Dépouillements

Problem-structuring methods and project management / J. Davis in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 893–904 Titre : Problem-structuring methods and project management : an example of stakeholder involvement using hierarchical process modelling methodology Type de document : texte imprimé Auteurs : J. Davis, Auteur ; A. MacDonald, Auteur ; L. White, Auteur Année de publication : 2011 Article en page(s) : pp. 893–904 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Project  management  Problem-structuring  methods  Hierarchical  process  modelling  Stakeholder  engagement Index. décimale : 001.424 Résumé : Project Management has gained in importance over the last few decades and it is increasingly common in many types of organisations. Today there is a concern over the relevance of the more conventional project management approaches to problems that are increasingly complex and constrained and involve large numbers of interested parties or stakeholders. This paper examines the relevance of problem-structuring methods to project management, focusing on the front-end of managing complex projects and discusses stakeholder involvement using Hierarchical Process Modelling methodology. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201012a.html [article] Problem-structuring methods and project management : an example of stakeholder involvement using hierarchical process modelling methodology [texte imprimé] / J. Davis, Auteur ; A. MacDonald, Auteur ; L. White, Auteur . - 2011 . - pp. 893–904. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 893–904 Mots-clés : Project  management  Problem-structuring  methods  Hierarchical  process  modelling  Stakeholder  engagement Index. décimale : 001.424 Résumé : Project Management has gained in importance over the last few decades and it is increasingly common in many types of organisations. Today there is a concern over the relevance of the more conventional project management approaches to problems that are increasingly complex and constrained and involve large numbers of interested parties or stakeholders. This paper examines the relevance of problem-structuring methods to project management, focusing on the front-end of managing complex projects and discusses stakeholder involvement using Hierarchical Process Modelling methodology. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201012a.html

An ANP- and AHP-based approach for weighting criteria in public works bidding / J. P. Pastor-Ferrando in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 905–916 Titre : An ANP- and AHP-based approach for weighting criteria in public works bidding Type de document : texte imprimé Auteurs : J. P. Pastor-Ferrando, Auteur ; P. Aragonés-Beltrán, Auteur ; A. Hospitaler-Pérez, Auteur Année de publication : 2011 Article en page(s) : pp. 905–916 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Multiple  criteria  decision  analysis  Analytic  network  process  (ANP)  Analytic  hierarchy  process  (AHP)  Public  works  bidding  Criteria  weighting Index. décimale : 001.424 Résumé : When the bidding conditions for a new public works contract are officially published, the contracting authority should count with objective criteria and weights to evaluate tenders. The evaluation criteria and weights are obtained from official contract documents. In this paper a new approach for the selection and measurement of the bidding criteria based on Analytic Hierarchy Processes (AHP) and Analytic Network Processes (ANP) is proposed. A hierarchy model and a 21-criterion network model have been developed and applied to two real cases: the first one is devoted to study the public bidding for the construction of an educational centre at the Polytechnic University of Valencia, whereas the second one analyses the public bidding for the remodelling and improvement of one section of a national road. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201013a.html [article] An ANP- and AHP-based approach for weighting criteria in public works bidding [texte imprimé] / J. P. Pastor-Ferrando, Auteur ; P. Aragonés-Beltrán, Auteur ; A. Hospitaler-Pérez, Auteur . - 2011 . - pp. 905–916. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 905–916 Mots-clés : Multiple  criteria  decision  analysis  Analytic  network  process  (ANP)  Analytic  hierarchy  process  (AHP)  Public  works  bidding  Criteria  weighting Index. décimale : 001.424 Résumé : When the bidding conditions for a new public works contract are officially published, the contracting authority should count with objective criteria and weights to evaluate tenders. The evaluation criteria and weights are obtained from official contract documents. In this paper a new approach for the selection and measurement of the bidding criteria based on Analytic Hierarchy Processes (AHP) and Analytic Network Processes (ANP) is proposed. A hierarchy model and a 21-criterion network model have been developed and applied to two real cases: the first one is devoted to study the public bidding for the construction of an educational centre at the Polytechnic University of Valencia, whereas the second one analyses the public bidding for the remodelling and improvement of one section of a national road. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201013a.html

