Competitive edge through operations management

A view has emerged within manufacturing and service organizations that the operations management function can hold the key to achieving competitive edge. This has recently been emphasized by the demands for greater variety and higher quality which must be set against a background of increasing cost of resources. As nations' trade barriers are progressively lowered and removed, so producers of goods and service products are becoming more exposed to competition that may come from virtually anywhere around the world. To simply survive in this climate many organizations have found it necessary to improve their manufacturing or service delivery systems. To become real ''winners'' some have adopted a strategic approach to operations and completely reviewed and restructured their approach to production system design and operations planning and control. The articles in this issue of the International journal of Operations & Production Management have been selected to illustrate current thinking and practice in relation to this situation. They are all based on papers presented to the Sixth International Conference of the Operations Management Association-UK which was held at Aston University in June 1991. The theme of the conference was "Achieving Competitive Edge" and authors from 15 countries around the world contributed to more than 80 presented papers. Within this special issue five topic areas are addressed with two articles relating to each. The topics are: strategic management of operations; managing change; production system design; production control; and service operations. Under strategic management of operations De Toni, Filippini and Forza propose a conceptual model which considers the performance of an operating system as a source of competitive advantage through the ''operation value chain'' of design, purchasing, production and distribution. Their model is set within the context of the tendency towards globalization. New's article is somewhat in contrast to the more fashionable literature on operations strategy. It challenges the validity of the current idea of ''world-class manufacturing'' and, instead, urges a reconsideration of the view that strategic ''trade-offs'' are necessary to achieve a competitive edge. The importance of managing change has for some time been recognized within the field of organization studies but its relevance in operations management is now being realized. Berger considers the use of "organization design", ''sociotechnical systems'' and change strategies and contrasts these with the more recent idea of the ''dialogue perspective''. A tentative model is suggested to improve the analysis of different strategies in a situation specific context. Neely and Wilson look at an essential prerequisite if change is to be effected in an efficient way, namely product goal congruence. Using a case study as its basis, their article suggests a method of measuring goal congruence as a means of identifying the extent to which key performance criteria relating to quality, time, cost and flexibility are understood within an organization. The two articles on production systems design represent important contributions to the debate on flexible production organization and autonomous group working. Rosander uses the results from cases to test the applicability of ''flow groups'' as the optimal way of organizing batch production. Schuring also examines cases to determine the reasons behind the adoption of ''autonomous work groups'' in The Netherlands and Sweden. Both these contributions help to provide a greater understanding of the production philosophies which have emerged as alternatives to more conventional systems -------for intermittent and continuous production. The production control articles are both concerned with the concepts of ''push'' and ''pull'' which are the two broad approaches to material planning and control. Hirakawa, Hoshino and Katayama have developed a hybrid model, suitable for multistage manufacturing processes, which combines the benefits of both systems. They discuss the theoretical arguments in support of the system and illustrate its performance with numerical studies. Slack and Correa's concern is with the flexibility characteristics of push and pull material planning and control systems. They use the case of two plants using the different systems to compare their performance within a number of predefined flexibility types. The two final contributions on service operations are complementary. The article by Voss really relates to manufacturing but examines the application of service industry concepts within the UK manufacturing sector. His studies in a number of companies support the idea of the ''service factory'' and offer a new perspective for manufacturing. Harvey's contribution by contrast, is concerned with the application of operations management principles in the delivery of professional services. Using the case of social-service provision in Canada, it demonstrates how concepts such as ''just-in-time'' can be used to improve service performance. The ten articles in this special issue of the journal address a wide range of issues and situations. Their common aspect is that, together, they demonstrate the extent to which competitiveness can be improved via the application of operations management concepts and techniques.

Indirect ties in knowledge networks:a social network analysis with ordered weighted averaging operators

