Redundancy as an important source of resilience in the Safety II concept

This paper attempts to describe redundancy as an important source of resilient properties within the Safety-II concept. The document first describes the resilience itself and mentions both the genesis of the term and several definitions across disciplines. Last but not least, it provides an appropriate definition of general resilience. The first part also describes the basic attributes of resilience and the principles, that can be used to secure these attributes. The next section describes the fault hypothesis. This section discusses the act possibility of system faults and their consideration in safety design. This section also describes the 3-dimensional failure model, which allows simplification of fault analysis. The following sections describe Safety-I and Safety-II concepts. The context of these two concepts is described here. Chapter 6 describes the use options of resilient properties within the Safety-II concept. The last chapter tries to describe the possibilities of classification of resilience using redundancy. Firstly, the importance of redundancy for resilience and then the use of a 3-dimensional model for redundancy classification are explained. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.