An Exploration for Improving Robustness of AUTOSAR Software Components with Design by Contract

Abstract

The increasing volume of software in vehicles makes robustness a significant quality attribute for vehicle software. In order for high quality and high development efficiency of the vehicle embedded software, Automotive Open System Architecture (AUTOSAR) was put forward by several large manufacturers and suppliers in the automotive industry around the world. In this thesis, Design by Contract is applied to improve robustness of existing AUTOSAR software components. The main idea of Design by Contract is to view the relationship between two components as a formal contract which expresses each component’s right and obligations. The specific way is to separate input, output and invariant checks from the main processing component and build additional components for them. Functions for checking pre-conditions, post-conditions and invariants are defined in these components respectively. Each function is invoked every time the corresponding check is needed. The proposed solution is validated by conducting testings for the original and modified components in the unit testing tool ARUnit and comparing the results. The results prove Design by Contract greatly increase the robustness of AUTOSAR software components. None of the testings for the modified software components failed. Certainly, this method has weaknesses such as possible errors brought by the newlybuilt components. And also, it is hard to modify the components of which the code is automatically generated from some model tools.