Failures inevitability

The closer one is to the failure, the more its direct effects are apparent. The cumulative effects of failure are often overlooked in the rush to fix the immediate problem. Too often, the cause of failure is ignored or forgotten because of time constraints or indifference. The failure or corrosion is considered just a cost of doing business. Inevitably, such problems become chronic associated costs, tribulations, and delays become ingrained. Problems persist until cost or concern overwhelm corporate inertia. A temporary solution is no longer acceptable the correct solution is to identify and eliminate the failure. Preventative costs are almost always a small fraction of those associated with neglect. 

Suppose a particular fault in a product is not detected through internal tests and inevitably results in a failure severity S = 5. If around 80% of failures are found by customer testing and 20% are warranty returns, then the expected cost on average for one fault will be 2.8Pc, from Figure 1.13. If the product has been designed such that Cpi = 1.33, or in other words, approximately 30 parts-per-million (ppm) failures are expected for the characteristic which may be faulty, then for a product costing 100 the probable cost of failure per million products produced would be 8400. 

Most ISO 9000 registered organizations claim to provide quality products and services, so why should there be so many dissatisfied customers when there are over 270,000 organizations in the world certified to ISO 9001, 9002, or 9003 One of the principal requirements in the standard is for the supplier to establish a quality system as a means of ensuring that product or service meet specified requirements. If an organization s products or services do not meet specified requirements then clearly the system has failed, but the failure is no fault of the standard - it is a fault of the way the standard has been applied and interpreted both by the organizations themselves and by the auditors who determine conformity. If the specified requirements are less than those of the customers, it is inevitable that products will bring dissatisfaction. This realization has, in the case of the automotive industry, led to two distinct needs ... 

It had been assumed that the operator would continue to watch the level and that the trip would take over on the odd occasion when the operator failed to do so. Coincident failure of the trip was most unlikely. However, the operator no longer watched the level now that he was supplied with a trip. The manager knew that he was not doing so. But he decided that the trip was giving the operator more time for his other duties. The trip had the normal failure rate for such equipment, about once in two years, so another spillage after about two years was inevitable. A reliable operator had been replaced by a less reliable trip. 

Management policies are the source of many of the preconditions that give rise to systems failures. For example, if no explicit policy exists or if resources are not made available for safety critical areas such as procedures design, the effective presentation of process information, or for ensuring that effective communication systems exist, then human error leading to an accident is, at some stage, inevitable. Such policy failures can be regarded as another form of latent human error, and will be discussed in more detail in Section 2.7. 

In considering the various theories it is also apparent that many of them may be considered as alternative descriptions of essentially the same physical process, or as descriptions of parallel processes which collaborate in the failure. Thus a complete description of hydrogen embrittlement in a given situation will almost inevitably incorporate aspects of several of the following theories. 

It practice it is usually difficult to establish the reasons for failure as a number of factors may be simultaneously responsible, such as (n) application of the protective to dirty surfaces, (b) carelessness in application, (c) inherent inadequacy of the material, (rf) exposure to unreasonably severe conditions, (e) inevitable difficulties in application. Point (c) includes inadequacy not only in protective properties but, in the case of the hard-film materials, in certain physical properties, e.g. the film may become brittle and flake when handled, may remain too sticky and become contaminated with dirt or adhere to the... 

Where feed lines have short pipe runs, where hot wells or FW tanks are of small volume, or when FW is too cold, there often is insufficient time for full DO scavenging to take place, even when using catalyzed scavengers. The inevitable result of this lack of contact time is the formation of oxygen-induced corrosion products, which by various secondary mechanisms may settle out to form permanent deposits within the boiler system. These deposits may develop in several forms (e.g., where DO removal is particularly poor, they often appear as reddish tubercles of hematite covering sites where pitting corrosion is active). Active pitting corrosion combined with the presence of waterside deposits ultimately may lead to tube failure in a boiler or other item of system equipment and result in a system shutdown. 

