Abstracting the logical processing life cycle for entities using the RECAST method

The case study described in this chapter concerns the introduction of a new computer based integrated Clinical Information System (CIS) into a British National Health Services Trust-the Sunrise Trust. At the time of the study most of the system modules had been developed and were being tested largely for technical aspects. The system was being introduced during a period when the organization was experiencing significant changes. It was an environment where new structures were being created and the existing ones changed. Indeed, the case study was selected primarily because of these factors. The analysis of these structures, formal and informal, provides insight into the management of information systems. Various stakeholders in the Hospital Trust felt that a computer based information system would facilitate the change process. However the analysis and design of the system posed its own problems. The system turned out to be inflexible with respect to the core health care delivery process. It was also nonresponsive to the needs of the key stakeholders. Analysis of the case shows that clearly the formal methods adopted by the system analysts fell short of determining the rapid changes required for care. In particular this was an important issue, since the context of the British National Health Services posed pressures on individual trusts to be cost effective. This resulted in long term patients being moved out into the community. However, this richness in the context was overlooked by the analysts. They developed “logical” models of the system, which ended up in being “tidy pictures of reality” and were prescriptive and utterly inflexible. Structured Systems Analysis and Design Method (SSADM) was used as a modelling tool, which amplified the rational view of decision making and information technology (IT) applications (for more details on SSADM see Downs et al., 1988). The interpretations identified in the case show a clear mis-match between the formal models and perceptions of the system users who inevitably reflect a more informal and pragmatic approach to their own organizational realities. The analysis of the case poses a number of interesting issues. It questions the relationship between the complexity of the social relations and systems design. Furthermore it brings to the fore the paradoxical viewpoints of different stakeholders and the emergent concerns for a system analyst. The chapter also identifies the impact of an “overformalized” information system on the integrity of an organization. In doing so it evaluates the nature and significance of social power structures in systems analysis, design and implementation.

I worked for a British computer company in the 1990s, and it was company policy to use SSADM (Structured Systems Analysis and Design Method) for any new projects. At the time, we were working on a part of the London Underground (also called the Tube) automation. I went to my manager with the time estimate for a new module that I was designing. The estimate was high, and he asked, “What are all these tasks for gathering requirement specifications and technical system options?” I said those were SSADM-based tasks. He replied: “We can do the documentation later. Right now, get on with the database design and front-end development.” A lot of years later, that attitude has not gone away.

The Structured Systems Analysis and Design Method (SSADM) is the standard method for systems analysis and design in Government batch and transaction processing projects. In SSADM, analysis and design are clearly separated activities. Systems analysis is concerned with defining what has to be done, systems design with how it will be done.

Integrating human factors with the Jackson System Development method: an illustrated overview.

We explain the main ingredients of the Abstract State Machines (ASM) method for high-level system design and analysis and survey some of its application highlights in industrial software-based system engineering. We illustrate the method by defining models for three simple control systems (sluice gate, traffic light, package router) and by characterising Event-B machines as a specific class of ASMs.We point to directions for future research and applications of the method in other areas than software engineering.

This thesis presents a new modelling method for information systems analysis and design, where the concept of service and the principles of service orientation are used for integrated modelling and reasoning about information systems architectures across organisational and technical systems boundaries. The concept of service enables cohesion of the intersubjective and objective modelling traditions by using a single type of diagram that facilitates detection of semantic inconsistency, incompleteness, ambiguity and discontinuity between the static and dynamic aspects of information systems specifications. The thesis is focused on three research topics, which are fundamental to the development of a new service-oriented modelling method. The first research topic concerns a pragmatic-driven specification of information systems. It clarifies answers to the research question: How can a conceptual modelling process be driven by pragmatic considerations? The second research topic provides a service-oriented modelling foundation for information systems analysis and design. It answers the research questions: How can the concept of service be used explicitly for the analysis and design of information systems and how can the static and dynamic aspects of information systems specifications be integrated at the conceptual level? The third research topic presents transition principles to implementation-specific design and answers the research question: How can service-oriented conceptual representations be aligned with implementation-specific design? The thesis contributes with a new knowledge to the area of conceptual modelling of information systems. The service-oriented modelling method consists of the modelling process, modelling language and techniques for the analysis and design of information systems on three levels of abstraction: pragmatic, semantic and syntactic. These three levels are necessary for a holistic understanding of enterprise architecture by stakeholders. The advantage of the service-oriented modelling method is that it can help to control traceability from information system design to original requirements. The method facilitates the semantic integration of the structural, behavioural and interactive aspects of information systems conceptual representations by using a single diagram type. The modelling language provides service-oriented constructs that are fundamental to building the major systems analysis patterns. The service-oriented modelling process contributes with seven steps of incremental design, which justifies various information systems components. The method provides the basis for a gradual and systematic way of modelling and an understanding of how pragmatic, semantic and logical information system requirements are linked together. The possibility to detect and eliminate undesirable characteristics of service-oriented diagrams can help to improve communication among stakeholders. Service-oriented specifications are computation-neutral and therefore they are more comprehensible for business analysis experts in comparison to implementation specific graphical representations of information systems. Finally, this thesis presents the challenges for future research, one of which is the development of the automated tools for the alignment of business models with implementation-specific information systems specifications.

