Enhanced-condition-MC/DC: A method for improving MC/DC testing adequacy

Abstract

The Modified Condition Decision Coverage (MC/DC) test criterion is a mandatory requirement for the testing of avionics software as per the DO-178B standard. In the implementation of safety-critical software, there are many complex logics and testing requirements are relatively high. In structure-based testing, MC/DC coverage has a strong ability to detect errors compared to decision or condition coverage. However, it isn't enough to prove that the implementation is correct; there may be defects still lurking in the software. In this paper we classified the flaws in Boolean expressions into four types based on the software faults model and analyzed the MC/DC sensitivity to these flaws. We found that MC/DC is not sensitive to the relational condition boundary error. Additionally, we present a testing criteria called Enhanced-Condition-MC/DC (EC-MC/DC) as a method of improving MC/DC testing adequacy. The validity and feasibility of the method are verified by real-world open source programs.