Hazards analysis: Failure Mode and

Some of the hazard analysis (evaluation) techniques already used by the chemical industry include traditional system safety tools such as preliminary hazard analysis, failure modes and effects analysis, and fault tree analysis. 

In the aerospace domain, safety considerations, methods, guidelines and certifications are applied for a long time [2] [3], establishing a safety lifecycle. State of the art processes, concerning safety in the automotive domain, base on hazard analysis, failure mode and effect analysis (EMEA) [4], fault tree analysis (ETA) [5], Markov chains and reviews. A standardized safety lifecycle is not yet applied in the automotive domain. 

Functional hazard analysis is the airline industry s name for hazard analysis. Failure mode and effects analysis and fanlt tree analysis are applied in the same way as in other industries. Zonal analysis is the verification of correct manufacture and installation. It starts by reviewing drawings and analysis and ends in the physical inspection of mockup, prototype, and production systems. 

Several qualitative approaches can be used to identify hazardous reaction scenarios, including process hazard analysis, checklists, chemical interaction matrices, and an experience-based review. CCPS (1995a p. 176) describes nine hazard evaluation procedures that can be used to identify hazardous reaction scenarios-checklists, Dow fire and explosion indices, preliminary hazard analysis, what-if analysis, failure modes and effects analysis (FMEA), HAZOP study, fault tree analysis, human error analysis, and quantitative risk analysis. 

A Brief Overview of Selected System Safety Analytical Approaches Working with the Risk Assessment Matrix Preliminary Hazard Analysis Energy Flow/Barrier Analysis Failure Modes and Effects Analysis Fault Tree Analysis... 

Laundry lists of analyses frequently mix types of analyses (preliminary hazard analysis, system hazard analysis, and operating hazard analysis) with the methods or techniques for performing analyses (fault tree analysis, energy trace and barrier analysis, failure modes and effects analysis, common cause analysis, change analysis, and so on). Whether fault hazard analysis is a type or a method depends upon the reference in use. For all practical purposes, fault hazard analysis and system (or subsystem) hazard analysis seem to be the same thing, which is apparently called gross hazard analysis occasionally. 

The hazard identification and evaluation of a complex process by means of a diagram or model that provides a comprehensive, overall view of the process, including its principal elements and the ways in which they are interrelated. There are four principal methods of analysis failure mode and effect, fault tree, THERP, and cost-benefit analysis. Each has a number of variations, and more than one may be combined in a single analysis. See also Cost-Benefit Analysis Failure Mode and Effects Analysis (FMEA/FMECA) Fault Tree Analysis (FTA) THERP (Technique for Human Error Rate Probability). 

In ANSI/ASSE Z590.3—2011, the Prevention through Design standard, Addendum G comments on only eight hazard analysis and risk assessment techniques, intentionally. They are Preliminary Hazard Analysis, What-If Analysis, Checklist Analysis, What-If Checklist Analysis, Hazard and Operability Analysis, Failure Mode and Effects Analysis, Fault Tree Analysis, and Management Oversight and Risk Tree (MORT). It was also said in Z590.3 that ... 

Chapters 5 through 9 describe the different safety analysis tools available. Hazard Analysis, H AZOF, What-If, Fault Tree Analysis, Failure Modes, and Effects Analysis, Human Factors, Software Safety, and other safety tools are described with realistic worked examples. The chapters detail how to use them, give examples, describe common mistakes in using them, and also provide best practices and tips of how to apply them judiciously. 

There are many hazard analysis formulations which may be used effectively to assess process hazards. These include fault-free analysis, failure mode and effect analysis (FMEA), what-if analysis, hazard and operability analysis (HAZOP), check list analysis, and safety review, among others. The specifics associated with these analyses can be reviewed by consulting the appropriate American Institute of Chemical Engineers Center for Chemical Process Safety reference. " ... 

Chapter 3 presents introductory aspects of safety and reliability. Chapter 4 presents a number of methods considered useful for performing safety and reliability analyses in the oil and gas industry. These methods are root cause analysis, hazard and operability analysis, technique of operations review, interface safety analysis, preliminary hazard analysis, job safety analysis, failure modes and effect analysis, fault tree analysis, and the Markov method. 

The system safety case of corrrse varies from sector to sector. The core of a nuclear system safety case is (i) a deterministic analysis of the hazards and farrlts which could arise and cause injury, disability or loss of life fiom the plarrt either on or off the site, and (ii) a demonstration of the sufficiency and adequacy of the provisions (engineering and procedural) for ensuring that the combined frequencies of such events will be acceptably low. Safety systems will feature amongst the risk reducing provisions comprised in this demonstration, which will thus include qualitative substantiations of compliance with appropriate safety engineering standards supplemented (where practicable) by probabihstic analyses of their reliabilities. Other techniques which may be used for stracturing the safety case include fault and event tree analysis, failure mode and effects analysis (FMEA) and hazard and operability studies (HAZOPS). 

