A semi-oriented radial measure for measuring the efficiency of decision making units with negative data, using DEA

Data Envelopment Analysis (DEA) is a nonparametric method for measuring the efficiency of a set of decision making units such as firms or public sector agencies, first introduced into the operational research and management science literature by Charnes, Cooper, and Rhodes (CCR) [Charnes, A., Cooper, W.W., Rhodes, E., 1978. Measuring the efficiency of decision making units. European Journal of Operational Research 2, 429–444]. The original DEA models were applicable only to technologies characterized by positive inputs/outputs. In subsequent literature there have been various approaches to enable DEA to deal with negative data. In this paper, we propose a semi-oriented radial measure, which permits the presence of variables which can take both negative and positive values. The model is applied to data on a notional effluent processing system to compare the results with those yielded by two alternative methods for dealing with negative data in DEA: The modified slacks-based model suggested by Sharp et al. [Sharp, J.A., Liu, W.B., Meng, W., 2006. A modified slacks-based measure model for data envelopment analysis with ‘natural’ negative outputs and inputs. Journal of Operational Research Society 57 (11) 1–6] and the range directional model developed by Portela et al. [Portela, M.C.A.S., Thanassoulis, E., Simpson, G., 2004. A directional distance approach to deal with negative data in DEA: An application to bank branches. Journal of Operational Research Society 55 (10) 1111–1121]. A further example explores the advantages of using the new model.

Analysis and optimisation of the performance of nonlinear optical communication systems

We investigate the feasibility of simultaneous suppressing of the amplification noise and nonlinearity, representing the most fundamental limiting factors in modern optical communication. To accomplish this task we developed a general design optimisation technique, based on concepts of noise and nonlinearity management. We demonstrate the immense efficiency of the novel approach by applying it to a design optimisation of transmission lines with periodic dispersion compensation using Raman and hybrid Raman-EDFA amplification. Moreover, we showed, using nonlinearity management considerations, that the optimal performance in high bit-rate dispersion managed fibre systems with hybrid amplification is achieved for a certain amplifier spacing – which is different from commonly known optimal noise performance corresponding to fully distributed amplification. Required for an accurate estimation of the bit error rate, the complete knowledge of signal statistics is crucial for modern transmission links with strong inherent nonlinearity. Therefore, we implemented the advanced multicanonical Monte Carlo (MMC) method, acknowledged for its efficiency in estimating distribution tails. We have accurately computed acknowledged for its efficiency in estimating distribution tails. We have accurately computed marginal probability density functions for soliton parameters, by numerical modelling of Fokker-Plank equation applying the MMC simulation technique. Moreover, applying a powerful MMC method we have studied the BER penalty caused by deviations from the optimal decision level in systems employing in-line 2R optical regeneration. We have demonstrated that in such systems the analytical linear approximation that makes a better fit in the central part of the regenerator nonlinear transfer function produces more accurate approximation of the BER and BER penalty. We present a statistical analysis of RZ-DPSK optical signal at direct detection receiver with Mach-Zehnder interferometer demodulation

The dynamics of organizational change : an analysis of power, professions and new managerialism in the case of CoastElectric

It is widely accepted that the Thatcher years and their immediate aftermath were associated with substantive social and organizational change. The privatisation programme, 'the rolling back of the State', prosecuted by the successive Conservative Governments from 1979-1997 was a central pillar of Governmental policy. This thesis seeks to engage with privatization through the of CoastElectric, a newly privatised Regional Electricity Company. This thesis contributes to the extant understanding of the dynamics of organizational change in four major ways. Firstly, the study into CoastElectric addresses the senior management decision making within the organization: in particular, it will attempt to make sense of 'why' particular decisions were made. The theoretical backdrop to this concern will draw on the concepts of normalization, cultural capital and corporate fashion. The argument presented in this thesis is that the decision-making broadly corresponded with that which could be considered to be at the vanguard of mangerialist thought. However, a detailed analysis suggested that at different junctures in CoastElectric's history there were differences in the approach to decision making that warranted further analysis. The most notable finding was that the relative levels of new managerialist cultural capital possessed by the decision-making elite had an important bearing upon whether the decision was formulated either endogenously or exogenously, with the assistance of cultural intermediaries such as management consultants. The thesis demonstrates the importance of the broader discourse of new managerialism in terms of shaping what is considered to be a 'commonsensical, rational' strategy. The second concern of this thesis is that of the process of organizational change. The study of CoastElectric attempts to provide a rich account of the dynamics of organizational change. This is realized through, first, examining the pre-existing context of the organization; second, through analyzing the power politics of change interventions. The master concepts utilised in this endeavour are that of: dividing practices, the establishment of violent hierarchies between competing discourses; symbolic violence; critical turning points; recursiveness; creative destruction; legitimation strategies and the reconstitution of subjects in the workplace.

