Reliability case studies

The press had been designed with a capacity to deliver 280 kN press force and to work at a production rate of 40 lids per minute. Calculations to determine the distribution of forming loads required indicated that the press capacity was adequate to form the family of steel lids to be produced on the machine. One of the major areas of interest in the design was the con-rod and pin (see Figure 4.66). The first option considered was based on a previous design where the con-rod was manufactured from cast iron with phosphor bronze bearings at the big and small ends. However, weaknesses in this approach necessitated the consideration of other options. The case study presents the analysis of the pin and con-rod using simple probabilistic techniques in an attempt to provide in-service reliable press operation. The way a weak link was introduced to ensure ease of maintenance and repair in the event... 

This book brings together a wide range of tools and techniques used by human factors and human reliability specialists, which have proved to be useful in the context of human performance problems in the CPI. Although many human factors practitioners will be familiar with these methods, this book is intended to provide ready access to both simple and advanced techniques in a single source. Where possible, uses of the techniques in a CPI context are illustrated by means of case studies. 

Despite the lack of interest in human factors issues in the CPI in the past, the situation is now changing. In 1985, Trevor Kletz published his landmark book on human error in the CPI An Engineer s View of Human Error (revised in 1991). Several other books by the same author e.g., Kletz (1994b) have also addressed the issue of human factors in case studies. Two other publications have also been concerned specifically with human factors in the process industry Lorenzo (1990) was commissioned by the Chemical Manufacturers Association in the USA, and Mill (1992), published by the U.K. Institution of Chemical Engineers. In 1992, CCPS and other organizations sponsored a conference on Human Factors and Human Reliability in Process Safety (CCPS, 1992c). This was further evidence of the growing interest in the topic within the CPI. 

THE ROLE OF HUMAN RELIABILITY IN RISK ASSESSMENT 5.2.1. An Illustrative Case Study... 

Because most research effort in the human reliability domain has focused on the quantification of error probabilities, a large number of techniques exist. However, a relatively small number of these techniques have actually been applied in practical risk assessments, and even fewer have been used in the CPI. For this reason, in this section only three techniques will be described in detail. More extensive reviews are available from other sources (e.g., Kirwan et al., 1988 Kirwan, 1990 Meister, 1984). Following a brief description of each technique, a case study will be provided to illustrate the application of the technique in practice. As emphasized in the early part of this chapter, quantification has to be preceded by a rigorous qualitative analysis in order to ensure that all errors with significant consequences are identified. If the qualitative analysis is incomplete, then quanhfication will be inaccurate. It is also important to be aware of the limitations of the accuracy of the data generally available... 

Kontogiarmis, T., Lucas, D. (1990). "Operator Performance Under High Stress An Evaluation of Cognitive Modes, Case Studies and Coimtermeasures." Report No. R90/03 prepared for the Nuclear Power Engineering Test Center, Tokyo. Human Reliability Associates, Dalton, Wigan, Lancashire, UK. 

Murgatroyd, R. A., Tait, J. F. (1987)."A Case Study of the Application of the SHERPA Technique to the Dinorwig Spiral Casing Ultrasonic Testing System." Human Reliability Associates, 1 School House Higher Lane, Dalton, Wigan, Lancs., UK. 

Given that there were numerous alternatives for the resources, including demand-side management, interruptible loads, and off-system purchases, many case studies were ncccssai y. Each plan for service to future loads had to be tested for conformance with system and regional reliability criteria. The plans were further examined for cost, including losses, and examined for flexibility. Any acceptable plans had to... 

Case Study - Reliability of a Horizontal Well Performance... 

On the other hand, in part II of this volume, a set of case studies are introduced. The application of the selected methodologies inside each one of the foresaid disciplines (e.g., risk assessment, life cycle assessment) to specific cases and countries is presented here. The results of such application are discussed as well as their reliability. Toxicological studies in Italy, risk assessment of electronic waste in China, or disposal of bearing lamps in India are some examples of selected scenarios. 

The case study described here shows that emissions of chemicals, including substances that might be considered as additives in the printed matter life cycle, may contribute significantly to the LCA impact profile. In order to increase the reliability of this result, confirmation, by use of newer and improved LCIA methodology and updated LCI data for the background processes, are desirable. Newer LCIA methodology has actually been used in other LCA studies on printed... 

Section 5.1 is based on a paper by Sonnemans P.J.M., Korvers P.M.W., Brombacher A.C., 2004. Effective Safety management - A case study in the chemical industry, Quality Reliability Engineering International VoL 20 (2), pp. 

Hepatic Effects. Liver effects reported in case studies in humans exposed to 1,4-dichlorobenzene via inhalation have included jaundice, cirrhosis, and atrophy (Cotter 1953). Estimates of exposure duration ranged from 1 to 18 months however, quantitative data on 1,4-dichlorobenzene levels were not available. One report was located that described a 3-year-old boy who may have ingested 1,4-dichlorobenzene crystals. Jaundice was reported, indicating that liver function was in some way compromised, although no further details were reported. No dermal exposures to 1,4-dichlorobenzene in humans were reported. The lack of reliable information regarding human exposures to 1,4-dichlorobenzene by all three routes of exposure makes it difficult to draw any helpful conclusions about the toxicity of 1,4-dichlorobenzene in humans. 

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