation time and operator, found a kind of component model (RSAE component model) that can unfold the component information from different aspects.3. In the retrieval part of the RSAE component model, I designed a kind of facet based description method, designed the facet description tree, defined a component match algorithm and the reuse degree of component, etc.4. In the assembly and evolvement part of the RSAE component model, I introduced the B language rationale, and gave an example to demonstrate how to describe the function of component and the criterion of component behavior.