A Generic model for the design and analysis of production systems

This dissertation studies the process of operations systems design within the context of the manufacturing organization. Using the DRAMA (Design Routine for Adopting Modular Assembly) model as developed by a team from the IDOM Research Unit at Aston University as a starting point, the research employed empirically based fieldwork and a survey to investigate the process of production systems design and implementation within four UK manufacturing industries: electronics assembly, electrical engineering, mechanical engineering and carpet manufacturing. The intention was to validate the basic DRAMA model as a framework for research enquiry within the electronics industry, where the initial IDOM work was conducted, and then to test its generic applicability, further developing the model where appropriate, within the other industries selected. The thesis contains a review of production systems design theory and practice prior to presenting thirteen industrial case studies of production systems design from the four industry sectors. The results and analysis of the postal survey into production systems design are then presented. The strategic decisions of manufacturing and their relationship to production systems design, and the detailed process of production systems design and operation are then discussed. These analyses are used to develop the generic model of production systems design entitled DRAMA II (Decision Rules for Analysing Manufacturing Activities). The model contains three main constituent parts: the basic DRAMA model, the extended DRAMA II model showing the imperatives and relationships within the design process, and a benchmark generic approach for the design and analysis of each component in the design process. DRAMA II is primarily intended for use by researchers as an analytical framework of enquiry, but is also seen as having application for manufacturing practitioners.

A longitudinal study of Chinese managerial behaviour:an inside view of decision-making under the economic reform

This research compared decision making processes in six Chinese state-owned enterprises during the period 1985 to 1988. The research objectives were: a) To examine changes in the managerial behaviour over a period of 1985 to 1988 with a focus on decision-making; b) Through this examination, to throw light on the means by which government policies on economic reform were implemented at the enterprise level; c) To illustrate problems encountered in the decentralization programme which was a major part of China's economic reform. The research was conducted by means of intensive interviews with more than eighty managers and a survey of documents relating to specific decisions. A total of sixty cases of decision-making were selected from five decision topics: purchasing of inputs, pricing of outputs, recruitment of labour, organizational change and innovation, which occurred in 1985 (or before) and in 1988/89. Data from the interviews were used to investigate environmental conditions, relations between the enterprise and its higher authority, interactions between management and the party system, the role of information, and effectiveness of regulations and government policies on enterprise management. The analysis of the data indicates that the decision processes in the different enterprises have some similarities in regard to actor involvement, the flow of decision activities, interactions with the authorities, information usage and the effect of regulations. Comparison of the same or similar decision contents over time indicates that the achievement of decentralization varied according to the topic of decision. Managerial authority was delegated to enterprises when the authorities relaxed their control over resource allocation. When acquisition of necessary resources is dependent upon the planning system or the decision matter is sensitive, because it involves change to the institutional framework (e.g. the Party), then a high degree of centralization was retained, resulting in a marginal change in managerial behaviour. The economic reform failed to increase decision efficiency and effectiveness of decision-making. The prevailing institutional frameworks were regarded as negative to the change. The research argues that the decision process is likely to be more contingent on the decision content than the organization. Three types of decision process have been conceptualized, each of them related to a certain type of decision content. This argument gives attention to the perspectives of institution and power in a way which facilitates an elaboration of organizational analysis. The problems encountered in the reform of China's industrial enterprises are identified and discussed. General recommendations for policies of further reform are offered, based on the analysis of decision process and managerial behaviour.

