168 research outputs found

    Driving continuous improvement

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    The quality of improvement depends on the quality of leading and lagging performance indicators. For this reason, several tools, such as process mapping, cause and effect analysis and FMEA, need to be used in an integrated way with performance measurement models, such as balanced scorecard, integrated performance measurement system, performance prism and so on. However, in our experience, this alone is not quite enough due to the amount of effort required to monitor performance indicators at operational levels. The authors find that IT support is key to the successful implementation of performance measurement-driven continuous improvement schemes

    Electrohydrodynamic manipulation of multiphase fluids

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    In microfluidic devices, the fluid can be manipulated either as continuous streams or droplets. The latter is particularly attractive as individual droplets can not only move but also split and fuse, thus offer a greater flexibility in applications such as a laboratory-on- a-chip. In this thesis, a technique is developed that uses an externally applied electric field for manipulating and removing particles trapped on the surface of a drop. The drop is assumed to be immersed in another liquid with which it is immiscible, and the electric field is generated by placing electrodes on the sides of the microdevice. Both experiments and direct numerical simulation (DNS) approaches are used to study these problems. The DNS approach used in this thesis is based on a finite element scheme in which the fundamental equations of motion for the droplets and the surrounding fluid are solved exactly within numerical errors. The interface is tracked by the level set method and the electrostatic forces are computed using the Maxwell stress tensor approach. The distributed Lagrange multiplier method is used for tracking particles. One of the main results of this work is that the distribution of particles on the surface of a drop can be manipulated by subjecting it to a uniform electric field and these concentrated particles can then be removed by further increasing the electric field intensity. Specifically, it is shown that particles can be concentrated into well-defined regions on the drop surface while leaving the rest of the surface particle free. Experiments show that when the dielectric constant of the drop is greater than that of the ambient liquid, particles for which the Clausius-Mossotti factor is positive move along to the two poles of the drop. Particles with a negative Clausius-Mossotti factor, on the other hand, form a ring near the drop equator. This motion is due to the dielectrophoretic force that acts upon particles because the electric field on the surface of the drop is nonuniform, despite the fact that the applied electric field away from the drop is uniform. Experiments also show that when small particles collect at the poles of a deformed drop, the electric field needed to break the drop is smaller than it is without the particles. Also, the experimental results for the dependence of the dielectrophoretic force on the parameters of the system such as the particles\u27 and drop\u27s radii and the dielectric properties of the fluids and particles are studied, and a dimensionless parameter regime for which the technique is guaranteed to work is defined. Also it is shown that this technique can be used to separate particles experiencing positive dielectrophoresis on the surface of a drop from those experiencing negative dielectrophoresis, and form a composite (Janus) drop by aggregating particles of one type near the poles and of another near the equator. The DNS approach is used to study the transport of particles via the traveling wave dielectrophoretic (twDEP) forces. This technique offers a promising method for transporting particles along the length of a channel without having to pump the liquid itself Since the magnitudes of twDEP forces and torque vary with the frequency of the electric field, a variety of complex dynamical regimes are possible. The DNS approach is used to analyze the various dynamical regimes for yeast cells in terms of the forces that act on the cells, i.e., the conventional dielectrophoretic and traveling wave dielectrophoretic force and torque, the viscous drag exerted by the fluid on the particle, and the electrostatic and hydrodynamic particle-particle interactions

    Error Reduction and Effect of Step Size in Adjustment Calculus for Cam Applications

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    Any measurement, however carefully done, will never be free from errors. Similarly, machining of cams for automobiles is prone to contain errors. These errors are naturally a part and parcel of cam manufacturing. The nature of deviations of the manufactured cam profile from the theoretical cam determines its usability. Sometimes, allowable deviations in high speed cams may be in the order of 2540 ”m. Larger deviations will disqualify the cams for applications. Velocity and acceleration of the cam are estimated from the measured displacement of the cam follower during quality control implementation. This data helps in eliminating the unfit cams. Existing methods deal with a notorious challenge from propagation of measurement errors in the displacement data to predicted velocity and acceleration values. J. Oderfeld developed a little known method called ‘Adjustment Calculus’ which is an alternative method for this purpose. This method combines the ‘marching point’ method that fits a polynomial to discrete data and a symmetric Stirling interpolation method. Until now, adjustment calculus has been applied to reduce errors in acceleration data. In this work, adjustment calculus is implemented to velocity predictions. ‘Weights’ for calculation of adjusted velocity are derived using a cubic polynomial fit and symmetric Stirling interpolation formula. The effect of step size on application of adjustment calculus to different cam profiles is probed using the Monte Carlo method. Effective step size for practical applications in automotive cam quality control is suggested for each cam profile. Practical pointers for application to cam inspection for velocity and acceleration analysis are formulated. Adviser: Wieslaw M. Szydlowsk

    Negotiation Based Resource Allocation to Control Information Diffusion

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    Study of diffusion or propagation of information over a network of connected entities play a vital role in understanding and analyzing the impact of such diffusion, in particular, in the context of epidemiology, and social and market sciences. Typical concerns addressed by these studies are to control the diffusion such that influence is maximally (in case of opinion propagation) or minimally (in case of infectious disease) felt across the network. Controlling diffusion requires deployment of resources and often availability of resources are socio-economically constrained. In this context, we propose an agent-based framework for resource allocation, where agents operate in a cooperative environment and each agent is responsible for identifying and validating control strategies in a network under its control. The framework considers the presence of a central controller that is responsible for negotiating with the agents and allocate resources among the agents. Such assumptions replicates real-world scenarios, particularly in controlling infection spread, where the resources are distributed by a central agency (federal govt.) and the deployment of resources are managed by a local agency (state govt.). If there exists an allocation that meets the requirements of all the agents, our framework is guaranteed to find one such allocation. While such allocation can be obtained in a blind search methods (such as checking the minimum number of resources required by each agent or by checking allocations between each pairs), we show that considering the responses from each agent and considering allocation among all the agents results in a “negotiation” based technique that converges to a solution faster than the brute force methods. We evaluated our framework using data publicly available from Stanford Network Analysis Project to simulate different types of networks for each agents

