DIFtree: A software package for the analysis of dynamic fault tree models

Several recent advances in fault tree models have been developed as an aid in the analysis of computer systems, and these have appeared in the RAMS symposium in the past several years. Such advances include the ability to model sequence dependencies [8, 6], the application of fault trees to the analysis of hardwareand softwarefault tolerant systems [11], the ability to include details of the recovery process in the fault tree solution [2], and the use of modularization [16] and Binary Decision Diagrams as an aid in solution [4]. In this paper we present a software package (DIFtree) that implements these advances into a single methodology that can solve both dynamic and static fault trees, and which is applicable to the analysis of hardware, software and humanware in complex computer-based systems.