Process contamination may, unfortunately, occur regularly in certain industries, and these process materials inevitably find their way into the FW system, and from there to the boiler, unless adequate precautions are taken. The result is severe fouling of the boiler, contamination of the steam generation process, and the potential for damage and boiler failure caused by overheating. 

Tube wall temperature is an important parameter in the design and operation of steam reformers. The tubes are exposed to an extreme thermal environment. Creep of the tube material is inevitable, leading to failure of the tubes, which is exacerbated if the tube temperature is not adequately controlled. The effects of tube temperature on the strength of a tube are considered by use of the Larson-Miller parameter, P (Ridler and Twigg, 1996) ... 

In spite of the frequency-shifted excitation, the quantized PIP inevitably excites multiple sidebands located at n/At ( = 1, 2,...) from the centre band. An attempt was made16 to calculate the excitation profile of multiple bands created by a PIP of a constant RF field strength, using an approximate method based on the Fourier analysis. The accuracy of the method relies partly on the linear response of the spin system, which is, unfortunately, not true in most cases except for a small angle excitation. In addition, the spins inside a magnet consitute a quantum system, which is sensitive not only to the strengths but also to the phases of the RF fields. Any classical description is doomed to failure if the quantum nature of the spin system emerges. 

CNTs have extremely high stiffness and strength, and are regarded as perfect reinforcing fibers for developing a new class of nanocomposites. The use of atomistic or molecular dynamics (MD) simulations is inevitable for the analysis of such nanomaterials in order to study the local load transfers, interface properties, or failure modes at the nanoscale. Meanwhile, continuum models based on micromechan-ics have been shown in several recent studies to be useful in the global analysis for characterizing such nanomaterials at the micro- or macro-scale. 

Once the plate starts to corrode, many problems appear to affect performance and durability, even serious failure, of fhe fuel cells. For example, fhe interface contact resistance between the corroded metal plates and GDL will increase to reduce the power output. The corrosion products (mainly various cations) will contaminate the catalyst and membrane and affect eir normal functions because the polymer membrane essentially is a strong cation exchanger and the catalyst is susceptible to the ion impurity. Hence, adding a corrosion-resistant coating to the metal plate will almost inevitably assure the performance and long-term durability of a sfack. 

The physical mechanism of membrane water balance and the formal structure of modeling approaches are straightforward. Under stationary operation, the inevitable electro-osmotic flux has to be compensated by a back flux of water from cathode to anode, driven by gradients in concentration, activity, or liquid pressure of water. The water distribution in PEMs that is generated in response to these driving forces decreases from cathode to anode. With increasing/o, the water distribution becomes more nonuniform. the water content near the anode falls below the percolation threshold of proton conduction, X < X. This leaves only a small conductivity due to surface transport of water. As a consequence, increases dramatically this can lead to failure of the complete cell. 

The modem Olympics were devised by men for men in 1896 anything else would have been quite shocking. Nevertheless a woman did, it is claimed, mn unofficially with the 25 male competitors in that first marathon. It was not until the Amsterdam Olympics of 1928 that three track events - the 100 m, 800 m and 4 x 100 m relay - were opened to women, together with the discus and high jump. Ai it turned out, this first women s Olympic 800 m event was to set back the course of women s athletics by many years since some of the participants in that race collapsed. Although the failures probably resulted from inadequate preparation (as they would have done for male athletes) they inevitably received more publicity than the winner, Lina Radke, from Germany. This provided support for the view that women should not be allowed to participate in such events. Indeed the 800 m event for women was not reinstated until the 1960 Olympic Games. 

Causal factor identification is relatively easy to learn and apply to simple incidents. For more complex incidents with complicated timelines, one or more causal factors can easily be overlooked, however, which inevitably will result in failure to identify their root causes. There are a number of tools, such as Barrier Analysis, Change Analysis, and Fault Tree Analysis, that can assist with bridging gaps in data and the identification of causal factors. Each of these tools has merits that can assist the investigator in understanding what happened and how it happened. 

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