Component-based Software Trustworthiness Measurement And Allocation Model

With the rapid development of information technology,the application of computer software is becoming more and more extensive,especially in the aerospace,industrial production,transportation,communications,finance and other important areas related to the national economy and people's livelihood.Once the software breaks down,great losses will be caused,so people's requirements for software quality are getting higher and higher.Software trustworthiness is an important criterion to evaluate software quality.How to measure software trustworthiness has become an important research focus in the field of software engineering,and how to ensure the software trustworthiness in the stage of requirement analysis and development and design is also important too.In order to improve the efficiency and quality of software development and save development costs,more and more software designers adopt component-based development methods,and the trustworthiness of components has a great impact on the quality of software systems.From component point of view,software trustworthiness measurement and trustworthiness allocation are studied,and then software trustworthiness measurement models and software trustworthiness allocation models are constructed.The proposed models try to provide theoretical guarantee for evaluating software quality in software requirement analysis and development design stage.The following are the main research contents:(1)Based on the different combinations of components,system trustworthiness measurement model is established.Firstly,by using components' attributes and weights of each attribute,a component trustworthiness measurement model is established.Secondly,through the division of software architecture,the complex software system is divided into several subsystems,and the subsystems are divided into several components.According to the different combinations of components and the weight of components,subsystem trustworthiness measurement models in different combinations of components are established.Then,these models are proved to satisfy the five metric criteria: non-negativity,monotonicity,adhesiveness,sensitivity and substitutivity.Finally,according to the subsystem trustworthiness measurement model,the software system trustworthiness measurement model is constructed.(2)By using the analytic hierarchy process(AHP),the weight allocation model of components is established.Firstly,two comparison judgment matrices of critical components and non-critical components are constructed respectively to judge the compatibility of the matrix.According to the eigenvalues and eigenvectors of the matrix,the weights of components are allocated.Secondly,the solution of software system trustworthiness measurement models is constructed by using the weight of components.Finally,the weight allocation method and trustworthiness measurement model of components are applied to the case of train ticket purchase system.(3)Based on the principle of minimum cost,a software trustworthiness allocation model is established.Firstly,a software system trustworthiness allocation model is constructed based on the relationship between software trustworthiness and cost.Secondly,according to the different combinations of components,the trustworthiness-cost allocation models of subsystems are established.Thirdly,the genetic algorithm is used to solve the objective function,and the trustworthiness indexes of each subsystem and each component in the software system are obtained.Finally,the allocation model is applied to the case of train ticket purchase system.