Automated fault tree analysis

Although intrinsically contained, the complexity could lead to operator error and automation of the valve sequencing could be beneficial. Jefferis and Schlager applied a quantitative risk assessment technique based on a fault tree analysis to a similar bioreactor sampling valve assembly. Their analysis illustrated the benefits of automation. 

Dehlinger, J., Lutz, R. PLFaultCAT A Product-Line Software Fault Tree Analysis Tool. Automated Software Engineering 13(1), 169-193 (2006)... 

Modeling technique for fault tree analysis automation. 

Based on this language model-based FTA, automation has been developed. OSATE tool may be used to generate fault tree. The generation tool is designed to be flexible and can be re-targeted to more than one fault tree analysis tool. The portion of the tool that extracts the system instance error model can be reused to generate different types of safety artifacts, such as Markov Chains. 

ISA Standard, Safety Instrumented Functions (SIF)— Safety Integrity Level (SIL) Evaluation Techniques Part 3 Determining the SIL of a SIF via Fault Tree Analysis, TR84.00.02-2002, Part 3, 2002. ISA-The Instrumentation, Systems, and Automation Society. Research Triangle Park, NC. 

State machines are also used in the AADL error model annex [20] to describe the failure behavior of components, but in contrast to RCM, these are compiled into generalized stochastic petri nets (GSPNs) for evaluation. Hierarchical abstraction of the failure behavior is applied by summarizing states of the subordinated hierarchy level and building the state machine of the current component in this way. But there is no further guidance or automation regarding abstraction. To the best of our knowledge, we can say that there is no other approach that systemizes hierarchical abstraction of fault tree analysis similar to SCM. 

In this figure, the seleeted initial event can be selected from the design environment, or ean be extracted by applying automated HAZOP, which highlight list of top events that may eause hazard. In this case, product flow rate (F ) is low has been selected as the initial event. The result of the fault tree analysis as generated by CARA shows total of six cut sets up to order four. The results of the fault tree are fed back to HE Results database as associated with each plant physical object. The relationships among proeess variable, fault, component, and failure are used in the automation of generating the fault tree results. The minimum eut sets represents the different seenarios for the occurrence of the top event (output product flow rate is low). 

Within process industries characterized by large production units and high levels of automation, risk and accident analysis is focused on the avoidance of low-probability events entailing serious consequences for the plant and its environment. Safety analysis is based here on causal or probabilistic models of the accidental chain of events that can serve to identify deficiencies in the design of the plant and its protective system as well as to predict the level of risk involved in an operation. Methods developed are fault tree analysis, MORT (Johnson 1975) and INRS (Leplat Rasmussen 1984). A detailed analysis of the actual, individual incident or failure is performed to identify these possible weak spots in the plant and its operation. It is a common experience that human acts play an important role in such industrial mishaps so, especially after the reactor incident at Three Miles Island in 1979, much effort has been spent on developing suitable predictive tools for the... 

Now, efforts have been made to develop suitable software for various methods of plant (process) hazard analysis (PHA). There are a number of papers available where through suitable software it is possible not only to automate one PHA method but to integrate several automated PHA methods such as event tree/fault tree (Chapter V) with HAZOP or HAZOP with FMEA, which will be discussed in the next clause in this chapter. 

For large and complex systems, fault trees tend to grow very large and it is difficult to inspect and interpret them meaningfully. In the final step, a body of fault propagation logic is removed from the analysis by an automated algorithm, which translates the network of interconnected fault trees into a simple table of direct relationships between component and system failures with the help of MATLAB Simulink (Fig. IV/2.6.3-2). It is possible to synthesize more than one interconnected... 

Other approaches deal with the problem of automatically removing existing loops in fault trees. In (Ciarambino, di Torino, Contini, Demichela, Piccinini 2002), syntax rules are used to identify and remove loops. In (Domis Trapp 2008) Boolean structures are analyzed and loops are removed from the safety analysis model. However, these type of approaches require prior recognition by the analyst of the initiation of a loop. To enable automations for fault tree structures that do not require interactions... 

Studies (HiP-HOPS) [12] and Component Fault Trees (CFT) [6]. For specific component-based specification languages, the later two techniques allow tool-supported and automated generation of a safety evaluation model. A limitation of these safety analysis techniques is their inability to handle cycles in the control-or data-flow architecture of the system cycles, of course, appear in most realistic systems. Fault Propagation and Transformation Calculus (FPTC) [15] was one of the first approaches that could automatically carry out failure analysis on systems with cycles by using fixed-point analysis. 

SAM should automate some aspects of safety analysis, e.g. fault tree analyses or reliability calculations, to demonstrate that it can also support classical safety analysis techniques ... 

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