Systematic Cause Analysis Technique

Checklist analysis tools can be a user-friendly means to assist investigation teams as they conduct root cause analysis.h) Each causal factor is reviewed against the checklist to determine why that factor existed at the time of the incident. The Systematic Cause Analysis Technique (SCAT)(9> is an example of a proprietary checklist tool. 

International Loss Control Institute. SCAT—Systematic Cause Analysis Technique. Loganville, GA Det Norske Veritas, 1990. 

A variety of public and proprietary checklists are available that vary in comprehensiveness. There is no reason for an organization to start from scratch in developing a checklist. A human factors checklist and tables are included in Chapter 6. The Systematic Cause Analysis Technique (SCAT)< > is an example of a proprietary checklist. The accompanying CD-ROM also contains examples of checklists which can be modified for the readers use. 

Systematic Cause Analysis Technique (SCAT) Information... 

The Causal Factors Chart is a formal, and systematic, incident investigation and root cause analysis technique. The technique depicts the events and conditions leading up to an incident. It combines critical thinking, logical analysis, and graphic representations to analyze and depict an incident event scenario. It helps strncture the analysis and data gathering processes to ensure necessary and snfficient information is collected. The CFC also has been applied to Root Cause Analysis. The CFC is sometimes referred to as the Events and Causal Factors (ECF) chart. The ECF chart depicts the necessary and sufficient events and causal factors associated with a specific incident scenario. 

In the first of the following subsections, the data coDection approaches adopted in most CPI incident reporting systems will be described. The fact that these systems provide little support for systematically gathering data on underlying causes will provide an introduction to the later sections which emphasize causal analysis techniques. 

Contamination generally poses the most important problem in ultra-trace analysis. It causes fluctuations of the blank values, thus defining the lower limits of detection, but also introduces systematic inaccuracies. Tracer techniques can be used to study the sources of contamination reagent blanks, vessel walls, airborne pollutants, etc. 

Failure Mode and Ejfect Analysis (FMEA) This is a systematic study of the causes of failures and their effects. All causes or modes of failure are considered for each element of a system, and then all possible outcomes or effects are recorded. This method is usually used in combination with fault tree analysis, a quantitative technique. FMEA is a comphcated procedure, usually carried out by experienced risk analysts. 

Different analytical procedures have been developed for direct atomic spectrometry of solids applicable to inorganic and organic materials in the form of powders, granulate, fibres, foils or sheets. For sample introduction without prior dissolution, a sample can also be suspended in a suitable solvent. Slurry techniques have not been used in relation to polymer/additive analysis. The required amount of sample taken for analysis typically ranges from 0.1 to 10 mg for analyte concentrations in the ppm and ppb range. In direct solid sampling method development, the mass of sample to be used is determined by the sensitivity of the available analytical lines. Physical methods are direct and relative instrumental methods, subjected to matrix-dependent physical and nonspectral interferences. Standard reference samples may be used to compensate for systematic errors. The minimum difficulties cause INAA, SNMS, XRF (for thin samples), TXRF and PIXE. 

From the case studies reported in this chapter, it has been shown that a systematic approach to failure analysis and contamination issues can be applied to a broad and diverse range of industrial problems. The use of techniques such as SEM, NMR, and FTIR can often provide information relevant to the cause of... 

Activation analysis is a blank-free technique. In general, blanks not oiJy determine the limits of detection, but at low concentrations they cause the main problems with respect to accuracy, because the small amounts to be determined have to be conveyed through all the steps of the chemical procedures, from sampHng to detection, without introducing systematic errors. These problems are not encountered in activation analysis, because contamination by other radionucHdes can, in general, be excluded and losses of the radionuclides to be determined can easily be detected by activity measurements. 

However, it must be kept clear in mind that direct instrumental detection methods for trace substances are physically relative methods which require calibration, during which systematic errors, caused for instance by spectral and nonspectral interferences, may occur. Relative methods are in fact matrix-dependent and would require the analysis of Certified Reference Materials (CRMs) in order to guarantee the good quality of the analytical data. Unfortunately, CRMs are not available for polar snow and ice and hence the only way to assure the quality of the data is, whenever possible, to make careful intercomparisons of the techniques able to measure the same analytes with different approaches. 

Alloy systems have been known to man since the Bronze Age. It is, however, only in recent times that they have been the subject of systematic studies, and in these studies no tool has proved more powerful than the technique of crystal structure analysis. Indeed, the extension of our knowledge and understanding of the properties of intermetallic systems to which it has given rise is one of the greatest achievements of crystal chemistry. Prior to the application of X-ray methods, the investigation of the properties of alloy systems was confined principally to observations of their behaviour in the liquid state, and the behaviour of the metal as a solid could be determined only by inference from these observations. Transitions in the solid state and the effect of mechanical or heat treatment could not, of course, be observed in this way, and for information on these properties the microscope and other purely physical methods had to be invoked. Even so, these methods were all more or less indirect, and it is only since the application of X-ray analysis that it has been possible to investigate directly in the solid state, under the precise conditions which are of technical interest and without damage to the specimen, the exact positions of all the atoms in the structure, and so to refer to their ultimate cause the physical and chemical properties of the alloy. 

Fault trees are commonly used in safety critical industries such as aerospace. Their power is in being able to communicate complex failures in a simple graphical format which is relatively easy to learn. They can be applied to either potential failures or retrospectively in investigating actual failures. FTA has subtle limitations however especially when one needs to systematically identify aU possible causes of a particular hazard - for this, an alternative technique needs to supplement the analysis. Fault trees are also notoriously difficult to apply to complex software. 

Advanced investigation methods adopted by USA in accident investigation, such as systematic analysis of causes and accident roadmap, are learnt, field detection, computer simulation and all kinds of modem test techniques are comprehensively utilized the scientificalness and correctness of the investigation results. 

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