Use of Statistical Methods

These improvements are more likely to occur at the program and element level. For example, at one chemical company a group of senior operators took an initiative to redesign the work permit process that reduced the number of forms required, reduced the time required to issue a permit from an average of two hours to 30 minutes and improved the workplace monitoring needed to ensure a safe work environment. The reduction in the time to issue permits increased maintenance productivity by at least 10 percent, by reducing maintenance worker time spent waiting for permits. This more responsive system also reduced the number of instances where work went ahead without the appropriate permit. 

Tlie training system itself should also be subject to continuous improvement, particularly in light of the key role it has in ensuring the success of the integration efforts and in achieving overall performance. 

The analysis of performance provides a powerful technique for identifying potential for improvement. As discussed in the previous chapter, trends can be spotted and action taken to identify and correct any unwanted development. Additionally, analysis of data can help with the identification of underlying problems. For example, a higher than average number of eye injuries at a particular facility might justify further investigation. 

One major oil and chemical company has collected data on the cost of accidents, the equipment involved and the cause of the failure for more than 50 years. These data are analyzed annually to help decide where to focus efforts to reduce losses and/or to modify design standards to prevent recurrence. This analysis also identifies failures of the PSM and ESH management system. These can be compared with the cost of delivering the systems and adjustments made to expenditures to improve the cost/benefit balance. Any such changes must be carefully considered as normal statistical variation may cause you to take unjustified action. 

---

Quality documentation and records Use of statistical methods Economics Auditing... 

Use of statistical methods Follows logically from establishing quality records. 

Use of statistical methods requires that performance be analyzed to identify weaknesses and strengths. Weaknesses can be addressed and strong systems used as models for improvement. 

Correctly used, statistics is an essential tool for the analyst. The use of statistical methods can prevent hasty judgements being made on the basis of limited information. It has only been possible in this chapter to give a brief resume of some statistical techniques that may be applied to analytical problems. The approach, therefore, has been to use specific examples which illustrate the scope of the subject as applied to the treatment of analytical data. There is a danger that this approach may overlook some basic concepts of the subject and the reader is strongly advised to become more fully conversant with these statistical methods by obtaining a selection of the excellent texts now available. 

We hope by presenting this forum that ideas can flow from readers to aid in a fuller understanding and use of statistical methods. We hope we can use such methods in our laboratories and spread to other parts of society a greater appreciation and understanding of them. 

In simple terms, meta-analysis is the practice of using statistical methods to combine and quantify the outcomes of a series of studies in a single, pooled analysis. What is crucial in this definition is the emphasis on the use of statistical methods. In most biomedical research, the scientific review has a lengthy history and is still widely used. However, insofar that it does not utilise statistical methods for pooling results, and tends to summarise more in qualitative rather than quantitative terms it cannot be regarded as meta-analysis. 

However, a quantitative evaluation, i.e, an exact determination of the r/0-parameter pairs for each nucleus in the solute, is not easy252. It should be determined only by the use of statistical methods to obtain reliable structural assignments, as shown for the four diastereomeric 1-cyano-2-ethylidene-3-methylcyclopropanes253. Quantitative evaluation is even more complicated if the solute is conformationally mobile, because a careful conformational analysis is the basis of any sound interpretation of LSR experiments. Moreover, the conformational equilibrium of the solute may change in the presence of LSR. 

The use of statistical methods should help furnish insight into fundamental mechanisms underlying the behaviour patterns of the... 

Furthermore, it has been clearly pointed out [127] that, once a large number of experiments of more or less arbitrary design have been performed, a posterior use of statistical methods of data treatment can no longer guarantee a result of reliable value, because... 

The unstable nuclei in a radioactive sample do not all decay simultaneously. Instead, the decay of a given nucleus is an entirely random event. Consequently, studies of radioactive decay events require the use of statistical methods. With these methods, one may observe a large number of radioactive nuclei and predict with fair assurance that, after a given length of time, a definite fraction of them will have disintegrated but not which ones or when. 

It is apparent from an examination of the literature that there have been few attempts to make use of statistical methods in the quantitative recognition... 

In the past five years, there has been extensive use of statistical methods to recover signals partially obscured by noise (see the chapter by Godsill, Rayner and Cappe). 

A second and distinct era in the development of branched macromolecular architecture encompasses the time between 1940 to 1978, or approximately the next four decades. Kuhn 151 published the first report of the use of statistical methods for analysis of a polymer problem in 1930. Equations were derived for molecular weight distributions of degraded cellulose. Thereafter, mathematical analyses of polymer properties and interactions flourished. Perhaps no single person has affected linear and non-linear polymer chemistry as profoundly as P. J. Flory. His contributions were rewarded by receipt of the Nobel Prize for Chemistry in 1974. 

An important principle that underpins the use of the 5-point ideal standard is that checking compliance with numerical standards is a statistical process. This requires that a standard is defined in terms that allow the use of statistical methods, typically... 

Use of statistical methods to enhance and maintain quality at all stages and of all activities in the product cycle. 

The monitoring of analytical quality by the use of statistical methods and control charts. 

To be able to discern whether or not a change in the experimental conditions will produce a systematic change in the measured response, the systematic variation, which is described by /, must be above the noise level described by e. The presence of an error component in all experimentally determined data necessitates the use of statistical methods in the evaluation of experiments. In the next chapter, we shall see that useful approximations of the function f can be established which will make it possible to determine the influence of each experimental variable, Xj, on the response y. 

---