Investment evaluation within project management: an information systems perspective / Z. Irani in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 917–928 Titre : Investment evaluation within project management: an information systems perspective Type de document : texte imprimé Auteurs : Z. Irani, Auteur Année de publication : 2011 Article en page(s) : pp. 917–928 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Project  management  Evaluation  Information  systems Index. décimale : 001.424 Résumé : This paper is seeking to make a contribution through exploring project management from the perspective of information systems (IS) investment evaluation. Organizational investments in IS are significant in financial terms and, as a result, management would appear set to increasingly scrutinize such expenditure through tighter forms of decision-making and corporate governance. In turn, this has increased the motivation of project managers to appropriately evaluate the impact of their IS before, during and after the investments are signed off. This perspective is not restricted to any one industry sector, with the author seeking motivation for a better understanding of investment evaluation within a project management context. This paper sets out to explain why and how investment evaluation should be embedded in project management in order to support an increase in the effectiveness of project management, thereby increasing the prospects of project success. While doing so, the reader will be provided with several touch-points that serve to outline the purpose and challenges facing those seeking to evaluate their investments. The author starts off with a contextualization of project management and its phased activities, such that a clear understanding of the contribution that investment evaluation plays within robust project management can be demonstrated. Then, the perspective of investment versus consumption is presented, grounded within the strategic grid, which classifies information technology-based projects as either: strategic, turnaround, factory or support. The author then presents evaluation as a life-cycle process, where evaluation is classified into four distinctive phases, namely ex-ante evaluation, metrics, command and control and ex-post evaluation, in doing so, emphasizing that evaluation needs to be seen as a process that runs through the life cycle of a project rather than as a hurdle that needs to be cleared to ensure financial approval. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201010a.html [article] Investment evaluation within project management: an information systems perspective [texte imprimé] / Z. Irani, Auteur . - 2011 . - pp. 917–928. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 917–928 Mots-clés : Project  management  Evaluation  Information  systems Index. décimale : 001.424 Résumé : This paper is seeking to make a contribution through exploring project management from the perspective of information systems (IS) investment evaluation. Organizational investments in IS are significant in financial terms and, as a result, management would appear set to increasingly scrutinize such expenditure through tighter forms of decision-making and corporate governance. In turn, this has increased the motivation of project managers to appropriately evaluate the impact of their IS before, during and after the investments are signed off. This perspective is not restricted to any one industry sector, with the author seeking motivation for a better understanding of investment evaluation within a project management context. This paper sets out to explain why and how investment evaluation should be embedded in project management in order to support an increase in the effectiveness of project management, thereby increasing the prospects of project success. While doing so, the reader will be provided with several touch-points that serve to outline the purpose and challenges facing those seeking to evaluate their investments. The author starts off with a contextualization of project management and its phased activities, such that a clear understanding of the contribution that investment evaluation plays within robust project management can be demonstrated. Then, the perspective of investment versus consumption is presented, grounded within the strategic grid, which classifies information technology-based projects as either: strategic, turnaround, factory or support. The author then presents evaluation as a life-cycle process, where evaluation is classified into four distinctive phases, namely ex-ante evaluation, metrics, command and control and ex-post evaluation, in doing so, emphasizing that evaluation needs to be seen as a process that runs through the life cycle of a project rather than as a hurdle that needs to be cleared to ensure financial approval. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201010a.html

Evaluating and modelling constructs for e-government decision making / A. M. Sharif in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 929–952 Titre : Evaluating and modelling constructs for e-government decision making Type de document : texte imprimé Auteurs : A. M. Sharif, Auteur ; Z. Irani, Auteur ; V. Weerakkoddy, Auteur Année de publication : 2011 Article en page(s) : pp. 929–952 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : E-government  Project  management  Information  systems  evaluation  Fuzzy  cognitive  mapping Index. décimale : 001.424 Résumé : It is now becoming increasingly well understood that the investment and evaluation of electronic government projects is determinant on a number of organisational, policymaking and decision-making factors, which are determining the success or failure of such endeavours. Given the increasing interest in the manner and methods by which public sector projects are implemented as well as evaluated, this paper attempts to synergise contemporary e-government project management (PM) components and synthesise these with extant principles of information systems evaluation. This is carried out in order to model and understand the underlying constructs and determinants of decision-making and operational dynamics within an electronic government case study. The authors seek to advance and apply the cognitive mapping technique of Fuzzy Cognitive Mapping (FCM), through the use of an interpretivist, empirical enquiry technique that is melded with an exploratory simulation of the key factors involved in e-government PM issues. The FCM allows the identification of the inter-relationships within this context and provides a basis for identifying those constructs of PM that drive the case study decision-making agenda. Correlative relationships are also highlighted alongside causal inter-relationships among the dynamic interacting nodes of the digraph representation, to fully explore the schema of project evaluation in e-government. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201011a.html [article] Evaluating and modelling constructs for e-government decision making [texte imprimé] / A. M. Sharif, Auteur ; Z. Irani, Auteur ; V. Weerakkoddy, Auteur . - 2011 . - pp. 929–952. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 929–952 Mots-clés : E-government  Project  management  Information  systems  evaluation  Fuzzy  cognitive  mapping Index. décimale : 001.424 Résumé : It is now becoming increasingly well understood that the investment and evaluation of electronic government projects is determinant on a number of organisational, policymaking and decision-making factors, which are determining the success or failure of such endeavours. Given the increasing interest in the manner and methods by which public sector projects are implemented as well as evaluated, this paper attempts to synergise contemporary e-government project management (PM) components and synthesise these with extant principles of information systems evaluation. This is carried out in order to model and understand the underlying constructs and determinants of decision-making and operational dynamics within an electronic government case study. The authors seek to advance and apply the cognitive mapping technique of Fuzzy Cognitive Mapping (FCM), through the use of an interpretivist, empirical enquiry technique that is melded with an exploratory simulation of the key factors involved in e-government PM issues. The FCM allows the identification of the inter-relationships within this context and provides a basis for identifying those constructs of PM that drive the case study decision-making agenda. Correlative relationships are also highlighted alongside causal inter-relationships among the dynamic interacting nodes of the digraph representation, to fully explore the schema of project evaluation in e-government. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors201011a.html

