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Table 4.5 Process capacities per subgroup. Sub-system group No. Each state in the simple power plant example has only one subgroup that is the limiting factor, or bottleneck, for the plant’s power output capability in that state.. The single A subgroup (consisting of two coal bin sub-systems) is wide enough to handle 100% of the flow;. Each of the two...
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Complicatedness is the degree to which any control over the system is able to manage the level of complexity presented by the system. The means of control can be another system or a person. Inevitably, there is a level of complex- ity at which any means of system control simply cannot cope with the system as a whole. The system...
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4.45 Dynamic systems simulation in the blackboard model. To take full advantage of virtual prototyping, it is necessary to develop a mod- elling paradigm that supports model reuse, that is integrated with the design environ- ment, and that provides a simple and intuitive user interface that requires a minimum of analysis expertise, as shown in Fig. General configuration of process...
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4.4 Application Modelling of Availability and Maintainability in Engineering Design 503. Table 4.14 Preliminary design data for simulation model sector 1. Storage bin 1 U . Storage bin 2 U . Storage bin 3 U . a) Evaluation of Simulation Model Sector 1. A major characteristic of the process flow diagram (PFD) of sector 1 is that it depicts material...
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Table 4.18 Comparative analysis of preliminary design data and simulation output data for simu- lation model sector 2. e) Evaluation of Simulation Model Sector 3. A major characteristic of the process flow diagram (PFD) of sector 3 is that it depicts continuous fluid flow and indicates how inputs are transformed by each assembly into outputs that, in turn, become modified...
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Consider the application and significance of systems engineering in engineering design.. Briefly discuss complexity in engineering design and its significance in systems engineering.. Give a brief account of the functions of systems engineering analysis.. Consider effectiveness measures in systems engineering and their significance in engineering design.. Give a brief account of evaluating complexity in engineering design.. Describe various system state...
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534 5 Safety and Risk in Engineering Design whom died within weeks from radiation exposure. It is estimated that at least 5% of the total radioactive material in the Chernobyl-4 reactor core was released from the plant, due to the lack of any containment structure. About 800 cases of thyroid cancer in children have been linked to the accident. An...
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Fault tree. Fault tree Yes. 1999) have emerged to reconcile deficiencies in the tree-based analysis techniques.. DA is an extension of the technique to system control hardware. Deviation analysis determines whether hazardous systems behaviour can result from a class of input deviations inclusive in the broad range of process characteristics such as ca- pacity, input, throughput, output and quality. Hazardous...
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In the following Figs. 5.6 and 5.7, a graphic example is given of a potential outage in a power generation unit due to root cause failure in the boiler feed water pump, expanded to the potential root cause areas of equipment design, manufacture and maintenance. Figure 5.8 gives a layout of the factor tree for the origin of design criteria.....
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For each sequence of the event tree, the fault trees of the composing events are linked in one large fault tree that follows the logic depicted in the event tree, and the fault tree is then solved with the usual techniques to compute the probability of occurrence of that sequence.. If the probability of the sequence ( I. S 2...
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The cause-consequence diagram is reduced to a minimal form by, firstly, remov- ing any redundant decision boxes and, secondly, manipulating any common failure events that exist on the same path. An algorithm has been developed that will produce the correct cause-consequence diagram and calculate the exact system failure probability for static systems with binary success or failure responses to the...
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the ‘estimated reportable hazard frequency’ arising from functional failure of the item,. the ‘estimated physical condition’ of the item related to its safety.. This is measured according to the contribution of:. the ‘actual disabling injury frequency’ arising from functional failure of the item,. the ‘actual reportable hazard frequency’ arising from functional failure of the item,. the ‘actual physical condition’ of...
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The cost of ensuring the required reliability and safety relative to the selected at- tributes can be formulated as. C f = cost of failure relative to the selected attributes R = risk of a failure incident occurring.. p = the probability of the event occurring c = the consequence of the risk on the estimate.. As a result, it...
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Furthermore, it is always advisable to take into account the level of training and experience of the personnel who will be operating the plant. However, systems modelling approaches have to be adapted to the information that is available at certain points in the design stage.. Thus, the initial model, derived in the early design phases, must be refined by adding...
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e) Critical Risk Theory in Designing for Safety. z k , all of which must function for the system to be able to function, and where the useful life length of the system is Z.. Denoting the survival function of the useful life expectancy of Z by F , and of z i by F i ( i . The...
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3.3.3.4 and illustrated in Fig. The problem with the model, though, is the lack of any detailed data for generic sys- tems, assemblies and components, to provide an adequate assessment of safety in engineering design—especially in the preliminary design phase. A somewhat different approach to the beta factor model has thus been taken in which the beta values are not...
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is obtained by multiplying the p.g.f.s of the random variables together. 5.2.4.2 Cause-Consequence Analysis for Safety Systems Design. Cause-consequence analysis for safety systems design is fundamentally a combina- torial symbolic logic technique, utilising the symbolic logic of fault-tree analysis (FTA), reliability block diagramming (RBD) and event tree analysis (ETA). Fault trees are generated in the failure domain, reliability diagrams are...
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interval Main PCV V1 Stop high-pressure. Sub-PCV V2 Stop high-pressure surge passing through system. ESD valve V3 Stop high-pressure surge passing through system. HIPS1 V4 Stop high-pressure surge passing through system. HIPS2 V5 Stop high-pressure surge passing through system. Pressure sensors. Pr S Indicate the level of pressure to the computer. a high-pressure surge originating from process circulation pumps, to...
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to the point of impracticality where, for example, consideration is given only to sin- gle modes of failure, or only to random failure occurrences, or to maintenance that results in complete renewal and ‘as new’ conditions. At best, the intrin- sic failure characteristics of components of equipment are determined from quan- titative probability distributions of failure data obtained in a...
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Table 5.18 (continued) Component Failure. TLF Low pressure switch fails due to corrosion or mechanical damage. 2 T heoret ical Ov ervi ew of Safet y and R is k in E ngi neeri ng D esi gn 665 Table 5.19 FMECA for process and cost criticality. Fails to open TLF Production Medium. 666 5 Safety and Risk in Engineering...