Assessing multi-version systems through fault injection

Multi-version design (MVD) has been proposed as a method for increasing the dependability, of critical systems beyond current levels. However, a major obstacle to large-scale commercial usage of this approach is the lack of quantitative characterizations available. We seek to help answer this problem using fault injection. This approach has the potential for yielding highly useful metrics with regard to MVD systems, as well as giving developers a greater insight into the behaviour of each channel within the system. In this research, we develop an automatic fault injection system for multi-version systems called FITMVS. We use this si,stem to test a multi-version system, and then analyze the results produced. We conclude that this approach can yield useful metrics, including metrics related to channel sensitivity, code scope sensitivity, and the likelihood of common-mode failure occurring within a system.