Reliability Evaluation Approach For Component-based Software Based On The Complex Network Theory

Component-based software development is the further development of object-oriented technology.Software developers complete the development of the system by using the existing components directly,which achieves the purpose of software reuse.At present,component-based software has become a mainstream software modality,which is widely used in various critical systems.In the component-based software system,the impact of the failure of different components in the system is different because of their different functions and positions in the software.Therefore,to get more accurate and practical assessment results,the importance of each component should be considered in the reliability evaluation process of component-based software system.At the same time,the architecture of component-based software system is also becoming more and more complex.As a result,finding the solution to establish a reliability evaluation model based on software architecture analysis for component-based software system is also one of the most urgent problems to be solved at the moment.To solve the above problems,the component-based software system is taken as the study object in this paper,on the basis of the complex network theory,the importance measure of the internal component nodes and the overall reliability evaluation method of the component-based software system is well studied.First of all,in view of the research on complex network characters of component-based software systems,a new method of measuring the importance of component nodes based on complex network theory is proposed,which abstract the component-based software system as a complex network model and analyze the connection and collaboration between components from a holistic perspective.According to the node importance assessment method in the complex network theory and the types of component nodes in component-based software system,the components of a software system are identified and divided into two categories,input/output components and ordinary components and the importance of each component is assessed by computing its influence factor.Then,on the basis of the state-based reliability evaluation method,a component-based software system reliability evaluation model based on the influence factors of components is presented,taking the components' importance into consideration to get more practical reliability evaluation results.Meanwhile,the influence factor can also be used to find the most important components and provide relative priorities of the components to guide the system reliability optimization.At last,in view of the different software architecture styles in component-based software system(such as sequence-branch structure,parallel structure,fault-tolerance architecture,and call-return structure),an alternative approach for reliability evaluation of component-based software systems based on the complex network theory and structure analysis is presented by analyzing the state transition process of each architecture style.As a result,the calculation method of component's influence factors in different software architecture styles and the reliability evaluation model of the whole system are optimized and the result of reliability evaluation of component-based software system is more scientific,accurate and practical.