Synthesis as conception shifting / L. Houghton in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 953–963 Titre : Synthesis as conception shifting Type de document : texte imprimé Auteurs : L. Houghton, Auteur ; Metcalfe, M., Auteur Année de publication : 2011 Article en page(s) : pp. 953–963 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Synthesis  Systems  thinking  Shifting  concepts  Case  studies Index. décimale : 001.424 Résumé : John Dewey's work inspired Simon, Churchman and Ackoff. To encourage rigorous thinking, Dewey makes the rallying cry: Synthesize don't just analyse. Operational research does analysis well. However, our understanding of its conjoint twin, synthesis, may need some more pragmatic rationalization. Synthesis, often confused with systems thinking, is thought to be a process of engagement with alternative conceptions (interpretations) of the problem domain; conceptions that suggest a different solution set. Therefore, this paper explores the proposition that operational research needs to engage more synthesis to complement its skill at analysis. Why synthesis is required, what it is and how it works is explained. Two case studies are provided to demonstrate the mechanisms of synthesis as one part of strategic thinking. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors2008188a.html [article] Synthesis as conception shifting [texte imprimé] / L. Houghton, Auteur ; Metcalfe, M., Auteur . - 2011 . - pp. 953–963. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 953–963 Mots-clés : Synthesis  Systems  thinking  Shifting  concepts  Case  studies Index. décimale : 001.424 Résumé : John Dewey's work inspired Simon, Churchman and Ackoff. To encourage rigorous thinking, Dewey makes the rallying cry: Synthesize don't just analyse. Operational research does analysis well. However, our understanding of its conjoint twin, synthesis, may need some more pragmatic rationalization. Synthesis, often confused with systems thinking, is thought to be a process of engagement with alternative conceptions (interpretations) of the problem domain; conceptions that suggest a different solution set. Therefore, this paper explores the proposition that operational research needs to engage more synthesis to complement its skill at analysis. Why synthesis is required, what it is and how it works is explained. Two case studies are provided to demonstrate the mechanisms of synthesis as one part of strategic thinking. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors2008188a.html

Challenges of operations research practice in agricultural value chains / A. J. Higgins in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 964–973 Titre : Challenges of operations research practice in agricultural value chains Type de document : texte imprimé Auteurs : A. J. Higgins, Auteur ; C. J. Miller, Auteur ; A. A. Archer, Auteur Année de publication : 2011 Article en page(s) : pp. 964–973 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Agriculture  Practice  of  OR  Methodology  Complexity Index. décimale : 001.424 Résumé : Operations research (OR) methodologies in optimization have been extensively applied to problems in different agricultural value chains in recent years. We take a critical stock take of such applications to date, and reflect on their contribution to value chain sustainability and resilience. The stock take shows that the rate of industry or policy adoption has been limited, partly due to the complex interactions across the segments of agricultural value chains, and the mathematical representation being different to the way the decision maker understands the problem. OR practice in agriculture is also being asked to cover greater spatial scales and engage more stakeholders, and is required to embrace resilience and sustainability objectives. A single-minded focus on optimizing parts of these complex systems without considering the whole system is no longer adequate, and new methods and approaches are required. Complex systems science methods are being applied to analyse the dynamics of complex social–ecological systems, and are starting to find a home in industrial supply chain analysis. We demonstrate how three complex system methods, agent-based modelling, dynamical systems modelling and network analysis, can be applied to agricultural value chains as a means of gaining insights into system dynamics under different and dynamic conditions. The relevance and utility of OR in ensuring the success of agricultural value chains into the future will require practitioners to understand and model value chains as complex adaptive systems. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200957a.html [article] Challenges of operations research practice in agricultural value chains [texte imprimé] / A. J. Higgins, Auteur ; C. J. Miller, Auteur ; A. A. Archer, Auteur . - 2011 . - pp. 964–973. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 964–973 Mots-clés : Agriculture  Practice  of  OR  Methodology  Complexity Index. décimale : 001.424 Résumé : Operations research (OR) methodologies in optimization have been extensively applied to problems in different agricultural value chains in recent years. We take a critical stock take of such applications to date, and reflect on their contribution to value chain sustainability and resilience. The stock take shows that the rate of industry or policy adoption has been limited, partly due to the complex interactions across the segments of agricultural value chains, and the mathematical representation being different to the way the decision maker understands the problem. OR practice in agriculture is also being asked to cover greater spatial scales and engage more stakeholders, and is required to embrace resilience and sustainability objectives. A single-minded focus on optimizing parts of these complex systems without considering the whole system is no longer adequate, and new methods and approaches are required. Complex systems science methods are being applied to analyse the dynamics of complex social–ecological systems, and are starting to find a home in industrial supply chain analysis. We demonstrate how three complex system methods, agent-based modelling, dynamical systems modelling and network analysis, can be applied to agricultural value chains as a means of gaining insights into system dynamics under different and dynamic conditions. The relevance and utility of OR in ensuring the success of agricultural value chains into the future will require practitioners to understand and model value chains as complex adaptive systems. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200957a.html

