The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

Soren Johansen - One of the best experts on this subject based on the ideXlab platform.

  • optimal and near optimal policies for lost sales inventory models with at most one replenishment order outstanding
    European Journal of Operational Research, 2006
    Co-Authors: Roger M Hill, Soren Johansen
    Abstract:

    In this paper we use policy-iteration to explore the behaviour of optimal control policies for lost sales inventory models with the constraint that not more than one replenishment order may be outstanding at any time. Continuous and periodic review, fixed and variable lead times, replenishment order sizes which are constrained to be an integral multiple of some fixed unit of transfer and service level constraint models are all Considered. Demand is discrete and, for continuous review, assumed to derive from a compound Poisson process. It is demonstrated that, in general, neither the best (s, S) nor the best (r, Q) policy is optimal but that the best policy from within those classes will have a cost which is generally close to that of the optimal policy obtained by policy iteration. Finally, near-optimal computationally-efficient control procedures for finding (s, S) and (r, Q) policies are proposed and their performance illustrated.

  • production manufacturing and logistics optimal and near optimal policies for lost sales inventory models with at most one replenishment order outstanding
    2006
    Co-Authors: Roger M Hill, Soren Johansen
    Abstract:

    In this paper we use policy-iteration to explore the behaviour of optimal control policies for lost sales inventory models with the constraint that not more than one replenishment order may be outstanding at any time. Continuous and periodic review, fixed and variable lead times, replenishment order sizes which are constrained to be an integral multiple of some fixed unit of transfer and service level constraint models are all Considered. Demand is discrete and, for continuous review, assumed to derive from a compound Poisson process. It is demonstrated that, in general, neither the best (s, S) nor the best (r, Q) policy is optimal but that the best policy from within those classes will have a cost which is generally close to that of the optimal policy obtained by policy iteration. Finally, near-optimal computationally-efficient control procedures for finding (s, S) and (r, Q) policies are proposed and their performance illustrated.

Michel Dumondel - One of the best experts on this subject based on the ideXlab platform.

  • On the link between economic and environmental performance of Swiss dairy farms of the alpine area
    The International Journal of Life Cycle Assessment, 2012
    Co-Authors: Markus Lips, Martina Alig, Michel Dumondel
    Abstract:

    Purpose Promoting the economic and environmental performance of Swiss farms is a major objective of Swiss agricultural policy. In the present paper, we investigate the relationship between the economic and global environmental performance of the Swiss dairy farms in the alpine area. Methods The analysis relies on a sample of 56 dairy farms from the Farm Accountancy Data Network, for which highly precise and comprehensive Life Cycle Assessments have been carried out. The work income per family work unit is used as indicator of the economic performance of a farm. The so-called global environmental performance of a farm is, for its part, measured by means of an eco-efficiency indicator for each environmental impact Considered (Demand for non-renewable energy resources, eutrophication potential, aquatic ecotoxicity potential, human toxicity potential and land use) and of an aggregate eco-efficiency indicator assessed using a Data Envelopment Analysis-based approach. The relationship between economic and global environmental performance is assessed by means of non-parametric Spearman’s rank correlation analysis. Results The results of the analysis reveal the existence of a positive relationship between economic and global environmental performance. This positive relationship exists for all environmental issues Considered and thus also for the aggregate eco-efficiency indicator. Its strength, however, substantially varies from one issue to another. Conclusions This study provides the evidence that there is no trade-off between economic and global environmental farm performance. When they improve their economic performance, farms also tend to improve their global environmental performance and vice versa. This finding is of central relevance for policy-makers as it should contribute to improving the acceptance among farmers of the environmental objectives of Swiss agricultural policy in terms of an increase in environmental resource use productivity. In this sense this work provides valuable insights into the sustainable performance of the Swiss dairy sector in the alpine area.

  • On the link between economic and environmental performance of Swiss dairy farms of the alpine area
    International Journal of Life Cycle Assessment, 2012
    Co-Authors: Markus Lips, Martina Alig, Michel Dumondel
    Abstract:

    Promoting the economic and environmental performance of Swiss farms is a major objective of Swiss agricultural policy. In the present paper, we investigate the relationship between the economic and global environmental performance of the Swiss dairy farms in the alpine area. The analysis relies on a sample of 56 dairy farms from the Farm Accountancy Data Network, for which highly precise and comprehensive Life Cycle Assessments have been carried out. The work income per family work unit is used as indicator of the economic performance of a farm. The so-called global environmental performance of a farm is, for its part, measured by means of an eco-efficiency indicator for each environmental impact Considered (Demand for non-renewable energy resources, eutrophication potential, aquatic ecotoxicity potential, human toxicity potential and land use) and of an aggregate eco-efficiency indicator assessed using a Data Envelopment Analysis-based approach. The relationship between economic and global environmental performance is assessed by means of non-parametric Spearman’s rank correlation analysis. The results of the analysis reveal the existence of a positive relationship between economic and global environmental performance. This positive relationship exists for all environmental issues Considered and thus also for the aggregate eco-efficiency indicator. Its strength, however, substantially varies from one issue to another. This study provides the evidence that there is no trade-off between economic and global environmental farm performance. When they improve their economic performance, farms also tend to improve their global environmental performance and vice versa. This finding is of central relevance for policy-makers as it should contribute to improving the acceptance among farmers of the environmental objectives of Swiss agricultural policy in terms of an increase in environmental resource use productivity. In this sense this work provides valuable insights into the sustainable performance of the Swiss dairy sector in the alpine area.

