Technical failure

Equipment part Problem Diagnosis Corrective action 

Gradient Leakage Wrong gradient composition- Check tightness and 

Injection Wrong Wrong injected volume- Check flow rate. 

Eluent Wrong when flow rate is controlled by a flow Check frequency 

Detector No signal Check UV light intensity Change UV light 

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Many data collection systems place the primary emphasis on the technical causes of accidents. There is usually a very detailed description of the chemical process in which the accident occurred, together with an in-depth analysis of the technical failures that are seen as the major causes. The human or system failures that may have contributed to the accident are usually treated in a cursory manner. Technically oriented reporting systems are very common in the CPI, where engineers who may be unfamiliar with human factors princi-... 

This is mainly applicable to equipment and other technical failures. It also considers areas such as loss of containment, environmental impact, fires, and explosions. 

All decisions must be recorded, as well as an explanation of the decision, to provide background information if changes are needed in the future. Also, all monitoring activities must be documented, so that it is clear who has done what and when. The documentation is used to demonstrate compliance in relation to certification, and in case of problems it is used to try to find out if a problem was due to human error or a technical failure. 

A very important contribution in this socio-technical era is made by Reason (Reason, 1990). He made a distinction between active failures, and latent conditions. The active failures are in general failures made by those at the sharp end of the accident causation (e.g. technical and human failures). Effects are felt almost immediately. Latent conditions are removed in time and space from the sharp end of the accident causation (e.g. organizational and technical failures) creating conditions for active failures to be made. A strict boundary between both concepts cannot be made and in reality can be seen as a sort of sliding transition. Here, the two concepts are separated... 

Highly sensitive. Useful for retrieving technical failures in immunocytochemistry. 

SNH - deals with an undesirable event caused by non-human actions, deals with physical environment, like fire, flood, earthquake, different disturbances or technical failures ... 

As technology progresses the safety of man-machine systems depends more and more on the quality of the human component (operator). This fact is very obvious in transportation, where the operator (driver) is formally and actually in control of his or her vehicle. In aviation, however, a strong trend towards software control of the aeroplane is already becoming dominant, forcing the operator (pilot) primarily into the role of supervisor or monitor of the automatic control system and into that of trouble-shooter in case of (technical) failure. In this respect a cockpit crew is facing the same situation as for instance a shift of operators in the central control room of a completely computerised chemical process plant. 

Technical Failures (TE, TC) point at technical improvements of the equipment, also S B errors, because of their automatic nature, can best be prevented by changing the work environment, not by changing the person. 

Technical failure coded as Design Engineering (DE), Design Construction (DC) or Design Other (DX). 

Paragraph 1 explains the rationale under which traceability is established. It should be noted here that all the stakeholders are expected to benefit from the introduction of the Article public authorities, because of facilitation of control, manufacturers and users of food contact products, who will benefit from recall and easier attribution of responsibility, and finally a stricter regulation of traceability would give additional reassurance to consumers. As stated above, the main reason for traceability procedures having been introduced by food contact materials producers was related to defective product recall, i.e., linked to potential technical failure of them, rather than health hazards (that are extremely unlikely). Therefore such a paragraph can be interpreted as a measure of prevention that is not deemed to bring extra safety factors to the final consumers. 

The application of an artificial endocrine pancreas (AEP=Biostator) with feedback control could be useful in the clinical management of unstable diabetics (Ohno et al., 1983). Former early closed-loop devices were large bedside machines (Pfeiffer et al., 1974) with only limited application for long-term use. More recent research has developed small glucose sensors which, however, have had only preliminarily testing for clinical application. External insulin pumps must be further miniaturized and technical failure... 

FIGURE 14.11 Vertical flux of particulate organic nitrogen into a sediment trap located at 180-m water depth at station BMP J1 in the central Gotland Sea. Note that in the first 2 years some periods are missing because of initial technical failures of the instrument. 

Eirst, the extension primers for the SNP of interest were tested on seven replicates of individual genomic DNA samples to determine if the individual is heterozygous for the SNP. Before subsequent statistical analyses, obvious technical failures or statistical outliers were eliminated. Eor the individual who is heterozygous for the SNP, the ratio of the magnitude of the peak heights from the two nucleotides at the same sequencing position was calculated. The average ratio from the seven replicates was then derived. 

For assays performed on the cDNA, the fractional allelic experiment for each sample was also determined through seven replicates and obvious technical failures or statistical outliers were eliminated. The allelic ratio of expression based on the magnitudes of SNP peak heights were determined. Each individual s average allelic differential expression ratio value can be normalized based on the average allelic ratio derived from the same individual s genomic template. 

The top line of the index is an expected net present value which takes account of the sequential nature of the decision-making process and thus captures (unlike indices based on totals only) the value of the option to abandon given technical failure which the developer holds. (Note that this option is not held if the stages are done in parallel.) The bottom line is used to scale projects according to their investment requirements. 

A chromatography equipment is quite complex and many technical failures may happen when operating a preparative device. Most of the time, a technical problem is directly visible or even detected by the system if this one is automated. 

This section is divided into three parts the first one will describe the main technical failures that occur in the process, give the way to diagnose the failure, and the way to troubleshoot it. In a second part, we will examine the loss of performances that can be observed on a system, list the most probable root causes, and the way to... 

Table 4.15 describes technical failures that may happen in chromatographic systems. 

Table 4.15 Possible technical failures in a chromatography system.

Solvent composition of the eluent Most of the chromatographic separation uses a binary solvent mixture for the separation and sometimes a buffer solution. A wrong solvent preparation could lead to a wrong composition and therefore modify the retention of the products. A technical failure of the gradient module could also disturb retention. 

Time constraints and high risk may also add up, thus increasing the difficulty of fault diagnosis. A particularly demanding situation is dynamic fault management (Woods 1994), whereby operators have to maintain system functions despite technical failures or disturbances. Typical fields of practice... 

In the case of continuously operated single-purpose plants the set of input and output chemicals is fixed (i.e. there is only one recipe used). However, the throughput of the plant can vary in most cases. I.e. there is a finite set of production modes each one associated to specific flow levels of all chemicals. As such plants are typically designed for maximal efficiency, the production mode associated with the maximum throughput is the intended state of production. A change to another mode is often forced by disturbances such as technical failures. ... 

Unloading and loading times (in hours) are normally distributed random variables with N(2, 0.25). The total turnover capacity depends on the number of transfer arms available and the number of operating hours. Turnover operations take place 10 hours per day from Monday to Saturday. Due to strikes, technical failures, etc. operating hours may reduce to 5 or 0 hours. A discrete Markov model is used to model these disturbances constituted by the following transition matrix ... 

Even if a technical failure precedes the human action, the tendency is to put the blame on an inadequate response to the failure by an operator. Perrow claims that even in the best of industries, there is rampant attribution of accidents to operator error, to the neglect of errors by designers or managers [155], He dtes a U.S. Air Force study of aviation accidents demonstrating that the designation of human error (pilot error in this case) is a convenient classification for mishaps whose real cause is uncertain, complex, or embarrassing to the organization. 

The accident was thoroughly investigated including, to the Navy s credit, the systemic factors as well as the technical failures and deficiencies. Deep sea photography, recovered artifacts, and an evaluation of the Thresher design and operational... 

Kovalenko said three more trials would take place to establish who was responsible for technical failures in design and construction of the plant, for failings in evacuation and medical procedures, and for security errors after the accident. 

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