Background: Piezoceramic materials have unique property which enables direct and bilateral conversion between mechanical and electrical energy. This ability facilitates significant miniaturisation of technology and opens many opportunities in design of new actuators and energy harvesters. Mathematical modelling of piezoelectric modules is notoriously hard due to complex constitutive equations defining mechanical and electrical energy conversion. Methods: The article presents research on a new synthesis method based on the Cauer’s method for electrical and mechanical system design. Mechanical damping is introduced with the use of Rayleigh’s approximation. A discrete electromechanical model is formed based on the Mason’s piezoelectric model. As an additional element of the research, a non-standard model analysis method using edge graphs and structural numbers is employed to investigate potential reductions in computational requirements for model analysis. Results: The electromechanical model analysis has shown an error of 5% in relation to the resonance target. The calculated peak in magnitude of displacement at the resonant frequency was well above the capability of a 3.5mm thick piezoelectric plate. The proposed non-standard method of analysis gave identical results in terms of obtained resonance frequencies. The calculated magnitude of vibrations was varying by 50 – 58%. Conclusions: The synthesis method presented in this paper allows an approximation of piezoelectric parameters of a real system based on the created mathematical model. Currently this method is subject to a considerable error in the determined vibration amplitudes of the system, but it allows a coarse approximation of the parameters while having a very limited number of input data. The additional method of analysis based on structural numbers offers a promising alternative to matrix calculations but requires a more thorough investigation of the computational power required to determine whether it can compete with existing algorithms.

A systematic frequency domain method for nonlinear analysis, design and estimation of nonlinear systems is established based on the discussions in the previous chapters. Firstly, this method allows accurate determination of the linear and nonlinear components in system output spectrum of a given nonlinear system described by NDE, NARX or NBO (nonlinear block-oriented) models, with some simulation or experiment data. These output spectrum components can then be used for system identification or nonlinear analysis for different purposes such as fault detection etc. Secondly, the OFRF discussed before is expressed into a much improved polynomial function, referred to here as nonlinear characteristic output spectrum (nCOS) function, which is an explicit expression for the relationship between nonlinear output spectrum and system characteristic parameters of interest including nonlinear parameters, frequency variable, and input excitation magnitude (not just nonlinear parameters as that in Chaps. 7 and 8 ) with a more generic parametric structure. With the accurate determination of system output spectrum components in the previous step, the nCOS function can therefore be accurately determined up to any high orders, with less simulation trials and computation cost compared with a pure simulation based study or traditional theoretical computation. These results can provide a useful approach for qualitative and quantitative analysis and design of nonlinear dynamics in the frequency domain.

Systematic design methods are widely diffused in academia, representing a standard in many engineering courses. Nevertheless, some flaws related to the conceptual design phase have been ascribed to these methods, especially concerning a non-comprehensive support to innovation. However, literature acknowledges several creativity-enhancing tools that can be conveniently combined with systematic design methods. In particular, many scholars refer to TRIZ, i.e. the well-known Russian problem-solving theory. Moreover, recent literature contributions propose some alternatives to the classical Functional Decomposition and Morphology (FDM), claiming to overcome some of the related flaws. One of them is the Problem Solution Network (PSN) approach, i.e. a systematic conceptual design method strongly based on a problem-solution co-evolutionary logic. In this context, our work aims at combining the potentialities of TRIZ with the benefits claimed for the PSN, by proposing a comprehensive integration procedure. Accordingly, this paper reports a detailed description of the proposal, where TRIZ tools are exploited to support problem solving within the PSN approach. Furthermore, an application is also reported where an industrial case study is presented to argue about possible potentialities and lacks of the proposed approach.

