Research And Application On Software Cost Model And Optimal Release Question

As the development of computer technology, software systems are increasingly used in all fields of the society, therefore the quality and cost of software are drawing more and more attention. However, the cost and reliability of software are mutual restraining factors: the improvement of the software reliability often leads to increased costs, and the reduced investment will also result in the failure to meet requirements of software reliability. Software optimal release question is used to solve the problem that software cost and reliability are mutually restraining factors. It aims at determining an optimal release time to help decision-makers predict the cost budget and software reliability standards.The existing studies of software optimal release question just focus on how to create more effective and realistic software reliability growth models, but lack of research on software cost models and software optimal release tactics, and then reduces its value. This article focused on software cost and software optimal release tactics,proposed two cost models, the one considering the difference between operating environment and testing environment, while the other one considering fault correction delay. At last, this article proposed a multi-objective optimization method which optimized software cost and reliability at the same time. The main contents are as follows:Firstly, this article analyzed the research status of software cost models and optimal release question, and then discussed the improvement of the existing research, proposing the topics of this article.Secondly, the difference between operating environment and testing environment which is prevalent in software lifecycle was studied. Then, we used the exponential function of environmental factors to discuss the effects of environmental differences on the various stages of software cost. On this basis, we proposed a more realistic cost function, building a software cost model considering the difference between operating environment and testing environment.Then,the difference between the fault detection process and the fault correction process was studied. From the perspective of time, we analyzed and verified the impact of the fault correction delay on software costs at the basis of time delay function. We also took the problem into account that there was a lower fault detection rate in software operating phase,and then built a cost model considering the fault correction delay.Finally, this article studied the question of software optimal release. In order to solve the shortage of the exiting research, we proposed a method that could optimize the cost and reliability at the same time. We used the theory of fuzzy mathematics to build the fuzzy sets of cost and reliability. And then, based on the aggregation operator, we achieved the multi-objective optimization. Combined with the failure data of ECDIS, the cost models that built in this article was applied to the software optimal release question. And then we discussed the optimal release time of ECDIS, verified the value of this article through the actual data.