Faults terminology

If a rock is sufficiently stressed, the yield point will eventually be reached. If a brittle failure is initiated a plane of failure will develop which we describe as a fault. Figure 5.6 shows the terminology used to describe normal, reverse and wrench faults. 

The fault tree is constructed based on the system description and initiating events identified in the HAZOP. Figure 5.2 shows a portion of an extended version of Ozog s fault tree, taken from CCPS (1989b). The following terminology is used ... 

To understand the goals of the particular contributions and to compare the different approaches of diagnosis, the IFAC (i.e., International Federation on Automatic Control) Technical Committee SAFEPROCESS (Fault Detection, Supervision and Safety for Technical Processes) has defined a common terminology. These definitions, detailed in [13] will be adopted throughout the present chapter. 

Another important contribution of the referenced terminology was the fault - error - failure -. .. chain, which provides a deeper understanding of fault propagation, fault containment and fault consequences in critical systems A fault in a hardware part, component or subsystem may lead to an erroneous state of this element of the system, which may lead to a failure of this element (the fault is the cause of the error respectively failure, the failure the consequence of the fault respectively error). The failing component constitutes a fault of the subsystem where it is embedded, and so on. This is... 

The terminology and classification of fault-rocks and seal types is not yet universally agreed (Knipe, 1992a Knott, 1993). The classification presented below is based on identification of the main process responsible for the reduction in permeability associated with the faults. Mechanistic terms have been combined with textural descriptive terms to provide a more expansive nomenclature system which covers the most common fault rocks and seat types. The fault seal types and associated fault-rock types can be divided into two broad categories ... 

Laprie J. Dependable computing and fault tolerance concepts and terminology. Laboratory for analysis and architecture of systems. National Center for Scientific Research 1985. http // www.macedo.ufbabr/conceptsANDTermonology.pdf. 

The book is organized as follows Chap. 2 presents the terminology and general concepts used in this work. Chapter 3 describes existing fault tolerant techniques for processors presented in the literature. Chapter 4 describes the fault tolerant techniques implemented in this work to detect transierrt fairlts in processors, from which two are known software-based and three are new lybrid techniques. Chapter 5 presents experimental fault injection campaigns for the implemented fairlt tolerarrt techniques. Chapter 6 presents the configuration bitstream fairlt injection campaign and results. Chapter 7 presents radiation experiments on some of the proposed techniques. Chapter 8 describes future work and concludes the book. 

Due to the ISO/IEC representatives, industrial experts and national bodies there is a set of terminology related to the issue of failure. Failure according to the present version of the lEC 60050 (191) is defined as termination of the ability of an item to perform a required function . There are three things to note (1) After failure the item has a fault (2) Failure is an event, as distinguished from fault, which is a state and (3) This concept as defined does not apply to items consisting of software only. Failure according to the newly upgraded... 

Laprie, J.-C. Dependabifity computing and fault tolerance Concepts and terminology. Fault-Tolerant Computing - Highlights from Twenty-Five Years, 2-13 (June 1995),... 

To understand how maintainability influences the integrity of a safety-critical system, it is first necessary to examine possible responses to equipment failure. Using the lEC terminology that Failure is a deviation from specified service and a Fault is the cause of a failure, the sequence of events arising from a fault... 

LAP 92] Lapre J.C., Avizenis A., Kopetz H. (eds), Dependability basic concepts and terminology , in Dependable Computing and Fault-Tolerant System, vol. 5, Springer, New York, 1992. 

The EUC risk (lEC terminology) is then due to a range of mechanical defects and PLC control/instrument defects. The fault tree shows how these defects are grouped imder certain types of hazards all leading up to the potential for an explosion. The failure rates are estimated values but they do comply with the lEC requirement that normal control systems should not be credited with a failure rate lower than 10 per hr. 

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