    Dynamics of performance measurement and organizational culture

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    This research paper aims to model the dynamic relationship between performance measurement, management styles and organisational culture, in order to develop a better understanding of the causal linkages between these three areas

    Influence of Culture and Management Systems on PMS

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    Purpose: The aim of this study is to find and explore the relationships between organizational culture, management Systems and the implementation and Operationalisation aspects of Performance Measurement Systems (PMS). Design/methodology/approach: The relevant literature on organizational culture, Organizational behavior, Strategic management and management accounting, in the context of performance measurement systems, will be examined. A structured questionnaire will be used to survey the views of the top management teams of a suitable sample of organizations. The survey implementation process will follow four steps: pre-­‐notification, initial mailing, first follow up and, second follow up. Findings: As this is a developmental paper, it is not possible to provide definite findings at this point. However, it is anticipated to find out relationship between Culture, Management systems and PMS. Practical implications: The findings of this study will provide managers with better understanding of the relationship between organizational culture, management systems and PMS. This will in turn help them to provide a successful PMS. Originality/value: No research has been done to find out the relationship between organizational culture, management systems and two aspects of PMS, namely implementation and operationalisation aspects, using a large-­‐scale sample approach. The findings of this research therefore will provide useful insights and methods for future researchers in this area

    E-Waste Policy in Developing Countries: The Context of Nigeria

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    The use of ICTs in developing countries has grown significantly since the start of the 21st century (ITU 2012), driven on by encouraging evidence and literature that associates ICTs with various aspects of economic and social development (UNCTAD 2011). However, ICT equipment, which is supposed to help developing countries improve education and stimulate economic growth may undermine the sustainability of ICT use, and have negative impact on human health, and the environment, if not addressed. The environmental concerns regarding e-waste stem from the hazardous elements and compounds that can be found in everyday e-waste. These compounds are known to have adverse impacts on the health of the environment and all living beings. Most developing countries, including Nigeria, have neither a well-established system of disposal of e-waste nor a legislation dealing specifically with e-waste and a lax enforcement of existing laws dealing with general waste management. (Nnrom and Osibanjo, 2008) The aim of this paper is to discuss a theoretical framework which will be used as a ‘sensitizing device’ for a qualitative study of the issues and challenges associated with waste policy formulation and implementation process in Edo state, Nigeria.(Myers, 1977)

    Value co-creation in the delivery of outcome-based contracts for business-to-business service

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    Working paperThis study introduces the concept of outcome-based contracting (OBC) as the mechanism for firms to focus on delivering value-in-use, and as the driver for value co-creation as the firm would need to jointly deliver outcomes with the customer. The paper analyses two OBC-type contracts between the UK Ministry of Defence and two of its industrial partners. We find that in delivering to outcomes and achieving value-in-use, the state-dependent nature of value in usage „pushes back‟ into the organization, requiring the firm to re-evaluate the way they are structured to receive changes from customer state-dependencies so as to deliver a better service. Our analysis presents seven generic attributes of value co-creation (AVCs) essential for the capability to deliver value-in-use. These are behavioral alignment, process alignment, congruence in customer expectations, congruence in firm expectations, empowerment and perceived control, behavioral transformation, and complementary competencies. The attributes discovered through qualitative data were matched with previous academic literature and operationalized and a measurement instrument was developed. The instrument was then validated by performing an exploratory and second order confirmatory factor analysis.This research was made possible through the joint funding of the Engineering & Physical Science Research Council (UK) and BAE Systems on the Support Service Solutions: Strategy & Transition (S4T) project consortium led by the University of Cambridge. The authors gratefully acknowledge the staff of BAE Systems and MBDA as well as members of the ADAPT IPT, 16th Regiment, ATTAC IPT, MoD and the RAF who have all contributed substantially towards this research

    Strategic sourcing with multi-stakeholders through value co-creation: An evidence from global health care company

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    This paper explores how a firm is able to consider the value co-creation potential of its suppliers, mediate the goals and actions of both its external and internal stakeholders, and develop strategic supplier partnerships that go beyond compliance to contractual agreements to innovative value co-creation activities. The study contributes to filling a knowledge gap in understanding the process of value co-creation in a service context by providing empirical evidence, by means of case-based action research in a global healthcare company (HCC), on strategic multi-sourcing decision-making and value co-creation within multi-stakeholdersŚł collaborative partnerships. The case-based action research discussed in the paper lays a foundation for normative theories of multi-stakeholder multi-souring strategic decision-making. The paper describes how the firm uses the Kraljic portfolio purchasing matrix for initial screening of potential suppliers; identifies multiple stakeholders and mediates multiple stakeholder goals to establish behavioural factors for strategic sourcing decision-making and evaluating the effectiveness of multi-stakeholder collaborative decision-making during the process to develop a value co-creation system. The arguments and findings draw attention to a number of specific stakeholder expectations and goals that need to be considered before embarking on a strategy of a collaborative multi-stakeholder supplier innovation strategy. The findings of the research vindicate and qualify the approach used to develop an innovative collaborative partnership through stakeholder mediation to co-create value
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