Fault model


Fault model

A fault model is an engineering model of something that could go wrong in the construction or operation of a piece of equipment. From the model, the designer or user can then predict the consequences of this particular fault. Fault models can be used in almost all branches of engineering.

Basic fault models in digital circuits include:
* the stuck-at fault model. A signal, or gate output, is stuck at a 0 or 1 value, independent of the inputs to the circuit.
* the bridging fault model. Two signals are connected together when they should not be. Depending on the logic circuitry employed, this may result in a "wired-OR" or "wired-AND" logic function. Since there are "O(n^2)" potential bridging faults, they are normally restricted to signals that are physically adjacent in the design.
* The open fault model. Here a wire is assumed broken, and one or more inputs are disconnected from the output that should drive them. As with bridging faults, the resulting behavior depends on the circuit implementation.
* The delay fault model, where the signal eventually assumes the correct value, but more slowly (or rarely, more quickly) than normal.

A fault model in an Aerospace context is a set of structured information which helps users or systems to identify and isolate a problem that occurs on an engine, Line-replaceable unit (LRU), or Auxiliary power unit (APU) during a flight. Associated with this fault model may be a suggested repair procedure along with references to Aircraft maintenance manuals (~ Light maintenance manual ).

See also

*Automatic test pattern generation
*Single Stuck Line
*Fault coverage


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Fault tree analysis — (FTA) is a failure analysis in which an undesired state of a system is analyzed using boolean logic to combine a series of lower level events. This analysis method is mainly used in the field of safety engineering to quantitatively determine the… …   Wikipedia

  • Fault-tolerant computer systems — are systems designed around the concepts of fault tolerance. In essence, they have to be able to keep working to a level of satisfaction in the presence of faults. Types of fault tolerance Most fault tolerant computer systems are designed to be… …   Wikipedia

  • Fault coverage — refers to the percentage of some type of fault that can be detected during the test of an electronic system, usually an integrated circuit. High fault coverage is particularly valuable during manufacturing test, and techniques such as Design For… …   Wikipedia

  • Fault friction — describes the relation of friction to fault mechanics. Rock failure and associated earthquakes are very much a fractal operation (see Characteristic earthquakes). The process remains scale invariant down to the smallest crystal. Thus, the… …   Wikipedia

  • Model-based design — (MBD) is a mathematical and visual method of addressing problems associated with designing complex control,[1][2] signal processing[3] and communication systems. It is used in many motion control, industrial equipment, aerospace, and automotive… …   Wikipedia

  • Fault-tolerant system — This article contains specific implementations of fault tolerant systems. For general theory, see fault tolerant design. Fault tolerance or graceful degradation is the property that enables a system (often computer based) to continue operating… …   Wikipedia

  • Model based design — The dawn of the electrical age brought with it various novel, innovative and advanced control systems. It was as early as 1920 s when the two strands of technology, control theory and control system, came together to produce large scale… …   Wikipedia

  • Model-based testing tools — This page lists tools for model based testing in alphabetic order. * [http://www.all4tec.net/index.php?option=com content task=blogcategory id=5 Itemid=75 lang=en All4Tec MaTeLo] is a model based testing tool and an automatic test generator. *… …   Wikipedia

  • Model-based reasoning — In artificial intelligence, model based reasoning refers to an inference method used in expert systems based on a model of the physical world. With this approach, the main focus of application development is developing the model. Then at run time …   Wikipedia

  • Model of masculinity under fascist Italy — The model of masculinity under fascist Italy is the hegemonic masculinity prescribed by dictator Benito Mussolini during his fascist reign. This hegemonic model was deemed as the appropriate, ideal identity to follow during the development of a… …   Wikipedia