Decision making in nuclear waste management:the use of the synoptic approach

This thesis is concerned with the use of the synoptic approach within decision making concerning nuclear waste management. The synoptic approach to decision making refers to an approach to rational decision making that assumes as an ideal, comprehensiveness of information and analysis. Two case studies are examined in which a high degree of synoptic analysis has been used within the decision making process. The case studies examined are the Windscale Inquiry into the decision to build the THORP reprocessing plant and the Nirex safety assessment of nuclear waste disposal. The case studies are used to test Lindblom's hypothesis that a synoptic approach to decision making is not achievable. In the first case study Lindblom's hypothesis is tested through the evaluation of the decision to build the THORP plant, taken following the Windscale Inquiry. It is concluded that the incongruity of this decision supports Lindblom's hypothesis. However, it has been argued that the Inquiry should be seen as a legitimisation exercise for a decision that was effectively predetermined, rather than a rigorous synoptic analysis. Therefore, the Windscale Inquiry does not provide a robust test of the synoptic method. It was concluded that a methodology was required, that allowed robust conclusions to be drawn, despite the ambiguity of the role of the synoptic method in decision making. Thus, the methodology adopted for the second case study was modified. In this case study the synoptic method was evaluated directly. This was achieved through the analysis of the cogency of the Nirex safety assessment. It was concluded that the failure of Nirex to provide a cogent synoptic analysis supported Lindblom's criticism of the synoptic method. Moreover, it was found that the synoptic method failed in the way that Lindblom predicted that it would.

Computer aided design and analysis of cold formed sections

The work reported in this thesis is concerned with the improvement and expansion of the assistance given to the designer by the computer in the design of cold formed sections. The main contributions have been in four areas, which have consequently led to the fifth, the development of a methodology to optimise designs. This methodology can be considered an `Expert Design System' for cold formed sections. A different method of determining section properties of profiles was introduced, using the properties of line and circular elements. Graphics were introduced to show the outline of the profile on screen. The analysis of beam loading has been expanded to beam loading conditions where the number of supports, point loads, and uniform distributive loads can be specified by the designer. The profile can then be checked for suitability for the specified type of loading. Artificial Intelligence concepts have been introduced to give the designer decision support from the computer, in combination with the computer aided design facilities. The more complex decision support was adopted through the use of production rules. All the support was based on the British standards. A method has been introduced, by which the appropriate use of stiffeners can be determined and consequently designed by the designer. Finally, the methodology by which the designer is given assistance from the computer, without constraining the designer, was developed. This methodology gives advice to the designer on possible methods of improving the design, but allows the designer to reject that option, and analyse the profile accordingly. The methodology enables optimisation to be achieved by the designer, designing variety of profiles for a particular loading, and determining which one is best suited.

An evaluative analysis of the practice of teamwork in Health and Personal Social Services

This report describes the practice of teamwork as expressed in case conferences for care of the elderly and evaluates the effectiveness of case conferences in their contribution to care. The study involved the observation of more than two hundred case conferences in sixteen locations throughout the West Midlands, in which one thousand seven hundred and three participants were involved. Related investigation of service outcomes involved an additional ninety six patients who were interviewed in their homes. The pu`pose of the study was to determine whether the practice of teamwork and decision-making in case conferences is a productive and cost effective method of working. Preliminary exploration revealed the extent to which the team approach is part of the organisational culture and which, it is asserted, serves to perpetuate the mythical value of team working. The study has demonstrated an active subscription to the case conference approach, yet has revealed many weaknesses, not least of which is clear evidence that certain team members are inhibited in their contribution. Further, that the decisional process in case conferences has little consequence to care outcome. Where outcomes are examined there is evidence of service inadequacy. This work presents a challenge to professionals to confront their working practices with honesty and with vision, in the quest for the best and most cost effective service to patients.

