853 resultados para Probabilistic decision process model
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This paper takes a practice perspective on organizing, re-conceptualizing coordination mechanisms as dynamic activities that are under continuous construction and modification in order to socially accomplish intra-organizational relationships and activities. The paper is based on the case of Servico, an organization undergoing a major reorganization of its value chain in response to a change in government regulation. We examine the specific performances through which the ostensive and abstract character of a coordination mechanism, ‘end-to-end management’, is defined and refined into a set of activities that actors can use to effect the re-organization of relationships between two divisions during the delivery of a critical regulatory goal. We find six cycles of iteration between the ostensive and performative nature of end-to-end, which progressively help to organize three phases in the reorganization of Servico; absence, presence and formalization. The discussion examines the processual evolution of these cycles and phases and their implications for the way that reorganization occurred. We draw these findings together in a process model that makes contributions to the literature on organizing, on ostensive and performative routines, and on organizational restructuring.
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This paper presents the results of a multinational large-scale survey, investigating the current trends in strategic planning. The survey was conducted online using the Warwick Business School alumni database. Considering the development and implementation of strategy within a multi-process framework, the 'Strategic Development Process' model by Dyson and O'Brien (1998), using factor analysis, four distinct factors of strategic planning have been produced and with regression analysis, their impact on the success of strategic planning from a process point of view has been assessed. The results indicate that significant variation in practices involved is created by complexity either of the organizational size or environmental turbulence.
Resumo:
This paper takes a practice perspective on organizing, re-conceptualizing coordination mechanisms as dynamic activities that are under continuous construction and modification in order to socially accomplish intra-organizational relationships and activities. The paper is based on the case of Servico, an organization undergoing a major reorganization of its value chain in response to a change in government regulation. We examine the specific performances through which the ostensive and abstract character of a coordination mechanism, ‘end-to-end management’, is defined and refined into a set of activities that actors can use to effect the re-organization of relationships between two divisions during the delivery of a critical regulatory goal. We find six cycles of iteration between the ostensive and performative nature of end-to-end, which progressively help to organize three phases in the reorganization of Servico; absence, presence and formalization. The discussion examines the processual evolution of these cycles and phases and their implications for the way that reorganization occurred. We draw these findings together in a process model that makes contributions to the literature on organizing, on ostensive and performative routines, and on organizational restructuring.
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In global environment, a company has to make many decisions that impact upon its position in global supply chain networks such as outsourcing, offshoring, joint venture, vertical/horizontal integration, etc. All these decisions impact on the company’s strategic position, and hence on competitive space and performance. Therefore, it is important for a company to carefully manage strategic positioning by making careful decisions about the adoption of alternative manufacturing and supply chain activities. Unfortunately, there is no complete process studied in strategic positioning of manufacturing operations within global supply chain. Therefore, the work presented in this paper has investigated leading research and industrial practices to create a formal and rational decision process. An analysis of previous literature, industrial practices, and the resulting decision process are all presented in this paper.
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Purpose – The purpose of this paper is to report on an investigation into the selection and evaluation of a suitable strategic positioning methodology for SMEs in Singapore. Design/methodology/approach – The research methodology is based on critical review of the literature to identify the potentially most suitable strategic positioning methodology, evaluation and testing of the methodology within the context of SME's in Singapore, and analysis to determine the strengths and weaknesses of the methodology and opportunities for further research. Findings – This paper illustrates a leading integrated strategic positioning decision making process, which has been found to be potentially suitable for SMEs in Singapore, and the process is then applied and evaluated in two industrial case studies. Results in the form of strengths, weaknesses and opportunities are evaluated and discussed in detail, and further research to improve the process has been identified. Practical implications – A practical and integrated strategic supply chain positioning methodology for SMEs to define their own competitive space, among other companies in the manufacturing supply chain, so as to maximize business competitiveness. Originality/value – This paper contributes to the knowledge of the strategic positioning decision process as well as identifies further research to adapt the process for SMEs in Singapore.