Dynamic preventive maintenance scheduling of the modules of fighter aircraft based on random effects regression model / Sohn, S. Y. in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 974–979 Titre : Dynamic preventive maintenance scheduling of the modules of fighter aircraft based on random effects regression model Type de document : texte imprimé Auteurs : Sohn, S. Y., Auteur ; K. B. Yoon, Auteur Année de publication : 2011 Article en page(s) : pp. 974–979 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Dynamic  preventive  maintenance  Fighter  aircraft  Random  effects  Weibull-inverse  gamma  regression  model  MTBF  MTTR Index. décimale : 001.424 Résumé : Proper maintenance of fighter aircraft is an important issue to control the airpower. Typical maintenance policy applied is based on the constant schedule for a given module. This kind of maintenance does not take into account varying characteristics of the module over time. In this paper, we utilize the random effects Weibull regression model for non-constant MTBF (mean time between failure) and MTTR (mean time to repair) in order to provide a dynamic preventive maintenance schedule reflecting the module's varying characteristics in a timely manner. Our study is expected to contribute to ROKA (Republic of Korea Airforce) in terms of improving the level of combat readiness of fighter aircraft. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors2008167a.html [article] Dynamic preventive maintenance scheduling of the modules of fighter aircraft based on random effects regression model [texte imprimé] / Sohn, S. Y., Auteur ; K. B. Yoon, Auteur . - 2011 . - pp. 974–979. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 974–979 Mots-clés : Dynamic  preventive  maintenance  Fighter  aircraft  Random  effects  Weibull-inverse  gamma  regression  model  MTBF  MTTR Index. décimale : 001.424 Résumé : Proper maintenance of fighter aircraft is an important issue to control the airpower. Typical maintenance policy applied is based on the constant schedule for a given module. This kind of maintenance does not take into account varying characteristics of the module over time. In this paper, we utilize the random effects Weibull regression model for non-constant MTBF (mean time between failure) and MTTR (mean time to repair) in order to provide a dynamic preventive maintenance schedule reflecting the module's varying characteristics in a timely manner. Our study is expected to contribute to ROKA (Republic of Korea Airforce) in terms of improving the level of combat readiness of fighter aircraft. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors2008167a.html

Optimal batting orders in cricket / J. M. Norman in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 980–986 Titre : Optimal batting orders in cricket Type de document : texte imprimé Auteurs : J. M. Norman, Auteur ; Clarke, S. R., Auteur Année de publication : 2011 Article en page(s) : pp. 980–986 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Dynamic  programming  Sports  Cricket  Batting  order Index. décimale : 001.424 Résumé : Cricket teams are usually listed on the scoreboard in expected batting order, and although captains can choose to send in any of the remaining batsmen when a wicket falls, they rarely depart from the usual batting order. By optimizing a simplified model using dynamic programming, this paper shows that in all forms of cricket significant increases in expected score result if captains allow a variable batting order and base their decision on the state of the game, rather than using a set batting order. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200954a.html [article] Optimal batting orders in cricket [texte imprimé] / J. M. Norman, Auteur ; Clarke, S. R., Auteur . - 2011 . - pp. 980–986. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 980–986 Mots-clés : Dynamic  programming  Sports  Cricket  Batting  order Index. décimale : 001.424 Résumé : Cricket teams are usually listed on the scoreboard in expected batting order, and although captains can choose to send in any of the remaining batsmen when a wicket falls, they rarely depart from the usual batting order. By optimizing a simplified model using dynamic programming, this paper shows that in all forms of cricket significant increases in expected score result if captains allow a variable batting order and base their decision on the state of the game, rather than using a set batting order. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200954a.html