There are numerous methods and techniques developed in areas such as safety, reliability, and quality for conducting various types of analysis [23-25]. Some of these methods and techniques can also be used to perform rail safety analysis. These methods and techniques include fault-tree analysis, hazards and operability analysis, cause-and-effect diagram, interface safety analysis, failure modes and effect analysis, and Pareto diagram. One of these approaches (i.e., fault-tree analysis) is presented below, and information on other methods and techniques is available in Chapter 4 and in the literature [23-25]. 

Hazard Analyses have been generated to identify and resolve potentially hazardous conditions, and these analyses are compatible with the associated Failure Modes and Effects Analysis/Failure Modes and Effects Criticality Analysis (FMEA/EMECA) as applicable... 

Methods for performing hazard analysis and risk assessment include safety review, checkhsts, Dow Fire and Explosion Index, what-if analysis, hazard and operabihty analysis (HAZOP), failure modes and effects analysis (FMEA), fault tree analysis, and event tree analysis. Other methods are also available, but those given are used most often. 

Process Hazards Analysis. Analysis of processes for unrecogni2ed or inadequately controUed ha2ards (see Hazard analysis and risk assessment) is required by OSHA (36). The principal methods of analysis, in an approximate ascending order of intensity, are what-if checklist failure modes and effects ha2ard and operabiHty (HAZOP) and fault-tree analysis. Other complementary methods include human error prediction and cost/benefit analysis. The HAZOP method is the most popular as of 1995 because it can be used to identify ha2ards, pinpoint their causes and consequences, and disclose the need for protective systems. Fault-tree analysis is the method to be used if a quantitative evaluation of operational safety is needed to justify the implementation of process improvements. 

The lists of critical items that were described under Identifying controls in Part 2 Chapter 2, together with Failure Modes and Effects Analysis and Hazard Analysis, are techniques that aid the identification of characteristics crucial to the safe and proper functioning of the product. 

All of these factors determine the stress experienced by the workers and the extent to which operational errors will be recovered before disastrous consequences have ensued. In this context, hazard identification techniques, such as hazard and operability studies (HAZOP), failure modes and effects and criticality analysis (FMECA), fault trees, and others are useful in making the process environment more forgiving. 

Failure Modes and Effects Analysis (FMEA) A hazard identification technique in which all known failure modes of components or features of a system are considered in turn and undesired outcomes are noted. 

Hazard Analysis Report - Hazard and Operability Study (HAZOP), failure mode and effect analysis, quantitative fault tree analysis or what/if check list (sec Part IV for details in theses subjects)... 

The what-if analysis is a creative, brainstorming examination of a process or operation conducted by a group of experienced individuals able to ask questions or voice concerns about undesired events. It is not as inherently structured as some other methods, such as the hazard and operability (HAZOP) study or a failure mode and effects analysis (FMEA). 

V Process hazard analysis (PHA) must be performed by a team of experts, including engineers, chemists, operators, industrial hygienists, and other appropriate and experienced specialists. The PHA needs to include a method that fits the complexity of the process, a hazards and operability (HAZOP) study for a complex process, and for less complex processes a less rigorous process, such as what-if scenarios, checklists, failure mode and effects analysis, or fault trees. 

Preliminary hazard analyses (PHAs) have been conducted for the SILVER II process at various stages of design and have served as building blocks for the EDP PHA effort (AEA, 2001a). These PHAs use the Failure Modes and Effects Analysis (FMEA) technique in accordance with the following regulations and standards ... 

Other examples of inductive tools that have limited application in incident investigation include failure mode and effects analysis (FMEA), hazard and operability study (HAZOP), and event tree analysis (ETA). These are detailed in the CCPS book, Guidelines for Hazard Evaluation Procedures... 

The rest of this section outlines the core sub-processes to support safety analyses (compare [F. Redmill, (2004)], [N. G. Leveson, (2004)], [Ch. Blechinger, (2004)], [J. Zalewski and all, (2003)]). The processes place techniques, such as Hazard And Operability Studies (HAZOP), Failure Modes and Effects Analysis (FMEA) and Fault Tree Analysis (FTA), into context. 

The process hazards analysis is conducted by an experienced, multidisciplinary team that examines the process design, plant equipment, operating procedures, and so on, using techniques such as hazard and operability studies (HAZOP), failure mode and effect analysis (FMEA), and others. The process hazards analysis recommends appropriate measures to reduce the risk, including (but not limited to) the safety interlocks to be implemented in the safety interlock system. 

Design Process design checks Unit processes Unit operations Plant equipments Pressure systems Instrument systems Hazard and operability studies (fine scale) Failure modes and effects analysis Fault trees and event trees Hazard analysis Reliability assessments... 

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