This PhD thesis analyses networks of knowledge flows, focusing on the role of indirect ties in the knowledge transfer, knowledge accumulation and knowledge creation process. It extends and improves existing methods for mapping networks of knowledge flows in two different applications and contributes to two stream of research. To support the underlying idea of this thesis, which is finding an alternative method to rank indirect network ties to shed a new light on the dynamics of knowledge transfer, we apply Ordered Weighted Averaging (OWA) to two different network contexts. Knowledge flows in patent citation networks and a company supply chain network are analysed using Social Network Analysis (SNA) and the OWA operator. The OWA is used here for the first time (i) to rank indirect citations in patent networks, providing new insight into their role in transferring knowledge among network nodes; and to analyse a long chain of patent generations along 13 years; (ii) to rank indirect relations in a company supply chain network, to shed light on the role of indirectly connected individuals involved in the knowledge transfer and creation processes and to contribute to the literature on knowledge management in a supply chain. In doing so, indirect ties are measured and their role as means of knowledge transfer is shown. Thus, this thesis represents a first attempt to bridge the OWA and SNA fields and to show that the two methods can be used together to enrich the understanding of the role of indirectly connected nodes in a network. More specifically, the OWA scores enrich our understanding of knowledge evolution over time within complex networks. Future research can show the usefulness of OWA operator in different complex networks, such as the on-line social networks that consists of thousand of nodes.

Groups with the Minimal Condition on Non-���Nilpotent-by-Finite��� Subgroups

We characterize the groups which do not have non-trivial perfect sections and such that any strictly descending chain of non-���nilpotent-by-finite��� subgroups is finite.

Progmosis:evaluating risky individual behavior during epidemics using mobile network data

The possibility to analyze, quantify and forecast epidemic outbreaks is fundamental when devising effective disease containment strategies. Policy makers are faced with the intricate task of drafting realistically implementable policies that strike a balance between risk management and cost. Two major techniques policy makers have at their disposal are: epidemic modeling and contact tracing. Models are used to forecast the evolution of the epidemic both globally and regionally, while contact tracing is used to reconstruct the chain of people who have been potentially infected, so that they can be tested, isolated and treated immediately. However, both techniques might provide limited information, especially during an already advanced crisis when the need for action is urgent. In this paper we propose an alternative approach that goes beyond epidemic modeling and contact tracing, and leverages behavioral data generated by mobile carrier networks to evaluate contagion risk on a per-user basis. The individual risk represents the loss incurred by not isolating or treating a specific person, both in terms of how likely it is for this person to spread the disease as well as how many secondary infections it will cause. To this aim, we develop a model, named Progmosis, which quantifies this risk based on movement and regional aggregated statistics about infection rates. We develop and release an open-source tool that calculates this risk based on cellular network events. We simulate a realistic epidemic scenarios, based on an Ebola virus outbreak; we find that gradually restricting the mobility of a subset of individuals reduces the number of infected people after 30 days by 24%.

Uncertainty propagation in the model web:a case study with e-Habitat

eHabitat is a Web Processing Service (WPS) designed to compute the likelihood of finding ecosystems with equal properties. Inputs to the WPS, typically thematic geospatial "layers", can be discovered using standardised catalogues, and the outputs tailored to specific end user needs. Because these layers can range from geophysical data captured through remote sensing to socio-economical indicators, eHabitat is exposed to a broad range of different types and levels of uncertainties. Potentially chained to other services to perform ecological forecasting, for example, eHabitat would be an additional component further propagating uncertainties from a potentially long chain of model services. This integration of complex resources increases the challenges in dealing with uncertainty. For such a system, as envisaged by initiatives such as the "Model Web" from the Group on Earth Observations, to be used for policy or decision making, users must be provided with information on the quality of the outputs since all system components will be subject to uncertainty. UncertWeb will create the Uncertainty-Enabled Model Web by promoting interoperability between data and models with quantified uncertainty, building on existing open, international standards. It is the objective of this paper to illustrate a few key ideas behind UncertWeb using eHabitat to discuss the main types of uncertainties the WPS has to deal with and to present the benefits of the use of the UncertWeb framework.

��zleti kapcsolatok modellez��se (Modelling business relations)

Ebben a tanulm��nyban az ell��t��si l��ncok egyik ��p��t��elem��t, az ell��t��si l��ncokban egy��ttm��k��d�� diadikus kapcsolatokat ��ll��tjuk a vizsg��latok k��z��ppontj��ba. Az irodalomban sz��mtalan megk��zel��t��s ismert az ilyen t��pus�� megrendel��-besz��ll��t�� v��llalatok k��z��tti kapcsolatok fejl��d��s��nek le��r��s��ra. Az egyes fejl��d��si elm��letek a diadikus kapcsolatok id��beli alakul��s��t elm��leti szinten t��rgyalj��k, de az empirikus vizsg��latokat nem v��geznek. Ebben a tanulm��nyban mi k��s��rletet tesz��nk az ell��t��si l��nc t��pus�� kapcsolatok fejl��d��s��nek empirikus vizsg��lat��ra. Arra pr��b��lunk v��laszt tal��lni, hogy alkalmazhat��-e az ��letciklus-hipot��zis az ��zleti kapcsolatok id��beli fejl��d��s��nek le��r��s��ra. (===) The study places in the centre of discussion the cooperative dyadic relations that form one element in the chain of supply. Writers have taken numerous approaches to describing the development of such relations between buyer and supplier firms. The various theories discuss on a theoretical level the development over time of these dyadic relations, but they eschew empirical examinations. An attempt is made in this study to conduct such an empirical examination of the chain-like relations of supply, with the aim of discovering whether the life-cycle hypothesis can be applied to the development of business relations over time.