Location of single-server immobile facilities subject to a loss constraint / B. Boffey in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 987–999 Titre : Location of single-server immobile facilities subject to a loss constraint Type de document : texte imprimé Auteurs : B. Boffey, Auteur ; R. D. Galvão, Auteur ; V. Marianov, Auteur Année de publication : 2011 Article en page(s) : pp. 987–999 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Location  Queues  Loss  Erlang  distribution Index. décimale : 001.424 Résumé : Waiting may be unacceptable, even a short time, at a facility providing a service involving medical or other emergencies. Hence, it is appropriate to locate such facilities so that the rate at which users are lost is limited. Each facility will here be modelled as an M/Er/m/N queueing system subject to a loss restriction constraint and the single-server case (m=1) will be treated in detail. Introduction of the Erlang distribution for service times allows a better fit of the model to actual values of both mean and variance than do currently available models that use an exponential distribution. Location of facilities will be such that the average travel time to a facility is minimized. It is shown how a deterministic constraint, equivalent to the loss constraint, can be generated resulting in an integer linear program, and values of a parameter ρc which facilitates this linearization are tabulated for various values of r, N and service level demanded. Numerical experiments are performed including an application loosely related to the location of neonatal clinics in the Municipality of Rio de Janeiro. Finally, there is a discussion of how further improved modelling of the service time distribution might be effected. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200912a.html [article] Location of single-server immobile facilities subject to a loss constraint [texte imprimé] / B. Boffey, Auteur ; R. D. Galvão, Auteur ; V. Marianov, Auteur . - 2011 . - pp. 987–999. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 987–999 Mots-clés : Location  Queues  Loss  Erlang  distribution Index. décimale : 001.424 Résumé : Waiting may be unacceptable, even a short time, at a facility providing a service involving medical or other emergencies. Hence, it is appropriate to locate such facilities so that the rate at which users are lost is limited. Each facility will here be modelled as an M/Er/m/N queueing system subject to a loss restriction constraint and the single-server case (m=1) will be treated in detail. Introduction of the Erlang distribution for service times allows a better fit of the model to actual values of both mean and variance than do currently available models that use an exponential distribution. Location of facilities will be such that the average travel time to a facility is minimized. It is shown how a deterministic constraint, equivalent to the loss constraint, can be generated resulting in an integer linear program, and values of a parameter ρc which facilitates this linearization are tabulated for various values of r, N and service level demanded. Numerical experiments are performed including an application loosely related to the location of neonatal clinics in the Municipality of Rio de Janeiro. Finally, there is a discussion of how further improved modelling of the service time distribution might be effected. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200912a.html

Optimal placement, scheduling, and routing to maximize lifetime in sensor networks / Y. B. Türkoullari in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1000–1012 Titre : Optimal placement, scheduling, and routing to maximize lifetime in sensor networks Type de document : texte imprimé Auteurs : Y. B. Türkoullari, Auteur ; N. Aras, Auteur ; Altinel, I. K., Auteur Année de publication : 2011 Article en page(s) : pp. 1000–1012 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Sensor  networks  Heuristics  Integer  programming  Telecommunications Index. décimale : 001.424 Résumé : A wireless sensor network is a network consisting of distributed autonomous electronic devices called sensors. Sensors have limited energy and capability for sensing, data processing, and communicating, but they can collectively behave to provide an effective network that monitors an area and transmit information to gateway nodes or sinks, either directly or through other sensor nodes. In most applications the network must operate for long periods of time, so the available energy resources of the sensors must be managed efficiently. In this paper, we first develop a mixed integer linear programming model to maximize network lifetime by optimally determining locations of sensors and sinks, activity schedules of deployed sensors, and data flow routes from sensors to sinks over a finite planning horizon subject to coverage, flow conservation, energy consumption, and budget constraints. Unfortunately, it is difficult to solve this model exactly even for small instances. Therefore, we propose two approximate solution methods: a Lagrangean heuristic and a two-stage heuristic in which sensors are deployed and an activity schedule is found in the first stage, whereas sinks are located and sensor-to-sink data flow routes are determined in the second stage. Computational experiments performed on various test instances indicate that the Lagrangean heuristic is both efficient and accurate and also outperforms the two-stage heuristic. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors2008187a.html [article] Optimal placement, scheduling, and routing to maximize lifetime in sensor networks [texte imprimé] / Y. B. Türkoullari, Auteur ; N. Aras, Auteur ; Altinel, I. K., Auteur . - 2011 . - pp. 1000–1012. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1000–1012 Mots-clés : Sensor  networks  Heuristics  Integer  programming  Telecommunications Index. décimale : 001.424 Résumé : A wireless sensor network is a network consisting of distributed autonomous electronic devices called sensors. Sensors have limited energy and capability for sensing, data processing, and communicating, but they can collectively behave to provide an effective network that monitors an area and transmit information to gateway nodes or sinks, either directly or through other sensor nodes. In most applications the network must operate for long periods of time, so the available energy resources of the sensors must be managed efficiently. In this paper, we first develop a mixed integer linear programming model to maximize network lifetime by optimally determining locations of sensors and sinks, activity schedules of deployed sensors, and data flow routes from sensors to sinks over a finite planning horizon subject to coverage, flow conservation, energy consumption, and budget constraints. Unfortunately, it is difficult to solve this model exactly even for small instances. Therefore, we propose two approximate solution methods: a Lagrangean heuristic and a two-stage heuristic in which sensors are deployed and an activity schedule is found in the first stage, whereas sinks are located and sensor-to-sink data flow routes are determined in the second stage. Computational experiments performed on various test instances indicate that the Lagrangean heuristic is both efficient and accurate and also outperforms the two-stage heuristic. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors2008187a.html