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The role of interest and agency in the creation and transformation of institutions, in particular the “paradox of embedded agency” (Seo & Creed, 2002) have long puzzled institutional scholars. Most recently, Lawrence and Suddaby (2006) coined the term “institutional work” to describe various strategies for creating, maintaining and disrupting institutions. This label, while useful to integrate existing research, highlights institutionalists’ lack of attention to work as actors’ everyday occupational tasks and activities. Thus, the objective of this study is to take institutional work literally and ask: How does practical work come to constitute institutional work? Drawing on concepts of “situated change” (Orlikowski, 1996) I supplement existing macro-level perspectives of change with a microscopic, practice-based alternative. I examine the everyday work of English and German banking lawyers in a global law firm. Located at the intersection of local laws, international financial markets, commercial logics and professional norms, banking lawyers’ work regularly bridges different normative settings. Hence, they must constructively negotiate contradictory meanings, practices and logics to develop shared routines that resonate with different normative frameworks and facilitate task accomplishment. Based on observation and interview data, the paper distils a process model of banking transac-tions that highlights the critical interfaces forcing English and German banking lawyers into cross-border sensemaking. It distinguishes two accounts of cross-border sensemaking: the “old story” in which contradictory practices and norms collide and the “new story” of a synthetic set of practices for collaboratively “editing” (Sahlin-Andersson, 1996) legal documentation. Data show how new practices gain shape and legitimacy over a series of dialectic contests unfolding at work and how, in turn, these contests shift institutional logics as lawyers ‘get the deal done’. These micro-mechanisms suggest that as practical and institutional work blend, everyday work-ing practices come to constitute a form of institutional agency that is situated, emergent, dialectic and, therefore, embedded.
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This paper uses a practice perspective to study coordinating as dynamic activities that are continuously created and modified in order to enact organizational relationships and activities. It is based on the case of Servico, an organization undergoing a major restructuring of its value chain in response to a change in government regulation. In our case, the actors iterate between the abstract concept of a coordinating mechanism referred to as end-to-end management and its performance in practice. They do this via five performative–ostensive cycles: (1) enacting disruption, (2) orienting to absence, (3) creating elements, (4) forming new patterns, and (5) stabilizing new patterns. These cycles and the relationships between them constitute a process model of coordinating. This model highlights the importance of absence in the coordinating process and demonstrates how experiencing absence shapes subsequent coordinating activity.
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This thesis addresses the question of how business schoolsestablished as public privatepartnerships (PPPs) within a regional university in the English-speaking Caribbean survived for over twenty-one years and achieved legitimacy in their environment. The aim of the study was to examine how public and private sector actors contributed to the evolution of the PPPs. A social network perspective provided a broad relational focus from which to explore the phenomenon and engage disciplinary and middle-rangetheories to develop explanations. Legitimacy theory provided an appropriate performance dimension from which to assess PPP success. An embedded multiple-case research design, with three case sites analysed at three levels including the country and university environment, the PPP as a firm and the subgroup level constituted the methodological framing of the research process. The analysis techniques included four methods but relied primarily on discourse and social network analysis of interview data from 40 respondents across the three sites. A staged analysis of the evolution of the firm provided the ‘time and effects’ antecedents which formed the basis for sense-making to arrive at explanations of the public-private relationship-influenced change. A conceptual model guided the study and explanations from the cross-case analysis were used to refine the process model and develop a dynamic framework and set of theoretical propositions that would underpin explanations of PPP success and legitimacy in matched contexts through analytical generalisation. The study found that PPP success was based on different models of collaboration and partner resource contribution that arose from a confluence of variables including the development of shared purpose, private voluntary control in corporate governance mechanisms and boundary spanning leadership. The study contributes a contextual theory that explains how PPPs work and a research agenda of ‘corporate governance as inspiration’ from a sociological perspective of ‘liquid modernity’. Recommendations for policy and management practice were developed.