Task classification and decision processes in monitoring behaviour

Task classification is introduced as a method for the evaluation of monitoring behaviour in different task situations. On the basis of an analysis of different monitoring tasks, a task classification system comprising four task 'dimensions' is proposed. The perceptual speed and flexibility of closure categories, which are identified with signal discrimination type, comprise the principal dimension in this taxonomy, the others being sense modality, the time course of events, and source complexity. It is also proposed that decision theory provides the most complete method for the analysis of performance in monitoring tasks. Several different aspects of decision theory in relation to monitoring behaviour are described. A method is also outlined whereby both accuracy and latency measures of performance may be analysed within the same decision theory framework. Eight experiments and an organizational study are reported. The results show that a distinction can be made between the perceptual efficiency (sensitivity) of a monitor and his criterial level of response, and that in most monitoring situations, there is no decrement in efficiency over the work period, but an increase in the strictness of the response criterion. The range of tasks exhibiting either or both of these performance trends can be specified within the task classification system. In particular, it is shown that a sensitivity decrement is only obtained for 'speed' tasks with a high stimulation rate. A distinctive feature of 'speed' tasks is that target detection requires the discrimination of a change in a stimulus relative to preceding stimuli, whereas in 'closure' tasks, the information required for the discrimination of targets is presented at the same point In time. In the final study, the specification of tasks yielding sensitivity decrements is shown to be consistent with a task classification analysis of the monitoring literature. It is also demonstrated that the signal type dimension has a major influence on the consistency of individual differences in performance in different tasks. The results provide an empirical validation for the 'speed' and 'closure' categories, and suggest that individual differences are not completely task specific but are dependent on the demands common to different tasks. Task classification is therefore shovn to enable improved generalizations to be made of the factors affecting 1) performance trends over time, and 2) the consistencv of performance in different tasks. A decision theory analysis of response latencies is shown to support the view that criterion shifts are obtained in some tasks, while sensitivity shifts are obtained in others. The results of a psychophysiological study also suggest that evoked potential latency measures may provide temporal correlates of criterion shifts in monitoring tasks. Among other results, the finding that the latencies of negative responses do not increase over time is taken to invalidate arousal-based theories of performance trends over a work period. An interpretation in terms of expectancy, however, provides a more reliable explanation of criterion shifts. Although the mechanisms underlying the sensitivity decrement are not completely clear, the results rule out 'unitary' theories such as observing response and coupling theory. It is suggested that an interpretation in terms of the memory data limitations on information processing provides the most parsimonious explanation of all the results in the literature relating to sensitivity decrement. Task classification therefore enables the refinement and selection of theories of monitoring behaviour in terms of their reliability in generalizing predictions to a wide range of tasks. It is thus concluded that task classification and decision theory provide a reliable basis for the assessment and analysis of monitoring behaviour in different task situations.

International business research and risky investments, an analysis of FDI in conflict zones

The purpose of this paper is to examine the determinants of a firm's strategy to invest in a conflict location. To the best of our knowledge, this has not been done before. We examine this using a standard model of international business, overlaid with the fundamental approach to corporate social responsibility. We start with the population of multinationals who have chosen to invest in low income countries with weak institutions. We then split this sample in order to distinguish between firms that have invested in conflict regions compared to those that have not. Our analysis then proceeds to explain the decision of those firms to invest in conflict locations using a simple Probit model. We find that countries with weaker institutions and less concern about corporate social responsibility (CSR) are more likely to invest in conflict regions. Finally, firms with more concentrated ownership are more likely to invest in such locations. © 2012 Elsevier Ltd.

Minimizing nasty surprises with better informed decision-making in self-adaptive systems

Designers of self-adaptive systems often formulate adaptive design decisions, making unrealistic or myopic assumptions about the system's requirements and environment. The decisions taken during this formulation are crucial for satisfying requirements. In environments which are characterized by uncertainty and dynamism, deviation from these assumptions is the norm and may trigger 'surprises'. Our method allows designers to make explicit links between the possible emergence of surprises, risks and design trade-offs. The method can be used to explore the design decisions for self-adaptive systems and choose among decisions that better fulfil (or rather partially fulfil) non-functional requirements and address their trade-offs. The analysis can also provide designers with valuable input for refining the adaptation decisions to balance, for example, resilience (i.e. Satisfiability of non-functional requirements and their trade-offs) and stability (i.e. Minimizing the frequency of adaptation). The objective is to provide designers of self adaptive systems with a basis for multi-dimensional what-if analysis to revise and improve the understanding of the environment and its effect on non-functional requirements and thereafter decision-making. We have applied the method to a wireless sensor network for flood prediction. The application shows that the method gives rise to questions that were not explicitly asked before at design-time and assists designers in the process of risk-aware, what-if and trade-off analysis.