Climate change impacts on migration and labour market

Floods, droughts and monsoons have always disturbed human settlements, but there are more settlements now and more people in the world. Therefore, if a natural disaster happens, more will suffer than ever before. Moreover, climate in the past several decades has been greatly degraded by anthropogenic activity. In some cases, the chain of causality of human influence on the climate is direct and unambiguous (e.g. the effects of irrigation on local humidity), though there are instances where it is less clear. Presently, the scientific consensus (IPCC, 2007) on climate change is that human activity is very likely the cause for the rapid increase of global average temperatures, more generally known as global warming.

Consumo c(l)iente: abordagem do g��nero an��ncio publicit��rio em livros did��ticos de l��ngua portuguesa do ensino m��dio

Portuguese language textbooks, according to what has been preconized on the official document to education, have been configured on discursive genres imported from diverse spheres of human activity. Adverts, genre of ample social circulation, spread from the Advertising sphere to the schools and started being approached by these collectaneas as an object and a tool for teaching. Therefore, this research deals with the approach of ads in Portugese textbooks. These discursive practices matter for the impact or appeal they exert over the (new) consumers, among which High School students; for their representation in the capitalist system, which guides us on our relationships and social practices; and for the mix of languages that end up at their composition, once they encapsulate the spirit of our time, par excellence, the one from the verbal-visual genres. To understand the treatment given to these advertising pieces, from questions/commentaries related to them, two collections were selected by the Programa Nacional do Livro Did��tico ��� Textbook National Program (PNLD 2012) among the ones more used by public High Schools in Natal/RN. From Applied Linguistics, from mestizo, nomadic and inter/transdisciplinary identity (MOITA LOPES, 2009), this study falls within the discursive chain of the interpretive tradition of historical-cultural approach (FREITAS, 2010) and names the Bakhtin Circle and its language���s dialogical conception as inescapable partners. The data of the colletaneas show that the genre approach can happen as concrete utterance, as linguistic artifact and as hybrid, at work with questions and without questions, with the predominance of its occurrence in the portion of the volume devoted to the study of grammar. In the literature chapters and production/interpretation of compositions, it insert is incipient or it doesn���t happen in the volume. Such a provision has implications for multiliteracies (ROJO, 2012) of the citizen student, once the lack or the abundance of critical reading proposals for this genre, that demand from the student the exercise of knowledge that is necessary to the construction of linguistic and social meanings, can be responsible for guide to a more conscious consumerism (material and cultural) by the chief customers of the work under review. The approaches of the genres seems to indicate a gradual transition that such material have undergone, which means, from the focus on clauses to the focus on utterances, or even the approach as linguistic artifact to hybrid and the concrete utterance, in search of overcoming the traditional tendency of taking advantage of formal aspects of the language, to the detriment of enunciative ones, and for coming into harmony with the guidelines and parameters of teaching in contemporary times, bringing the school duties close to the rights in life.

Dispersion and energy relations in periodic chains and grids

In this study wave propagation, dispersion relations, and energy relations for linear elastic periodic systems are analyzed. In particular, the dispersion relations for monoatomic chain of infinite dimension are obtained analytically by writing the Block-type wave equation for a unit cell in order to capture the dynamic behavior for chains under prescribed vibration. By comparing the discretized model (mass-spring chain) with the solid bar system, the nonlinearity of the dispersion relation for chain indicates that the periodic lattice is dispersive in contrast to the continuous rod, which is non dispersive. Further investigations have been performed considering one-dimensional diatomic linear elastic mass-spring chain. The dispersion relations, energy velocity, and group velocity have been derived. At certain range of frequencies harmonic plane waves do not propagate in contrast with monoatomic chain. Also, since the diatomic chain considered is a linear elastic chain, both of the energy velocity and the group velocity are identical. As long as the linear elastic condition is considered the results show zero flux condition without residual energy. In addition, this paper shows that the diatomic chain dispersion relations are independent on the unit cell scheme. Finally, an extension for the study covers the dispersion and energy relations for 2D- grid system. The 2x2 grid system show a periodicity of the dispersion surface in the wavenumber domain. In addition, the symmetry of the surface can be exploited to identify an Irreducible Brillouin Zone (IBZ). Compact representations of the dispersion properties of multidimensional periodic systems are obtained by plotting frequency as the wave vector���s components vary along the boundary of the IBZ, which leads to a widely accepted and effective visualization of bandgaps and overall dispersion properties.