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OBJECTIVE: To determine the accuracy, acceptability and cost-effectiveness of polymerase chain reaction (PCR) and optical immunoassay (OIA) rapid tests for maternal group B streptococcal (GBS) colonisation at labour. DESIGN: A test accuracy study was used to determine the accuracy of rapid tests for GBS colonisation of women in labour. Acceptability of testing to participants was evaluated through a questionnaire administered after delivery, and acceptability to staff through focus groups. A decision-analytic model was constructed to assess the cost-effectiveness of various screening strategies. SETTING: Two large obstetric units in the UK. PARTICIPANTS: Women booked for delivery at the participating units other than those electing for a Caesarean delivery. INTERVENTIONS: Vaginal and rectal swabs were obtained at the onset of labour and the results of vaginal and rectal PCR and OIA (index) tests were compared with the reference standard of enriched culture of combined vaginal and rectal swabs. MAIN OUTCOME MEASURES: The accuracy of the index tests, the relative accuracies of tests on vaginal and rectal swabs and whether test accuracy varied according to the presence or absence of maternal risk factors. RESULTS: PCR was significantly more accurate than OIA for the detection of maternal GBS colonisation. Combined vaginal or rectal swab index tests were more sensitive than either test considered individually [combined swab sensitivity for PCR 84% (95% CI 79-88%); vaginal swab 58% (52-64%); rectal swab 71% (66-76%)]. The highest sensitivity for PCR came at the cost of lower specificity [combined specificity 87% (95% CI 85-89%); vaginal swab 92% (90-94%); rectal swab 92% (90-93%)]. The sensitivity and specificity of rapid tests varied according to the presence or absence of maternal risk factors, but not consistently. PCR results were determinants of neonatal GBS colonisation, but maternal risk factors were not. Overall levels of acceptability for rapid testing amongst participants were high. Vaginal swabs were more acceptable than rectal swabs. South Asian women were least likely to have participated in the study and were less happy with the sampling procedure and with the prospect of rapid testing as part of routine care. Midwives were generally positive towards rapid testing but had concerns that it might lead to overtreatment and unnecessary interference in births. Modelling analysis revealed that the most cost-effective strategy was to provide routine intravenous antibiotic prophylaxis (IAP) to all women without screening. Removing this strategy, which is unlikely to be acceptable to most women and midwives, resulted in screening, based on a culture test at 35-37 weeks' gestation, with the provision of antibiotics to all women who screened positive being most cost-effective, assuming that all women in premature labour would receive IAP. The results were sensitive to very small increases in costs and changes in other assumptions. Screening using a rapid test was not cost-effective based on its current sensitivity, specificity and cost. CONCLUSIONS: Neither rapid test was sufficiently accurate to recommend it for routine use in clinical practice. IAP directed by screening with enriched culture at 35-37 weeks' gestation is likely to be the most acceptable cost-effective strategy, although it is premature to suggest the implementation of this strategy at present.
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Background: Screening for congenital heart defects (CHDs) relies on antenatal ultrasound and postnatal clinical examination; however, life-threatening defects often go undetected. Objective: To determine the accuracy, acceptability and cost-effectiveness of pulse oximetry as a screening test for CHDs in newborn infants. Design: A test accuracy study determined the accuracy of pulse oximetry. Acceptability of testing to parents was evaluated through a questionnaire, and to staff through focus groups. A decision-analytic model was constructed to assess cost-effectiveness. Setting: Six UK maternity units. Participants: These were 20,055 asymptomatic newborns at = 35 weeks’ gestation, their mothers and health-care staff. Interventions: Pulse oximetry was performed prior to discharge from hospital and the results of this index test were compared with a composite reference standard (echocardiography, clinical follow-up and follow-up through interrogation of clinical databases). Main outcome measures: Detection of major CHDs – defined as causing death or requiring invasive intervention up to 12 months of age (subdivided into critical CHDs causing death or intervention before 28 days, and serious CHDs causing death or intervention between 1 and 12 months of age); acceptability of testing to parents and staff; and the cost-effectiveness in terms of cost per timely diagnosis. Results: Fifty-three of the 20,055 babies screened had a major CHD (24 critical and 29 serious), a prevalence of 2.6 per 1000 live births. Pulse oximetry had a sensitivity of 75.0% [95% confidence interval (CI) 53.3% to 90.2%] for critical cases and 49.1% (95% CI 35.1% to 63.2%) for all major CHDs. When 23 cases were excluded, in which a CHD was already suspected following antenatal ultrasound, pulse oximetry had a sensitivity of 58.3% (95% CI 27.7% to 84.8%) for critical cases (12 babies) and 28.6% (95% CI 14.6% to 46.3%) for all major CHDs (35 babies). False-positive (FP) results occurred in 1 in 119 babies (0.84%) without major CHDs (specificity 99.2%, 95% CI 99.0% to 99.3%). However, of the 169 FPs, there were six cases of significant but not major CHDs and 40 cases of respiratory or infective illness requiring medical intervention. The prevalence of major CHDs in babies with normal pulse oximetry was 1.4 (95% CI 0.9 to 2.0) per 1000 live births, as 27 babies with major CHDs (6 critical and 21 serious) were missed. Parent and staff participants were predominantly satisfied with screening, perceiving it as an important test to detect ill babies. There was no evidence that mothers given FP results were more anxious after participating than those given true-negative results, although they were less satisfied with the test. White British/Irish mothers were more likely to participate in the study, and were less anxious and more satisfied than those of other ethnicities. The incremental cost-effectiveness ratio of pulse oximetry plus clinical examination compared with examination alone is approximately £24,900 per timely diagnosis in a population in which antenatal screening for CHDs already exists. Conclusions: Pulse oximetry is a simple, safe, feasible test that is acceptable to parents and staff and adds value to existing screening. It is likely to identify cases of critical CHDs that would otherwise go undetected. It is also likely to be cost-effective given current acceptable thresholds. The detection of other pathologies, such as significant CHDs and respiratory and infective illnesses, is an additional advantage. Other pulse oximetry techniques, such as perfusion index, may enhance detection of aortic obstructive lesions.
