Whole system design

For every Customer we know about businesswise, there is a Person in the System Design. We ve shown the relationship as the association abs. There are similar direct correspondences for several other types. In fact, the whole business model is implemented by the whole system design, so we ve shown that association, too. (The outer type boxes are shown in gray to reduce clutter in Figure 10.26. In real documentation, you d show them separately.) So we can say that... 

To be able to systematically identify opportunities for reducing human error, it is useful to ask the question, What is human error One definition is that human error is an inappropriate or undesirable human decision or behavior that reduces, or has the potential for reducing safety or system performance (Rasmusssen 1979). There is a tendency to view errors as operator errors. However, the error may result from inadequate management, design, or maintenance of the system. This broader view which encompasses the whole system can help provide opportunities for instituting measures to reduce the likelihood of errors. 

Transportation should be considered when assessing risks associated with planned or existing plants. The design of new chemical processing units should include at the earliest opportunity a qualitative or quantitative risk assessment of the whole system including production, use, and transportation in order to minimize overall risk. A brief discussion of the inherent safety aspects of transportation is included in Chapter 5. 

The whole system should be designed for ease of decontamination. The cupboard will incorporate a wash-down system. Adequate drainage in the cupboard and ductwork is required. Water drained from the system, including that from the fan casing, should be collected and properly disposed of. It should not be possible for water to get onto the work surface. 

Low-momentum air supply systems designed for local ventilation purposes mainly use vertically downward airflow. Some systems with an inlet of low-momentum horizontal airflow for a whole workroom are on the borderline between general and local ventilation and are therefore briefly described here. A more complete description will be found in chapters 7 and 8 dealing with general ventilation. 

In practical product design, a full LCA is seldom performed. The unit operations represent whole systems, which are used as building blocks. Typical examples include elementary flows determined for the manufacture of 1 m-1-mm sheet metal of galvanized steel, incineration of 1 kg of polyethylene, or production and distribution of 1 MJ electricity. ... 

System specification The engineering specification produced by the manufacturer of the equipment, or by the system designer for the plant as a whole, stating what the system is capable of achieving. 

Langley s aerodrome and the fate that befell it are an excellent study m the basic aspects of airplane design. Despite excellent propulsion and adequate aerodynamics, it was the poor structural design that resulted in failure of the whole system. 

LTHW systems are usually under a pressure of static head only, with an open expansion tank, in which case the design operating temperature should not exceed 83°C. Where MTHW systems operating above 110°C are pressurized by means of a head tank, an expansion vessel should be incorporated into the feed and expansion pipe. This vessel should be adequately sized to take the volume of expansion of the whole system so that boiling will not occur in the upper part of the feed pipe. On no account should an open vent be provided for this type of system. MTHW and HTHW systems require pressurization such that the saturation temperature at operating pressure at all points in the circuit exceeds the maximum system flow temperature required. A margin of 17 K (minimum)... 

Another important implication is that highly permeable soil liners generally have defects, such as cracks, macropores, voids, and zones, that have not been compacted properly. One opportunity to eliminate those defects is at the time of construction. Another opportunity arises after the landfill is in operation, and the weight of overlying solid waste or of a cover over the whole system further compresses the soil. This compression, however, occurs only on the bottom liners, as there is not much overburden stress on a final cover placed over a solid waste disposal unit. This is one reason why it is more difficult to design and implement a final cover with low hydraulic conductivity than it is for a bottom liner. Not only is there lower stress acting on a cover than on a liner, but also the cover is subjected to many environmental forces, whereas the liner is not. 

As in the business model, we can illustrate an effect of an action with a snapshot but in this case, the objects in the diagram denote not the real objects but rather the system s own representation of them (see Figure 1.19). For that reason, we draw the objects inside the system boundary, whereas the actions themselves are still actions on the whole system. This reflects the fact that we are not yet designing the internals of the system. 

On a larger scale, more-complex models can be used to represent the types of whole systems or components and are usually shown pictorially. In an abstract model, the attributes and their types are chosen to help specify the operations on the component as a whole and, according to good object-oriented analysis practice, are based on a model of the domain. However, anyone who has been involved in practical OOD is aware that the design phase introduces all sorts of extra classes as patterns are applied to help generalize the design, make it more efficient, distribute the design, provide persistence or a GUI, and so on. But we can still retrieve the abstract model from any tme implementation in the same way as for the simpler models. 

Further work is required for those components that are used in the design but not yet implemented—not purchased or adapted from previous projects. Just as we had a specification of the whole system and broke it into successive pieces, so each component can be broken into subcomponents, which in turn are specified and implemented until we get down to units directly implementable in program code. 

This is an abstract model of the state of the whole System, and says nothing about its construction — whether it is distributed or centralised, whether the links are database keys or pointers, whether the types can be found in the implementation as individual classes. These matters are all left to the design phase a distributed object implementation, or a server-based one with remote screen-control clients would both be equally valid choices. 

The isotope effect was first modeled using the ONIOM multi layer approach developed by Morokuma and coworkers (reading list). In this method a part of the whole system is selected for detailed quantum mechanical modeling and designated model while the whole system is called real . The total energy of (Eoniom) is given by Equation 11.87... 

In experiments at relaxation fields close to zero, the precision, resolution and stability of the absolute value of Br become critical and a bipolar configuration though it makes the design and implementation of the hardware more complex, it improves the precision of the whole system and offers the following advantages ... 

From the above it is obvious that a systems designer for laboratory automation must be conversant with and able to utilize a whole range of disciplines, from chemistry to electronics, and from computer software to statistics and instrument design. The users of the automation, their managers and the customer for the analytical results also have a contribution to make in deciding the spedflcation. 

The whole system, with its internal and external interfaces, is designed so that it can be adapted to the needs of any particular analytical wet-chemistry laboratory, and so that responsibility for the analysis can be assigned to the operator. The system can be arranged... 

The brand file and random smoking plans are central to the whole automation design philosophy. The brand file was the first segment of the system to undergo major revision when the data handhng moved from the bureau to the in-house computer. The information on the brand file not only enables an analyst to monitor certain administrative requirements on behalf of the customer, but also allows the file itself to accompHsh most of the control functions required by the data processing system. The software to drive this expanded brand file runs interactively from a terminal in the laboratory and gives the analyst the abihty to update and maintain the file, and exert a measure of control over the whole system. 

---