Sub-wavelength resonators as seismic Rayleigh waves shield

We explore the thesis that tall structures can be protected by means of seismic metamaterials. Seismic metamaterials can be built as some elements are created over soil layer with different shapes, dimensions, patterns and from different materials. Resonances in these elements are acting as locally resonant metamaterials for Rayleigh surface waves in the geophysics context. Analytically we proved that if we put infinite chain of SDOF resonator over the soil layer as an elastic, homogeneous and isotropic material, vertical component of Rayleigh wave, longitudinal resonance of oscillators will couple with each other, they would create a Rayleigh bandgap frequency, and wave will experience attenuation before it reaches the structure. As it is impossible to use infinite chain of resonators over soil layer, we considered finite number of resonators throughout our simulations. Analytical work is interpreted using finite element simulations that demonstrates the observed attenuation is due to bandgaps when oscillators are arranged at sub-wavelength scale with respect to the incident Rayleigh wave. For wavelength less than 5 meters, the resulting bandgaps are remarkably large and strongly attenuating when impedance of oscillators matches impedance of soil. Since longitudinal resonance of SDOF resonator are proportional to its length inversely, a formed array of resonators that attenuates Rayleigh waves at frequency ���10 Hz could be designed starting from vertical pillars coupled to the ground. Optimum number of vertical pillars and their interval spacing called effective area of resonators are investigated. For 10 pillars with effective area of 1 meter and resonance frequency of 4.9 Hz, bandgap frequency causes attenuation and a sinusoidal impulsive force illustrate wave steering down phenomena. Simulation results proved analytical findings of this work.

La d��construction de l'onto-th��ologie par Jacques Derrida : d��tour litt��raire et mise en relief de la matrice langagi��re comme "diff��rance".

Le mouvement derridien de la diff��rance marque la rupture avec l'affirmation de la m��taphysique de la pr��sence, avec l'autorit�� du signifi�� transcendantal. Dans cet univers mouvant de signifiants qui se renvoient perp��tuellement les uns aux autres, la logique d'univocit�� se disloque. La "pr��sence" n'est que fantomatique, s'esquissant au sein d'une cha��ne ininterrompue de signifiants et se laissant toujours creuser par la marque d'un irr��ductible manque. Face au logocentrisme, corollaire de l'affirmation de la pr��sence, l'��criture se veut si��ge et articulation de la trace, d'une origine qui ne peut ��tre que ratur��e, v��hicule d'une irr��m��diable f��lure. La volet litt��raire de la d��construction a pour but de mettre en ��vidence le fonctionnement de l'"ind��cidabilit��" du discours, soit une certaine ambivalence dans la signification qui caract��rise tout texte. L'objectif principal de la pr��sente recherche est de fournir une compr��hension plus approfondie de la d��construction en insistant sur l'ancrage langagier de tout texte. Le discours philosophique n'��chappe ainsi pas au m��canisme diff��rentiel du langage et de la d��rive m��taphorique. La parent�� entre la perspective d��constructiviste derridienne et la conception mallarm��enne du langage po��tique semble frappante. La mise en oeuvre, par Mallarm��, d'une dislocation de l'espace textuel, son minutieux "creusement" du vers apr��s renoncement �� toute qu��te d'"Id��al", la mise en relief du leurre de l'appropriation langagi��re, voil�� qui trouve un ��cho particulier dans les th��ses derridiennes. La "mim��sis" platonicienne se voit au travers du prisme de la "mimique" mallarm��enne. La d��construction poursuit son travail de "luxation" de l'oreille philosophique, ins��rant les philosoph��mes dans la matrice langagi��re, les livrant ainsi au hasard du cheminement textuel et les confrontant �� l'aporie. La philosophie n'a alors d'autre choix que d'abandonner ses pr��tentions transcendantales. La marche de la "diff��rance" instaure une inexorable distance qui prive le sujet de tout rapport direct avec une origine assur��e et lui ��te toute possibilit�� de ma��trise sur le monde. Au travers de la langue, se profile la question de l'alt��rit��, de la relation dissym��trique qui nous lie �� cet "autre", ce "tout-autre" qui nous fonde et nous constitue. L'accueil inconditionnel de cette alt��rit�� nous m��nera �� l'��tude de la "religion", la d��construction se tournant vers le "religieux" tout en effectuant un "retournement" habile de tout credo essentialiste.