Solving the forward-reserve allocation problem in warehouse order picking systems / J. Gu in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1013–1021 Titre : Solving the forward-reserve allocation problem in warehouse order picking systems Type de document : texte imprimé Auteurs : J. Gu, Auteur ; M. Goetschalckx, Auteur ; L. F. McGinnis, Auteur Année de publication : 2011 Article en page(s) : pp. 1013–1021 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Warehousing  Forward-reserve  warehouse  Order  picking  Branch-and-bound  algorithm Index. décimale : 001.424 Résumé : Many warehouses store at least some goods in two areas, a reserve area that is efficient for storage and a forward area that is efficient for order picking. The forward-reserve allocation problem determines the set of Stock-Keeping Units and their space allocations in the forward area to maximize the forward area's benefit by trading off the relevant costs of order picking and internal replenishment. The mathematical model of this decision resembles the classical knapsack problem with the additional complexity that it has a discontinuous nonlinear cost function. A simple greedy heuristic has been proposed in the literature to solve this problem. This paper proposes an alternative branch-and-bound algorithm that can quickly solve the problem to optimality. Heuristic and optimal solutions are numerically compared using problem instances based on real warehouse data. Results suggest that the heuristic solutions are very close to the optimal ones in terms of both the objective value and the forward assignment. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200939a.html [article] Solving the forward-reserve allocation problem in warehouse order picking systems [texte imprimé] / J. Gu, Auteur ; M. Goetschalckx, Auteur ; L. F. McGinnis, Auteur . - 2011 . - pp. 1013–1021. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1013–1021 Mots-clés : Warehousing  Forward-reserve  warehouse  Order  picking  Branch-and-bound  algorithm Index. décimale : 001.424 Résumé : Many warehouses store at least some goods in two areas, a reserve area that is efficient for storage and a forward area that is efficient for order picking. The forward-reserve allocation problem determines the set of Stock-Keeping Units and their space allocations in the forward area to maximize the forward area's benefit by trading off the relevant costs of order picking and internal replenishment. The mathematical model of this decision resembles the classical knapsack problem with the additional complexity that it has a discontinuous nonlinear cost function. A simple greedy heuristic has been proposed in the literature to solve this problem. This paper proposes an alternative branch-and-bound algorithm that can quickly solve the problem to optimality. Heuristic and optimal solutions are numerically compared using problem instances based on real warehouse data. Results suggest that the heuristic solutions are very close to the optimal ones in terms of both the objective value and the forward assignment. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200939a.html

The newsvendor problem with unknown distribution / U. Benzion in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1022–1031 Titre : The newsvendor problem with unknown distribution Type de document : texte imprimé Auteurs : U. Benzion, Auteur ; Y. Cohen, Auteur ; T. Shavit, Auteur Année de publication : 2011 Article en page(s) : pp. 1022–1031 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Behavioural  operation  Newsvendor  problem  Learning  Demand  distribution  Purchase  decision Index. décimale : 001.424 Résumé : Newsvendor theory assumes that the decision-maker faces a known distribution. But in real-life situations, demand distribution is not always known. In the experimental study which this paper presents, half of the participants assuming the newsvendor role were unaware of the underlying demand distribution, while the other half knew the demand distribution. Participants had to decide how many papers to order each day (for 100 days). The experimental findings indicate that subjects who know the demand distribution behave differently to those who do not. However, interestingly enough, knowing the demand distribution does not necessarily lead the subject closer to the optimal solution or improve profits. It was found that supply surplus at a certain period strongly affects the order quantity towards the following period, despite the knowledge of the demand distribution. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200956a.html [article] The newsvendor problem with unknown distribution [texte imprimé] / U. Benzion, Auteur ; Y. Cohen, Auteur ; T. Shavit, Auteur . - 2011 . - pp. 1022–1031. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1022–1031 Mots-clés : Behavioural  operation  Newsvendor  problem  Learning  Demand  distribution  Purchase  decision Index. décimale : 001.424 Résumé : Newsvendor theory assumes that the decision-maker faces a known distribution. But in real-life situations, demand distribution is not always known. In the experimental study which this paper presents, half of the participants assuming the newsvendor role were unaware of the underlying demand distribution, while the other half knew the demand distribution. Participants had to decide how many papers to order each day (for 100 days). The experimental findings indicate that subjects who know the demand distribution behave differently to those who do not. However, interestingly enough, knowing the demand distribution does not necessarily lead the subject closer to the optimal solution or improve profits. It was found that supply surplus at a certain period strongly affects the order quantity towards the following period, despite the knowledge of the demand distribution. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200956a.html

