A model for CPS software system trustworthiness evaluation based on attributes classifying

Cyber-Physical System is a kind of new systems by combining physical world with computation processes. There are many kinds of software in Cyber-Physical System, and the software system is composed of them. It's difficult for the software system to examine the attributes such as correctness, safety, reliability by using software testing or formal method. So we propose a model for CPS software system trustworthiness evaluation based on trustworthiness attributes. Firstly, present a method to calculate the satisfaction of trustworthiness attributes by considering the aging of trustworthiness evidences; secondly, based on the weight distribution, a software trustworthiness calculating method is brought forward. Then based on the trustworthiness of software and the logical structures of the software system, we present a method to evaluate the trustworthiness level of CPS software system. At Last, we use an example to explain the effectiveness of the model.