Roger M Hill - One of the best experts on this subject based on the ideXlab platform.

  • optimal and near optimal policies for lost sales inventory models with at most one replenishment order outstanding
    European Journal of Operational Research, 2006
    Co-Authors: Roger M Hill, Soren Johansen
    Abstract:

    In this paper we use policy-iteration to explore the behaviour of optimal control policies for lost sales inventory models with the constraint that not more than one replenishment order may be outstanding at any time. Continuous and periodic review, fixed and variable lead times, replenishment order sizes which are constrained to be an integral multiple of some fixed unit of transfer and service level constraint models are all Considered. Demand is discrete and, for continuous review, assumed to derive from a compound Poisson process. It is demonstrated that, in general, neither the best (s, S) nor the best (r, Q) policy is optimal but that the best policy from within those classes will have a cost which is generally close to that of the optimal policy obtained by policy iteration. Finally, near-optimal computationally-efficient control procedures for finding (s, S) and (r, Q) policies are proposed and their performance illustrated.

  • production manufacturing and logistics optimal and near optimal policies for lost sales inventory models with at most one replenishment order outstanding
    2006
    Co-Authors: Roger M Hill, Soren Johansen
    Abstract:

    In this paper we use policy-iteration to explore the behaviour of optimal control policies for lost sales inventory models with the constraint that not more than one replenishment order may be outstanding at any time. Continuous and periodic review, fixed and variable lead times, replenishment order sizes which are constrained to be an integral multiple of some fixed unit of transfer and service level constraint models are all Considered. Demand is discrete and, for continuous review, assumed to derive from a compound Poisson process. It is demonstrated that, in general, neither the best (s, S) nor the best (r, Q) policy is optimal but that the best policy from within those classes will have a cost which is generally close to that of the optimal policy obtained by policy iteration. Finally, near-optimal computationally-efficient control procedures for finding (s, S) and (r, Q) policies are proposed and their performance illustrated.

Markus Lips - One of the best experts on this subject based on the ideXlab platform.

  • On the link between economic and environmental performance of Swiss dairy farms of the alpine area
    The International Journal of Life Cycle Assessment, 2012
    Co-Authors: Markus Lips, Martina Alig, Michel Dumondel
    Abstract:

    Purpose Promoting the economic and environmental performance of Swiss farms is a major objective of Swiss agricultural policy. In the present paper, we investigate the relationship between the economic and global environmental performance of the Swiss dairy farms in the alpine area. Methods The analysis relies on a sample of 56 dairy farms from the Farm Accountancy Data Network, for which highly precise and comprehensive Life Cycle Assessments have been carried out. The work income per family work unit is used as indicator of the economic performance of a farm. The so-called global environmental performance of a farm is, for its part, measured by means of an eco-efficiency indicator for each environmental impact Considered (Demand for non-renewable energy resources, eutrophication potential, aquatic ecotoxicity potential, human toxicity potential and land use) and of an aggregate eco-efficiency indicator assessed using a Data Envelopment Analysis-based approach. The relationship between economic and global environmental performance is assessed by means of non-parametric Spearman’s rank correlation analysis. Results The results of the analysis reveal the existence of a positive relationship between economic and global environmental performance. This positive relationship exists for all environmental issues Considered and thus also for the aggregate eco-efficiency indicator. Its strength, however, substantially varies from one issue to another. Conclusions This study provides the evidence that there is no trade-off between economic and global environmental farm performance. When they improve their economic performance, farms also tend to improve their global environmental performance and vice versa. This finding is of central relevance for policy-makers as it should contribute to improving the acceptance among farmers of the environmental objectives of Swiss agricultural policy in terms of an increase in environmental resource use productivity. In this sense this work provides valuable insights into the sustainable performance of the Swiss dairy sector in the alpine area.