Efficient simulations with electronic open boundaries

We present a reformulation of the hairy-probe method for introducing electronic open boundaries that is appropriate for steady-state calculations involving nonorthogonal atomic basis sets. As a check on the correctness of the method we investigate a perfect atomic wire of Cu atoms and a perfect nonorthogonal chain of H atoms. For both atom chains we find that the conductance has a value of exactly one quantum unit and that this is rather insensitive to the strength of coupling of the probes to the system, provided values of the coupling are of the same order as the mean interlevel spacing of the system without probes. For the Cu atom chain we find in addition that away from the regions with probes attached, the potential in the wire is uniform, while within them it follows a predicted exponential variation with position. We then apply the method to an initial investigation of the suitability of graphene as a contact material for molecular electronics. We perform calculations on a carbon nanoribbon to determine the correct coupling strength of the probes to the graphene and obtain a conductance of about two quantum units corresponding to two bands crossing the Fermi surface. We then compute the current through a benzene molecule attached to two graphene contacts and find only a very weak current because of the disruption of the �� conjugation by the covalent bond between the benzene and the graphene. In all cases we find that very strong or weak probe couplings suppress the current.

PORBS: A parallel observation-based slicer

Abstract���This paper presents PORBS, a parallelised observation-based slicing tool. The tool itself is written in Java making it platform independent and leverages the build chain of the system being sliced to avoid the need to replicate complex compiler analysis. The target audience of PORBS is software engineers and researchers working with and on tools and techniques for software comprehension, debugging, re-engineering, and maintenance.

Melhoria de fluxos no armaz��m de componentes da Bosch Termotecnologia S.A.

A gest��o de um armaz��m de componentes de uma qualquer empresa produtiva �� uma das principais tarefas a desempenhar no seio desta, pois a mesma afecta toda a cadeia de abastecimento de entrega do produto final, sendo o armaz��m de componentes o in��cio da cadeia interna. Qualquer dificuldade que surja no desenrolar das actividades associadas poder�� causar impactos prejudiciais nos processos consequentes. A melhoria do principal processo do armaz��m, correspondente �� satisfa����o dos pedidos de material dos processos a jusante, �� algo que trar�� benef��cios a toda a cadeia, ao mesmo tempo que s��o melhoradas as condi����es de trabalho, eliminando o desperd��cio e tornando o processo mais eficiente. N��o obstante deste processo, ainda existe a necessidade de recolher e gerir informa����es referentes aos diferentes processos do armaz��m da maneira mais r��pida poss��vel, para actuar de acordo com as necessidades. A falta de informa����o relativamente ao estado de um processo tamb��m poder�� influenciar os processos seguintes de forma negativa. O projecto aqui apresentado foi realizado no armaz��m de componentes da Bosch Termotecnologia S.A., em Aveiro, tendo como objectivo mostrar a import��ncia da movimenta����o de material e tamb��m de informa����o dentro desta ��rea, criando ao mesmo tempo a melhoria tanto dos fluxos de material como dos fluxos de informa����o. Ser��o apresentadas diferentes implementa����es que foram desenvolvidas com o intuito de criar melhoria nos fluxos: a cria����o de novos fluxos de informa����o para o processo de recep����o de material, com o intuito de recolher informa����o que at�� agora n��o era percept��vel, para depois actuar na melhoria do processo; a cria����o de ��reas dedicadas dentro da ��rea de picking, de modo a atingir uma redu����o no n��mero de colaboradores afectos ao processo de picking; a implementa����o de uma c��lula de repacking, de modo a remover esta actividade do processo de picking; bem como todas as actividades realizadas com o objectivo de implementar as melhorias propostas.

The Brexit vote: A financial thunderclap with long-term consequences

The Brexit vote was a financial thunderclap for the entire Western chain of globalised finance. The EU and the Eurozone now face an unknown period of disintegration, instability and rebranding.