Safety failures

It would be comforting to be able to state that the causes of postmarketing withdrawals from drugs were substantially different from those of failure of drugs in clinical trials. While the last few years (refer back to Table 1.1) are seemingly somewhat different from those in the past, the historic causes for the modem era (the last 40 years) are lead off by hepatic toxicity, also the primary cause for safety failure in early clinical trials. 

The sponsor should consider evaluating forced degradation products in animal studies to determine if they present a toxicity issue, and, if so, an appropriate limit to ensure safety. Failure to identify toxic degradation products early in the development program can be costly mistake if the drug has to be abandoned later because of potential toxicity concerns. 

Finally, it must be stressed that designers, suppliers, and installers of each of the three main elements the chemically-resistant masonry, the membrane and the wooden support must cooperate, discussing and agreeing on the total final design so that the diverse properties of the materials are combined for maximum economy, performance and safety. Failure to obtain such agreement can result in the failure of any structure created by the marriage of such diverse elements. 

Car BD. Enabling technologies in reducing drug attrition due to safety failures. American Drug Discov 2006 1 53-56. 

Car BD. Enabling Technologies in Reducing Drug Attrition Due to Safety Failures. Am Drug Discov 2006 1 53-6. 

Tolerances are also not well understood. A fuel cell stack with over 400 cells operating in this environment contains sealant, which is literally miles long. Seals will start to fail after the fuel cell is bumped and jostled on the highway and while temperature shifts between hot and cold, and the cell is turned off and on. With zero tolerance for safety failures, hydrogen leaks cannot occur with these vehicles. Additionally, every cell has to be identical or the system cannot be managed. Unfortunately, that kind of tolerance control is not yet available. 

The petroleum industry is of course engaged in safety aspects of its activities for several other reasons than compulsory state requirements the level of eompensa-tion for damages caused by safety failures may call for increased efforts laid into... 

An injury is one of the many possible outcomes of an accident and is the most prominent consequence. It is tallied and used as a measure of safety effort, safety failure, or safety success. An (accidental) injury is defined as the bodily hurt sustained as... 

Traditional thinking is that the main measure of safety failure or success is the injury rate, while new thinking is that there are multiple ways to measure safety (Figure 8.1), including ... 

Both measures of harm and assessments of failures in the process of care may reflect overall levels of safety. Failure to give appropriate care may or may not lead to harm, but it certainly seems reasonable to class these failures under the general heading of safety. These process measures however, seem similar if not identical to broader quality measures of effectiveness, reliability and efficiency captured in numerous studies of the quality of care. Does this mean that safety measures are nothing more than quality measures under another name Not exactly, though when we examine the level of process rather than outcomes, the same measures may reflect both safety (in the sense of potential for harm)... 

Many other models and tools were presented as well for maintenance HF treatment. Examples include INDICATE, a program launched by the AustraUan Transport Safety Bureau (ATSB 1999) in the late 1990 s. which was preceded by a number of proactive tools (Reason 1996) which were intended to monitor organizational latent conditions that may give rise to safety failures. Also developed were the... 

Requirements for weapons and ammunition design safety are sufficiently elaborated and described in literature (Allsop, D. et al. 1997, Balia Fiser 2008, Beer et al. 2004, Fiser Balia 2004) and in standards today. On the other hand, the requirements for risks of safety failure of small arms and their ammunition have not been published and elaborated yet. No absolute guarantee of safety can ever be given. Therefore it is necessary to determine an acceptable level of safety risk in requirements for both new weapon and new ammunition. 

Power and control systems associated with containment isolation are multichaimel, fail-safety. Failure of a single sensor circuit or system component does not prevent normal protective action. Separate routes from different, reliable power sources feed two valves in the same line. Control power and motive power for an electrically operated valve are supplied from the same source. 

Actual prosecution of principal contractors following safety failures is also, on occasion, a force for safety, for it can raise in the minds of company directors the possibility that they may be personally prosecuted for breaches of the legislation or even for manslaughter. According to one constmction company safety officer 1 spoke with, this fear of personal liability was a significant factor in safety improvements which occurred following a constmction collapse and associated prosecution. 

The LTI frequency rate is not a reliable indicator of the level of safety at Eastern, in part because of the extent to which it is influenced by claims management procedures which result in the conversion of LTIs into injuries without lost time. A further defect is that it fails to highlight major safety failures which need to be taken seriously, regardless of how many lost-time injuries may be occurring. For instance, fatalities are relatively rare, and most mines go for years without a death. However, when they occur they are usually indicative of serious safety deficiencies. Moreover, there are certain kinds of dangerous occurrences with the potential to lead to death or injury which must be reported to the inspectorate, regardless of whether injury has in fact occurred. Every such dangerous occurrence raises questions about standards of safety. 

One safety-conscious company I visited had just had a major safety failure. It had always believed in management responsibility for safety, but this it turned out had not had the intended impact on the thinking of middle managers. Following the failure the company therefore adopted a policy of management accountability, which meant that managers salaries and even careers would henceforth be affected by their safety performance. This, it was hoped, would lead to even higher standards of safety. 

HFT, hardware fault tolerance SFF, safety failure fraction. 

PFDavg, probability of failure on demand PTI, proof test interval SFF, safety failure fraction SIL, safety integrity level. 

Architectural constraint Associated factors Safety failure fraction (SFF) and hardware fault tolerance (HFT)... 

Certification Both products and processes can receive such a certification. Certification for the former is most common and is issued by an independent agency to show that the appropriate SIL calculations have been performed and analysis has been completed on a product. Self-certification, though not common, is also possible. Such certifications are used to signify that it is compatible for use within a system up to the certified SIL. As discussed earlier, FMEDA is normally used to determine the safe/unsafe and detected/undetected failure modes of a product. FMEDA is useful for calculations of safety failure fraction and PFD. Although not common, full certification of lEC 61508 is also possible for manufacturer s design and quality processes. 

My hope is to use this study to better understand the processes that allow organizations to slide into disasters and failures, and why it may be difficult to recognize, learn from, and intervene in these processes in order to arrest the slide. I use the notion of the safety failure cycle as a main theoretical framework (e.g., Heimann, 1997 Reason, 1997). I follow my theoretical discussion with a narrative that describes the experiences of the shuttle program and the JPL. Following my analysis of these experiences I conclude with some implications for theory and practice. 

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