A method for systematic artifact selection decision making

Artifact selection decisions typically involve the selection of one from a number of possible/candidate options (decision alternatives). In order to support such decisions, it is important to identify and recognize relevant key issues of problem solving and decision making (Albers, 1996; Harris, 1998a, 1998b; Jacobs & Holten, 1995; Loch & Conger, 1996; Rumble, 1991; Sauter, 1999; Simon, 1986). Sauter classifies four problem solving/decision making styles: (1) left-brain style, (2) right-brain style, (3) accommodating, and (4) integrated (Sauter, 1999). The left-brain style employs analytical and quantitative techniques and relies on rational and logical reasoning. In an effort to achieve predictability and minimize uncertainty, problems are explicitly defined, solution methods are determined, orderly information searches are conducted, and analysis is increasingly refined. Left-brain style decision making works best when it is possible to predict/control, measure, and quantify all relevant variables, and when information is complete. In direct contrast, right-brain style decision making is based on intuitive techniques—it places more emphasis on feelings than facts. Accommodating decision makers use their non-dominant style when they realize that it will work best in a given situation. Lastly, integrated style decision makers are able to combine the left- and right-brain styles—they use analytical processes to filter information and intuition to contend with uncertainty and complexity.

Investing in conflict zones:a firm-level analysis

The purpose of this paper is to examine, using panel data econometric techniques, the determinants of a firm’s strategy to invest in a conflict location. To the best of our knowledge this has not been done before. We use a large database of firm-level data that includes 2858 multinational firms that have a subsidiary in a developing country (during 1999-2006). Out of these firms 290 are classified as having a subsidiary in a conflict location. The choice of a conflict location is based on data from the Inter Country Risk Guide (ICRG). We start with the population of multinationals who have chosen to invest in low income countries with weak institutions. Our analysis then proceeds to explain the decision of those firms to invest in conflict locations. We have four hypotheses: (1) Firms with concentrated ownership are more likely to invest in a conflict region; (2) Firms from countries with weaker institutions are more likely to invest in conflict regions; (3) Firms and Countries with less concern over corporate social responsibility are more likely to invest in conflict countries; and (4) that there is large sector level differences in the propensity to invest in a conflict region. The results suggest that all of these hypotheses can be confirmed.

Fuzzy data envelopment analysis:a discrete approach

Data envelopment analysis (DEA) as introduced by Charnes, Cooper, and Rhodes (1978) is a linear programming technique that has widely been used to evaluate the relative efficiency of a set of homogenous decision making units (DMUs). In many real applications, the input-output variables cannot be precisely measured. This is particularly important in assessing efficiency of DMUs using DEA, since the efficiency score of inefficient DMUs are very sensitive to possible data errors. Hence, several approaches have been proposed to deal with imprecise data. Perhaps the most popular fuzzy DEA model is based on a-cut. One drawback of the a-cut approach is that it cannot include all information about uncertainty. This paper aims to introduce an alternative linear programming model that can include some uncertainty information from the intervals within the a-cut approach. We introduce the concept of "local a-level" to develop a multi-objective linear programming to measure the efficiency of DMUs under uncertainty. An example is given to illustrate the use of this method.

Improving envelopment in Data Envelopment Analysis under variable returns to scale

In a Data Envelopment Analysis model, some of the weights used to compute the efficiency of a unit can have zero or negligible value despite of the importance of the corresponding input or output. This paper offers an approach to preventing inputs and outputs from being ignored in the DEA assessment under the multiple input and output VRS environment, building on an approach introduced in Allen and Thanassoulis (2004) for single input multiple output CRS cases. The proposed method is based on the idea of introducing unobserved DMUs created by adjusting input and output levels of certain observed relatively efficient DMUs, in a manner which reflects a combination of technical information and the decision maker's value judgements. In contrast to many alternative techniques used to constrain weights and/or improve envelopment in DEA, this approach allows one to impose local information on production trade-offs, which are in line with the general VRS technology. The suggested procedure is illustrated using real data. © 2011 Elsevier B.V. All rights reserved.