New heuristics for flow shop problem to minimize makespan / D. Bai in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1032–1040 Titre : New heuristics for flow shop problem to minimize makespan Type de document : texte imprimé Auteurs : D. Bai, Auteur ; Tang, L., Auteur Année de publication : 2011 Article en page(s) : pp. 1032–1040 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Scheduling  Flow  shop  problem  Makespan  Performance  analysis  of  algorithm Index. décimale : 001.424 Résumé : This paper investigates the flow shop problem with the objective to minimize makespan. New algorithms are designed: one is off-line heuristic, Single Job First, for problem Fm∥Cmax; and the other is on-line heuristic, Dynamic Single Job First (DSJF), for problem Fm|ri|Cmax and its on-line version. It is proved that the two heuristics are asymptotically optimal when the size of the problem is large enough. In addition, the asymptotical optimality of First-Come, First-Served manner is obtained as a byproduct of the asymptotical analysis of DSJF heuristic. At the end of the paper, a new lower bound with performance guarantee is provided for problem Fm∥Cmax, and computational experiments show the effectiveness of these heuristic algorithms. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200944a.html [article] New heuristics for flow shop problem to minimize makespan [texte imprimé] / D. Bai, Auteur ; Tang, L., Auteur . - 2011 . - pp. 1032–1040. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1032–1040 Mots-clés : Scheduling  Flow  shop  problem  Makespan  Performance  analysis  of  algorithm Index. décimale : 001.424 Résumé : This paper investigates the flow shop problem with the objective to minimize makespan. New algorithms are designed: one is off-line heuristic, Single Job First, for problem Fm∥Cmax; and the other is on-line heuristic, Dynamic Single Job First (DSJF), for problem Fm|ri|Cmax and its on-line version. It is proved that the two heuristics are asymptotically optimal when the size of the problem is large enough. In addition, the asymptotical optimality of First-Come, First-Served manner is obtained as a byproduct of the asymptotical analysis of DSJF heuristic. At the end of the paper, a new lower bound with performance guarantee is provided for problem Fm∥Cmax, and computational experiments show the effectiveness of these heuristic algorithms. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200944a.html

Scheduling jobs under an aging effect / A. Janiak in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1041–1048 Titre : Scheduling jobs under an aging effect Type de document : texte imprimé Auteurs : A. Janiak, Auteur ; R. Rudek, Auteur Année de publication : 2011 Article en page(s) : pp. 1041–1048 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Scheduling  Aging  effect  Deterioration  Computational  analysis Index. décimale : 001.424 Résumé : In this paper a scheduling problem that takes into consideration a phenomenon called ‘aging effect’ with reference to Computer Numerical Control drilling or cutting machines is investigated. In the aftermath of this effect an execution of jobs leads to a deterioration of a machine; thus processing times of jobs increase and the production facility becomes less efficient. However, it is highly desirable to minimize the negative influence of this effect. In general, it can be done by formulating such a problem in the scheduling context and optimizing an order of jobs to minimize the given criterion. Therefore, on this basis a makespan minimization problem on a single machine with release dates and the aging effect is formulated, where the job processing times are described by non-decreasing functions dependent on fatigue (wear) of machine. It is proved that even the special cases of the problem are NP-hard. Moreover, some problems equivalences are shown and polynomially solvable cases are also provided. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200930a.html [article] Scheduling jobs under an aging effect [texte imprimé] / A. Janiak, Auteur ; R. Rudek, Auteur . - 2011 . - pp. 1041–1048. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1041–1048 Mots-clés : Scheduling  Aging  effect  Deterioration  Computational  analysis Index. décimale : 001.424 Résumé : In this paper a scheduling problem that takes into consideration a phenomenon called ‘aging effect’ with reference to Computer Numerical Control drilling or cutting machines is investigated. In the aftermath of this effect an execution of jobs leads to a deterioration of a machine; thus processing times of jobs increase and the production facility becomes less efficient. However, it is highly desirable to minimize the negative influence of this effect. In general, it can be done by formulating such a problem in the scheduling context and optimizing an order of jobs to minimize the given criterion. Therefore, on this basis a makespan minimization problem on a single machine with release dates and the aging effect is formulated, where the job processing times are described by non-decreasing functions dependent on fatigue (wear) of machine. It is proved that even the special cases of the problem are NP-hard. Moreover, some problems equivalences are shown and polynomially solvable cases are also provided. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200930a.html