ABSTRACTIn this work a probabilistic structural analysis of a container terminal wharf is presented. Through the application of the Monte Carlo Simulations in a finite element structural model, the statistics of the axial forces at the pile heads were evaluated. Considering only ship berthing conditions, but varying equipment type, number and positions, ten external load combinations were analyzed and compared. Both finite element model and probabilistic analysis were performed in ANSYS software, v.16, on its APDL Mechanical and Probabilistic Design System packages respectively. The random input parameters considered were the concrete structure, pavement and rear landfill self-weight, live loads and ship sizes, for which statistical parameters were attributed based on bibliography or data collection. PIANC’s berthing energy method for fender systems design was applied for the evaluation of ship berthing forces acting on the structure. Considering the axial forces as the main parameters in the design of partially embedded piles, the random output parameters obtained were the minimum and maximum axial forces on each simulation. That approach, applied due to the possibility of ANSYS to be programmed through its Parametric Design Language (APDL), proved to be a powerful tool for probabilistic analysis of complex structural systems. The results present a comparison between the statistical parameters and probability density curves for the ten cases analyzed, by which the worst combinations from a probabilistic point of view could be defined. Keywords: Container terminal berth; Probabilistic Analisys; Monte Carlo Method; Finite Element Method; ANSYS.

Although many information systems (IS) design methods and techniques are available to IS professionals, none of them completely supports the design process. One of the problems is that there is a mismatch between IS design method; and the system to be built. Actually, in designing an IS, the methods or techniques employed should match the types and characteristics of the system to be built. Thus paper will explore the relationship between IS types/characteristics and systems design methods, and provide IS designers with a systems framework to develop methods or techniques that match the types and characteristics of IS.

Vehicle suspension (or vibration control) systems are usually inherently nonlinear and can be modeled as single input multiple output (SIMO) system. In this paper, parametric convergence bounds for Volterra series expansion of nonlinear systems described by a SIMO nonlinear auto-regressive with exogenous inputs model are studied in the frequency domain, which can clearly indicate the parametric range in which a given nonlinear system has a convergent Volterra series expansion, referred to as parametric bound of convergence (PBoC). With the resulting PBoC of characteristic parameters, nonlinear systems with a nonlinear multiobjective performance (MOP) function can then be analyzed in the frequency domain using a nonlinear characteristic output spectrum method based on the Volterra series expansion. To demonstrate the results and method above, a vehicle suspension system, which is taken as a typical SIMO nonlinear system with a MOP function to optimize, is investigated. The results demonstrate a systematic and novel method for nonlinear analysis and design.

Translational rate command (TRC) in helicopter flight involves controlling the earth-referenced forward and side velocities, using the helicopter’s cyclic control. Handling qualities requirements for TRC systems suggest that the design should comprise an inner attitude command-attitude hold (ACAH) loop, with TRC control as an outer loop. This forms a non-square system, and a method to determine the implications of this structure for stability robustness is proposed here. Control synthesis was performed using the method of individual channel analysis and design . This technique is a neo-classical, frequency-domain control analysis and design method for multivariable systems. The control law obtained is very simple, and the handling qualities, assessed by non-linear simulation, are predicted to be at ‘Level 1’ (satisfactory without improvement). The conditions for stability robustness are satisfied at frequencies of significance for the handling qualities.

The paper presents a method of engineering analysis and design for complex control systems, the time-domain infinite-matrix method. The formulation of the infinite matrix follows from the convolution summation of sampled-data systems. The mathematical basis of the time-domain matrix formulation is related to the applicable concepts of infinite matrices and sequence spaces. The method is applicable to both continuous-data and sampled-data systems. For continuous systems it is necessary to introduce a fictitious sampler and `hold? of sufficient sampling rate to effect an accurate approximation. The time-domain-matrix method is presented and illustrated as a method of analysis and design of linear, non-linear, and time-varying systems of the continuous-data or sampled-data class. The investigation of non-linear systems is greatly simplified by the time-domain approach. Multi-loop systems may be investigated, and the signals at intermediate points throughout the loops are readily available. Also, systems with multiple non-linearities may be investigated. Two methods of design of a discrete compensator for a sampled-data system are presented. These methods are accomplished directly in the time domain and allow for a compromise of specifications in the time domain. In one design procedure the response between sampling instants is also accounted for. The time-domain-matrix method may be readily programmed on a digital computer, and therefore provides a rapid analysis and design technique.

Recent theoretical developments have improved the understanding of gain scheduled control and suggested new methods for design, analysis and implementation of such nonlinear control systems. An integrated software environment for gain scheduled local controller network design and analysis, including computer-aided modelling and system identification, is described. Some background theory is included, and a speed control design problem for an experimental vehicle illustrates the application of the approach.