Failures avoiding

Common-mode failure Avoid common-mode failure possibilities with services, control systems, safety systems etc. 

Enalaprilat 1.25-5 mg every 6 hours 1 5-30 minutes 6-12 hours Precipitous fall in pressure in high-renin states variable response Acute left ventricular failure avoid in acute myocardial infarction... 

Hepatic function impairment Elevations of hepatic enzymes and hepatic failure have been reported in association with dipyridamole administration. Dipyridamole can be dosed without restriction as long as there is no evidence of hepatic failure. Avoid aspirin in patients with severe hepatic insufficiency. 

Cardiac failure Avoid use in overt CHF may be used with caution in patients with a history of heart failure who are well compensated. CHF has been observed in patients receiving labetalol. 

Bicarbonate, sodium Membrane-depressant cardiotoxic drugs (tricyclic antidepressants, quinidine, etc) 1-2 mEq/kg IV bolus usually reverses cardiotoxic effects (wide QRS, hypotension). Give cautiously in heart failure (avoid sodium overload). 

Pennyroyal Digestive aid induction of menstrual flow abortifacient Pulegone and pulegone metabolite, liver failure, renal failure Avoid... 

Diuretics Indometacin Reduction in natriuretic and diuretic effects can exacerbate congestive cardiac failure Avoid NSAIDs in patients with cardiac failure use sulindac monitor clinical signs of fluid retention... 

While the benefits of detecting abnormal machine wear or an aging lubricant condition are important and frequently achieved with oil analysis programs, they are of low importance when compared to the more rewarding objective of failure avoidance. This is achieved by treating the causes of failure, not just the symptoms. Also, it is the foundation of the popular practice known as proactive maintenance. 

Change the type of mechanical seal (not so complex as the previous) and provide a minimum stock to face possible failures avoiding the time lost to contact the suppher and to wait for equipment delivery ... 

The case studies have illustrated how fundamental assumptions can he proved wrong and how multiple-level redundant systems can fail, especially when applied to human behaviour. Application software is seen to be particularly vulnerable in this regard, as was shown at Milton Keynes. Most if not all of the techniques and measures aimed at systematic failure avoidance involve human behaviour, where error rates ( failures ) are known to be much greater than those for physical devices. In the author s opinion this is where the effort should be directed. 

Landau, M., and Chisholm, D. 1995. The arrogance of optimism notes on failure avoidance management. Journal of Contingencies and Crisis Management 3, 67-80. 

Liver failure Avoid TACE in patients with Child-Pugh C liver disease. Do not perform TACE from proper hepatic artery. Select right or left. May be irreversible and fatal... 

A common SLCM shall fulfill all necessary requirements of the safety standard (lEC 61508). Additionally it should be compliant with the E/E/PES and software safety lifecycles recommended in lEC 61508. It should show that the failure avoidance and... 

A SLCM consists of a set of phases. As we built upon the structure of the SLCM recommended by lEC 61508 our SLCM has the same number of phases as the one from lEC 61508. Similar to lEC 61508 a phase of our SLCM has objectives, description, inputs, outputs and the related safety integrity measures for failure avoidance recommended by lEC 61508, which shall be selected or equivalently substituted according to the safety integrity level to be achieved. In addition, we added detailed activities, documentation, verification, verifier, executor and knowledge Experience as extension to the related phases. Those additional SLC components are not included in the SLCM from lEC 61508, however they are necessary because a safety development team can save a lot of effort through such kind of support. In addition a phase is associated with the related design elements (as shown in Fig. 3), which help to manage the product complexity and to specify the outputs of that phase. 

The safety integrity measure covers the measures that are required to fulfill the safety integrity requirements. Selection and implementation of the safety integration measures depends on the safety integrity level to be achieved. For us the question was how to structure and organize those failure avoidance measures and incorporate them into our SLCM. As our SLCM uses the same structure and phases as the one of IFC 61508, it is quite easy to realize the incorporation. All measures are associated to the same phases similar to the SLCM of IFC 61508. Incorporation of the failure avoidance measures into a SLCM makes it different from a normal development lifecycle model. 

Conformance Use of the structure and phases of the SLCM of lEC 61508 Incorporation of the failure avoidance measures The activities dented fulfill the requirements Our SLCM is checked by TUV in the context of the certification of FSM Add-on [6], which includes SLCM and FSM plan... 

Management of functional safety Incorporation of our SLCM into the FSMplan, i.e. SLCM is part of the FSM plan. Our SLCM also supports definition of inputs and outputs, selection of failure avoidance measures, and selection of the documentation approaches... 

Selection of the documentation approaches and the related templates Selection of the failure avoidance measures based on the SIL to be achieved. 

Adapting the SLCM normal needed several days. The effort heavily depended on the competence of the participating people. We have observed that most of the effort was spent on the selection and discussion of the failure avoidance measures, followed by adaptation of the phases, PDM and documentation approaches. 

This approach to using multiple components is based on the fact that NASA experience indicates the prudence of having redundant components, even if they have demonstrated reliability, to ensure that manufacturing defects or human error does not lead to a mission ending failure. For those components where redundancy is considered impractical, exceptions to the single point failure avoidance requirement is provided. For the... 

The principles of remaining sensitive to front-line operations, focusing on failure, avoiding oversimplification, organising around expertise and continually aiming for resilience (Weick and Sutcliffe, 2001), provide... 

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