Fault Tree Data Structure Based on XML and the Conversion Method to BDD

In this paper we propose an XML based approach called XFTOM (Extensible Fault Tree Object Model) to describe the data structure of Fault Tree. The model can directly describe the data structure, and has the excellent trait to share data through network, and can satisfy the requirement of the computer aided Fault Tree analysis in the environment of the internet/intranet in the future. The traditional fault tree representation encodes a failure logic function which does not lend itself to the mathematical manipulation, a more convenient form for the logic function from the mathematical viewpoint is the Binary Decision Diagram (BDD), the paper also introduces a direct solution Based on XML regularity for building Binary Decision Diagrams(BDD) from Fault trees. Sequence reading and handling a criterion Fault tree in an XFTOM form is introduced here; a well-structured and well-formatted BDD XML document corresponding to the Fault Tree can be obtained smoothly.

1. Introduction

Fault tree is a common tool in reliability and safety analysis. Basic events are connected through a series of logic gates to a top event that usually represents the failure of the system. The perfect data model of Fault tree is important for algorithm implementation and data share. Traditional Fault trees are stored in database table with the structure changed ^[1], and are very difficult to understand or exchange, which hinders its running and sharing through Internet.