Analysis of Key Factors

The DuPont Company has faith in a process called the Analysis of Key Factors for incident investigation. In early 1998, in a small article entitled Getting to the Root of the Problem—The Importance of Incident Investigation appeared in DuPont s Executive Safety News. This article stresses the role of senior management in incident investigation. 

The most common process used today is Analysis of Key Factors. According to this process, all different speculative causes from a number of different elements (such as equipment, people, systems, processes, etc.) are examined for their possible role in the incident. 

The most common process used today is Analysis of Key Factors. According to this process, all different speculative causes from a number of different elements (such as equipment, people, systems, processes, etc.) are examinedfor their possible role in the incident. Once the cause, or causes have been pinpointed, why and/or how they contributed to the incident must be determined. For example, if an equipment is to blame, the next question to answer is Why weren t we aware of this defect before the equipmentwasput in service.... ... 

Tier 0 analysis may be done just once, but not repeated for every individual assessment. Even though Tier 0 assessments are practical to conduct, they are not suited for addressing problems that require a realistic identification of key factors and exposure conditions contributing to assessment outcomes and uncertainties. Higher-tier assessments are often needed to answer such questions. 

Vivarelli M, Cucchetti A, Piscaglia F, La Barba G, Bolondi L, Cavallari A, Pinna AD. Analysis of risk factors for tumor recurrence after liver transplantation for hepatocellular carcinoma key role of immunosuppression. Liver Transplant 2005 11 497-503. 

It is apparent from section 2.5 that many factors influence the course of nucleophilic reactions, including the nature of the nucleophile, its strength, the solvent, the substrate and the nature of the leaving group. When substitution (sec. 2.7.A,B) and elimination (sec. 2.9.A,B) are discussed, it will be noted that they are sometimes competitive when using nucleophiles that are also bases, such as hydroxide. The same factors mentioned above influence the extent of this competition. If the functional groups in a molecule were such that substitution and elimination were competitive processes, then a mixture of products could result. It would be very useful to have a list of parameters for such situations that allow one to make predictions. This section will focus on several factors that influence both nucleophilic and elimination reactions. Analysis of these factors lead to key assumptions and predictions of the major product in many cases. 

Developing specifications for systemwide power-conditioning/backup hardware requires careful analysis of various factors before a particular technology or a specific vendor is selected. Key factors in this process relate to the load hardware and load application. The electrical power required by a sensitive load may vary widely, depending on the configuration of the system. The principal factors that apply to system specification include the following ... 

Gorensek MJ, Stewart RW, Keys TF, Mehta AC, McHenry MC, Goormastic M. A multivariate analysis of risk factors for pneumonia following cardiac transplantation. Transplantation 1987 46 860-865. 

As can be seen from this analysis, the natural gas feedstock and capital charges amount to over 93% of the total production cost before return on investment. Therefore, energy consumption and capital investment are the key factors in determining ammonia production profitabiUty. 

We now consider a type of analysis in which the data (which may consist of solvent properties or of solvent effects on rates, equilibria, and spectra) again are expressed as a linear combination of products as in Eq. (8-81), but now the statistical treatment yields estimates of both a, and jc,. This method is called principal component analysis or factor analysis. A key difference between multiple linear regression analysis and principal component analysis (in the chemical setting) is that regression analysis adopts chemical models a priori, whereas in factor analysis the chemical significance of the factors emerges (if desired) as a result of the analysis. We will not explore the statistical procedure, but will cite some results. We have already encountered examples in Section 8.2 on the classification of solvents and in the present section in the form of the Swain et al. treatment leading to Eq. (8-74). 

A key factor in determining an ROI on the basis of increased efficiencies is to be able to apply metrics to the existing processes commonly this requires measurement of the process before the implementation of a new system and then a corresponding measurement of the process after implementation. In the case of ELN systems, this information can also be supplemented through the use of the ELN database itself, for example, by looking at the number of completed experiments created per scientist per week. These data can then be compared with an historical analysis of data from paper notebook archives on scientific productivity by similar groups. 

From an analysis of the key properties of compounds in the World Dmg Index the now well accepted Rule-of-5 has been derived [25, 26]. It was concluded that compounds are most Hkely to have poor absorption when MW>500, calculated octanol-water partition coefficient Clog P>5, number of H-bond donors >5 and number of H-bond acceptors >10. Computation of these properties is now available as a simple but efficient ADME screen in commercial software. The Rule-of-5 should be seen as a qualitative absorption/permeabiHty predictor [43], rather than a quantitative predictor [140]. The Rule-of-5 is not predictive for bioavail-abihty as sometimes mistakenly is assumed. An important factor for bioavailabihty in addition to absorption is liver first-pass effect (metaboHsm). The property distribution in drug-related chemical databases has been studied as another approach to understand drug-likeness [141, 142]. 

In considering the retrosynthetic analysis of juvabione, two factors draw special attention to the bond between C(4) and C(7). First, this bond establishes the stereochemistry of the molecule. The C(4) and C(7) carbons are stereogenic centers and their relative configuration determines the diastereomeric structure. In a stereocontrolled synthesis, it is necessary to establish the desired stereochemistry at C(4) and C(7). The C(4)-C(7) bond also connects the side chain to the cyclohexene ring. As a cyclohexane derivative is a logical candidate for one key intermediate, the C(4)-C(7) bond is a potential bond disconnection. 

The key factor in voltammetry (and polarography) is that the applied potential is varied over the course of the measurement. The voltammogram, which is a current-applied potential curve, / = /( ), corresponds to a voltage scan over a range that induces oxidation or reduction of the analytes. This plot allows identification and measurement of the concentration of each species. Several metals can be determined. The limiting currents in the redox processes can be used for quantitative analysis this is the basis of voltammetric analysis [489]. The methods are based on the direct proportionality between the current and the concentration of the electroactive species, and exploit the ease and precision of measuring electric currents. Voltammetry is suitable for concentrations at or above ppm level. The sensitivity is often much higher than can be obtained with classical titrations. The sensitivity of voltammetric... 

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