Correlation when data are missing / M. Parzen in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1049–1056 Titre : Correlation when data are missing Type de document : texte imprimé Auteurs : M. Parzen, Auteur ; S. Lipsitz, Auteur ; R. Metters, Auteur Année de publication : 2011 Article en page(s) : pp. 1049–1056 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Statistics  Methodology  Probability Index. décimale : 001.424 Résumé : Variable correlation is important for many operations research models. Many inventory, revenue management, and queuing models presume uncorrelated demand between products, market segments, or time periods. The specific model applied, or the resulting policies of a model, can differ drastically depending on variable correlation. Having missing data are a common problem for the real world application of operations research models. This work is at the junction of the two topics of correlation and missing data. We propose a test of independence between two variables when data are missing. The typical method for determining correlation with missing data ignores all data pairs in which one point is missing. The test presented here incorporates all data. The test can be applied when both variables are continuous, when both are discrete, or when one variable is discrete and the other is continuous. The test makes no assumptions about the distribution of the two variables, and thus it can be used to extend application of non-parametric rank tests, such as Spearman's rank correlation, to the case where data are missing. An example is shown where failure to incorporate the incomplete data yields incorrect policies. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200949a.html [article] Correlation when data are missing [texte imprimé] / M. Parzen, Auteur ; S. Lipsitz, Auteur ; R. Metters, Auteur . - 2011 . - pp. 1049–1056. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1049–1056 Mots-clés : Statistics  Methodology  Probability Index. décimale : 001.424 Résumé : Variable correlation is important for many operations research models. Many inventory, revenue management, and queuing models presume uncorrelated demand between products, market segments, or time periods. The specific model applied, or the resulting policies of a model, can differ drastically depending on variable correlation. Having missing data are a common problem for the real world application of operations research models. This work is at the junction of the two topics of correlation and missing data. We propose a test of independence between two variables when data are missing. The typical method for determining correlation with missing data ignores all data pairs in which one point is missing. The test presented here incorporates all data. The test can be applied when both variables are continuous, when both are discrete, or when one variable is discrete and the other is continuous. The test makes no assumptions about the distribution of the two variables, and thus it can be used to extend application of non-parametric rank tests, such as Spearman's rank correlation, to the case where data are missing. An example is shown where failure to incorporate the incomplete data yields incorrect policies. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200949a.html

A stylized model of ‘Momentum’ processes / S. Bandyopadhyay in Journal of the operational research society (JORS), Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1057–1062 Titre : A stylized model of ‘Momentum’ processes : a research note Type de document : texte imprimé Auteurs : S. Bandyopadhyay, Auteur Année de publication : 2011 Article en page(s) : pp. 1057–1062 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Momentum  processes  Correlated  random  walk  Quasi-birth-death  process  Transient  analysis Index. décimale : 001.424 Résumé : Several phenomena of interest like stock price movements, online auction bid prices or inventory levels, can be stylized as ‘momentum processes’, whereby the very start of activity (‘up’ or ‘down’) can trigger subsequent activity in that direction. We calculate the transient probabilities of being in a particular state (eg, stock price or current auction bid level) in such activities. The calculations can be used to estimate the expected time to reach a certain price, inventory level or bid. The processes can be modified to show the phenomenon where the lack of activity can have an ‘inertia of rest’. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200946a.html [article] A stylized model of ‘Momentum’ processes : a research note [texte imprimé] / S. Bandyopadhyay, Auteur . - 2011 . - pp. 1057–1062. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 6 (Juin 2010) . - pp. 1057–1062 Mots-clés : Momentum  processes  Correlated  random  walk  Quasi-birth-death  process  Transient  analysis Index. décimale : 001.424 Résumé : Several phenomena of interest like stock price movements, online auction bid prices or inventory levels, can be stylized as ‘momentum processes’, whereby the very start of activity (‘up’ or ‘down’) can trigger subsequent activity in that direction. We calculate the transient probabilities of being in a particular state (eg, stock price or current auction bid level) in such activities. The calculations can be used to estimate the expected time to reach a certain price, inventory level or bid. The processes can be modified to show the phenomenon where the lack of activity can have an ‘inertia of rest’. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n6/abs/jors200946a.html

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