2.5 A model of systems modelling Much, if not most quantitative modelling is carried out in the context of engineering, business and financial studies. These uses of quantitative models are usually not part of a systems approach. Furthermore much of the modelling carried out in systems studies is not quantitative, since issues can often be resolved by using diagrammatic or conceptual models. It is therefore important to clarify the systems context in which modelling in general, and quantitative modelling in particular, will
5.2 The aims and principles of system engineering The aims of systems engineering can be divided into those to do with its outputs and those associated with the process itself. As far as its outputs are concerned, systems engineering aims to ensure that: the requirements of all the stakeholders are taken into account in engineering the system the system, as engineered and realised, meets the requirements of stakeholders the system, while meeting the req
Stage 7: Implement changes Finally, the agreed changes are implemented. Like the hard systems approach, soft systems methodology is not seen as a ‘one pass’ procedure, but as a learning process. Iteration is a feature of the methodology's application. Learning is achieved in both approaches by the use of models, although soft systems has subsequently been enhanced to include a specific analysis of the culture and politics of the problem situation, as shown in Author(s):
Stage 5: Comparison of Stages 2 and 4 The objective of the comparison stage is to relate the conceptual model to the problem situation as depicted in the rich picture. The idea is to highlight differences between the two so that potential improvements to the problem situation can be identified.
Stage 3: Relevant systems and root definitions The issues and key tasks extracted from the rich picture become the basis for defining what are called the ‘relevant systems’. For example, suppose the problem situation is a deteriorating performance in a call centre. One of the issues might be the (high) turnover of call centre operators. This might lead (depending on the point of view taken) to an idea of the call centre as an ‘employment-providing system’ or an ‘entertainment system’. There is no reason to restrict relevant sy
4.4 Fibre in the access network In the 1980s there was a belief that it was only a matter of time before fibre would be installed in the access network (from individual private customers to the local telephone exchange, also called ‘the last mile’, the ‘local loop’ and, now, the ‘first mile’). Installing ‘fibre to the home’, FTTH, as this has come to be known, was always recognised to be a major undertaking, simply because of the number of links involved. If, however, the revenue from new services enabled by
Activity answers
Study Note: As outlined in the text I have not provided answers to all Activities. This is for two reasons:
For some activities only you can devise the answer and any I gave would be distracting or unhelpful.
For others in-text answers are given.
6.8 Anticipating the arguments 18. Have the objectives and perspectives of all the key stakeholders concerned with the decision been taken account of in the previous assessment of costs, benefits and risks? 19. What are the reasons that this proposal is preferred over other op 3.3 Business operations: a transformation process The view that operations is the set of processes responsible for producing the organisation's intended outputs from an appropriate range of resource inputs can be represented very simply, as in Figure 2. 7.3.4 Physical vapour deposition (PVD), sputtering An ion hitting a metal surface after acceleration through more than 100 V will not stick or bounce off but will burrow into the surface, splashing atoms outwards. This is known as sputtering and provides a versatile alternative to thermal evaporation for metal-vapour deposition: more controllable, with adjustable uniformity, able to cope with alloys and high-melting-point metals and suitable for production-line automation. Given these advantages, it is also worth the effort to heat the Learning outcomes After you have completed this unit you should be able to demonstrate that you have achieved the following learning outcomes: an understanding of how to relate physical dimensions and materials properties to static and dynamic behaviour; an awareness of how small features are cut out in solid materials, and how small features are built up in solid materials; describe the piezoelectric effect and its use for producing small-scale movement in mechanica 3.1.4 The CCD in practice
Figure 8 shows a block diagram of the essential features of a CCD camera's image capture ‘from light to bits’. The full camera includes memory, power supplies, lens and subsystems control, digital and human interfaces, etc. 7.2 The professional engineer It has been suggested that there are four main criteria that identify a profession: Custody of a clearly definable and valuable body of knowledge and understanding associated with a long period of training. A strong unitary organization which ensures that the profession generally speaks with ‘one voice’. Clearly defined and rigorous entry standards, backed up by a requirement to register with the profes 4.5.2 Physical models A physical model of an artefact or component is often built on a reduced scale, in size and/or by using materials that are cheaper and easier to manipulate than those intended for production. At this stage, we are not necessarily producing what you might think of as a prototype, but investigating particular aspects of the design. For instance, maybe we would produce a racing-bike frame to a new design but in a cheap material such as balsawood, in order to assess the air flow around it in a wi 5.10 Bridge stability Any fracture of the diagonal wind brace tie bars could allow substantial lateral movement at the top of the piers. If these tie bars had already been injured by the previous train to cross the bridge, it would have only taken a little extra effort to complete the process as the mail train arrived over each pier supporting the high girders. Once the wind braces had failed completely, and the struts fractured at their connections each pier would behave as two separate supporting structures. Introduction This unit starts by giving an overview of the two main categories of disasters: disasters of natural origin and disasters of human origin. It then analyses the Tay Bridge disaster, which was caused by mechanical failure. Inevitably, human factors emerge as important in many major disasters. They may involve the failure by engineers, designers or managers to recognise faults in safety-critical products, or managers overriding the design team for other reasons – such as keeping to a dea Introduction This unit examines how self-assembled structures based on lipids and proteins provide a framework for cellular processes. This unit is an adapted extract from the Open University course Engineering small worlds: micro and nano technologies
(T356). 8.3 Summary A fundamental musical and acoustical relationship is the octave. Pitches that are one or more octaves apart are heard musically as different instances of the same sound. A one-octave increase in pitch corresponds to a doubling of frequency. For musical purposes, a pitch range of one octave is divided into discrete steps, known as scales, the individual pitches of which are given letter names (A, A 7.2 Summary Pitch and loudness are subjective properties of sound. Pitch is closely correlated with frequency, and loudness is closely correlated with amplitude. However, under certain circumstances, slight changes of pitch can be created by changes of amplitude, and changes of loudness can be created by changes of frequency. The ear's uneven response is part of the explanation for these latter phenomena. In the pitch standard known as concert pitch, the note A4 (the A above middle C) is set t 6.2 Practical units of amplitude The amplitude of a sine wave is measured in whatever units are used to calibrate the vertical axis, as you saw in connection with Figures 18 and Author(s):
Author(s):