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This paper explains how dynamic client portfolios can be a source of ambidexterity (i.e., exploration and exploitation) for knowledge-intensive firms (KIFs). Drawing from a unique qualitative dataset of firms in the global reinsurance market, we show how different types of client relationships underpin a dynamic client portfolio and become a source of ambidexterity for a KIF. We develop a process model to show how KIFs attain knowledge by segmenting their client portfolios, use that knowledge to explore and exploit within and across their client relationships, and dynamically adjust their client portfolios over time. Our study contributes to the literature on external sources of ambidexterity and dynamic management of client knowledge within KIFs.
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It has been reported that high-speed communication network traffic exhibits both long-range dependence (LRD) and burstiness, which posed new challenges in network engineering. While many models have been studied in capturing the traffic LRD, they are not capable of capturing efficiently the traffic impulsiveness. It is desirable to develop a model that can capture both LRD and burstiness. In this letter, we propose a truncated a-stable LRD process model for this purpose, which can characterize both LRD and burstiness accurately. A procedure is developed further to estimate the model parameters from real traffic. Simulations demonstrate that our proposed model has a higher accuracy compared to existing models and is flexible in capturing the characteristics of high-speed network traffic. © 2012 Springer-Verlag GmbH.
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This paper describes work conducted as a joint collaboration between the Virtual Design Team (VDT) research group at Stanford University (USA) , the Systems Engineering Group (SEG) at De Montfort University (UK) and Elipsis Ltd . We describe a new docking methodology in which we combine the use of two radically different types of organizational simulation tool. The VDT simulation tool operates on a standalone computer, and employs computational agents during simulated execution of a pre-defined process model (Kunz, 1998). The other software tool, DREAMS , operates over a standard TCP/IP network, and employs human agents (real people) during a simulated execution of a pre-defined process model (Clegg, 2000).
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Guided by theory in both the trust and leadership domains, the overarching aim of this thesis was to answer a fundamental question. Namely, how and when does trust-building between leaders and followers enhance leader-member exchange (LMX) development and organisational trust? Although trust is considered to be at the crux of the leader-follower relationship, surprisingly little theoretical or empirical attention has been devoted to understanding the precise nature of this relationship. By integrating both a typology of trustworthy behaviour and a process model of trust development with LMX theory, study one developed and tested a new model of LMX development with leader-follower trust-building as the primary mechanism. In a three wave cross-lagged design, 294 student dyads in a business simulation completed measures of trust perceptions and LMX across the first 6 months of the LMX relationship. Trust-building was found to account for unexplained variance in the LMX construct over time, while controlling for initial relationship quality, thus confirming the critical role of the trust-building process in LMX development. The strongest evidence was found for the role of integrity-based trust-building behaviour, albeit only when such behaviour was not attributed to insincere motives. The results for ability and benevolence-based trustworthy behaviour revealed valued insights into the developmental nature of trustworthiness perceptions within LMX relationships. Thus, the pattern of results in study one provided a more comprehensive and nuanced understanding of the dynamic interplay between trust and LMX. In study two, leader trust-building was investigated cross-sectionally within an organisational sample of 201 employees. The central aim of this study was to investigate whether leader trust-building within leader-follower relationships could be leveraged for organisational trust. As expected, the trust-building process instigated by members in study one was replicated for leaders in study two. In addition, the results were most consistent for benevolence-based trust building, whereas both integrity- and ability-based trust-building were moderated by the position of the leader within the organisation’s hierarchy. Overall, the findings of this thesis shed considerable light on the richness of trusting perceptions in organisations, and the critical role of trust-building in LMX development and organisational trust.
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Optimal design for parameter estimation in Gaussian process regression models with input-dependent noise is examined. The motivation stems from the area of computer experiments, where computationally demanding simulators are approximated using Gaussian process emulators to act as statistical surrogates. In the case of stochastic simulators, which produce a random output for a given set of model inputs, repeated evaluations are useful, supporting the use of replicate observations in the experimental design. The findings are also applicable to the wider context of experimental design for Gaussian process regression and kriging. Designs are proposed with the aim of minimising the variance of the Gaussian process parameter estimates. A heteroscedastic Gaussian process model is presented which allows for an experimental design technique based on an extension of Fisher information to heteroscedastic models. It is empirically shown that the error of the approximation of the parameter variance by the inverse of the Fisher information is reduced as the number of replicated points is increased. Through a series of simulation experiments on both synthetic data and a systems biology stochastic simulator, optimal designs with replicate observations are shown to outperform space-filling designs both with and without replicate observations. Guidance is provided on best practice for optimal experimental design for stochastic response models. © 2013 Elsevier Inc. All rights reserved.