  • On the link between economic and environmental performance of Swiss dairy farms of the alpine area
    International Journal of Life Cycle Assessment, 2012
    Co-Authors: Markus Lips, Martina Alig, Michel Dumondel
    Abstract:

    Promoting the economic and environmental performance of Swiss farms is a major objective of Swiss agricultural policy. In the present paper, we investigate the relationship between the economic and global environmental performance of the Swiss dairy farms in the alpine area. The analysis relies on a sample of 56 dairy farms from the Farm Accountancy Data Network, for which highly precise and comprehensive Life Cycle Assessments have been carried out. The work income per family work unit is used as indicator of the economic performance of a farm. The so-called global environmental performance of a farm is, for its part, measured by means of an eco-efficiency indicator for each environmental impact Considered (Demand for non-renewable energy resources, eutrophication potential, aquatic ecotoxicity potential, human toxicity potential and land use) and of an aggregate eco-efficiency indicator assessed using a Data Envelopment Analysis-based approach. The relationship between economic and global environmental performance is assessed by means of non-parametric Spearman’s rank correlation analysis. The results of the analysis reveal the existence of a positive relationship between economic and global environmental performance. This positive relationship exists for all environmental issues Considered and thus also for the aggregate eco-efficiency indicator. Its strength, however, substantially varies from one issue to another. This study provides the evidence that there is no trade-off between economic and global environmental farm performance. When they improve their economic performance, farms also tend to improve their global environmental performance and vice versa. This finding is of central relevance for policy-makers as it should contribute to improving the acceptance among farmers of the environmental objectives of Swiss agricultural policy in terms of an increase in environmental resource use productivity. In this sense this work provides valuable insights into the sustainable performance of the Swiss dairy sector in the alpine area.

Martina Alig - One of the best experts on this subject based on the ideXlab platform.

  • On the link between economic and environmental performance of Swiss dairy farms of the alpine area
    The International Journal of Life Cycle Assessment, 2012
    Co-Authors: Markus Lips, Martina Alig, Michel Dumondel
    Abstract:

    Purpose Promoting the economic and environmental performance of Swiss farms is a major objective of Swiss agricultural policy. In the present paper, we investigate the relationship between the economic and global environmental performance of the Swiss dairy farms in the alpine area. Methods The analysis relies on a sample of 56 dairy farms from the Farm Accountancy Data Network, for which highly precise and comprehensive Life Cycle Assessments have been carried out. The work income per family work unit is used as indicator of the economic performance of a farm. The so-called global environmental performance of a farm is, for its part, measured by means of an eco-efficiency indicator for each environmental impact Considered (Demand for non-renewable energy resources, eutrophication potential, aquatic ecotoxicity potential, human toxicity potential and land use) and of an aggregate eco-efficiency indicator assessed using a Data Envelopment Analysis-based approach. The relationship between economic and global environmental performance is assessed by means of non-parametric Spearman’s rank correlation analysis. Results The results of the analysis reveal the existence of a positive relationship between economic and global environmental performance. This positive relationship exists for all environmental issues Considered and thus also for the aggregate eco-efficiency indicator. Its strength, however, substantially varies from one issue to another. Conclusions This study provides the evidence that there is no trade-off between economic and global environmental farm performance. When they improve their economic performance, farms also tend to improve their global environmental performance and vice versa. This finding is of central relevance for policy-makers as it should contribute to improving the acceptance among farmers of the environmental objectives of Swiss agricultural policy in terms of an increase in environmental resource use productivity. In this sense this work provides valuable insights into the sustainable performance of the Swiss dairy sector in the alpine area.

  • On the link between economic and environmental performance of Swiss dairy farms of the alpine area
    International Journal of Life Cycle Assessment, 2012
    Co-Authors: Markus Lips, Martina Alig, Michel Dumondel
    Abstract:

    Promoting the economic and environmental performance of Swiss farms is a major objective of Swiss agricultural policy. In the present paper, we investigate the relationship between the economic and global environmental performance of the Swiss dairy farms in the alpine area. The analysis relies on a sample of 56 dairy farms from the Farm Accountancy Data Network, for which highly precise and comprehensive Life Cycle Assessments have been carried out. The work income per family work unit is used as indicator of the economic performance of a farm. The so-called global environmental performance of a farm is, for its part, measured by means of an eco-efficiency indicator for each environmental impact Considered (Demand for non-renewable energy resources, eutrophication potential, aquatic ecotoxicity potential, human toxicity potential and land use) and of an aggregate eco-efficiency indicator assessed using a Data Envelopment Analysis-based approach. The relationship between economic and global environmental performance is assessed by means of non-parametric Spearman’s rank correlation analysis. The results of the analysis reveal the existence of a positive relationship between economic and global environmental performance. This positive relationship exists for all environmental issues Considered and thus also for the aggregate eco-efficiency indicator. Its strength, however, substantially varies from one issue to another. This study provides the evidence that there is no trade-off between economic and global environmental farm performance. When they improve their economic performance, farms also tend to improve their global environmental performance and vice versa. This finding is of central relevance for policy-makers as it should contribute to improving the acceptance among farmers of the environmental objectives of Swiss agricultural policy in terms of an increase in environmental resource use productivity. In this sense this work provides valuable insights into the sustainable performance of the Swiss dairy sector in the alpine area.