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Berling, Peter
Publications (10 of 21) Show all publications
Berling, P. & Eng-Larsson, F. (2017). Environmental implications of transport contract choice - capacity investment and pricing under volume and capacity contracts. European Journal of Operational Research, 261(1), 129-142
Open this publication in new window or tab >>Environmental implications of transport contract choice - capacity investment and pricing under volume and capacity contracts
2017 (English)In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 261, no 1, p. 129-142Article in journal (Refereed) Published
Abstract [en]

Inspired by the observation that capacity contracts are used by some retailers to increase their transport provider's investments in green transport solutions, we investigate and compare a service provider's optimal investment, and its environmental implications under a volume and a capacity contract respectively. We solve the service provider's investment problem under the assumption that the retailer uses the service to replenish a warehouse with storable goods. We then show that a capacity contract leads to more green transports, but not necessarily a larger investment in green transport solutions. At the same time, the optimal solution involves heavy investment in inventory at the retailer. The investment in inventory is non-decreasing in the cost benefit of the green transports, which may have a significant negative environmental impact. The implication is that a capacity contract will lead to better environmental performance than a volume contract only when the green transports' cost benefit is within a given interval. Whether the capacity contract is the more profitable option for the service provider within this interval depends on inventory related costs and the relative environmental costs from transportation and inventory. Interestingly, owing to this, regulation that target the price of the conventional vehicles, such as a carbon tax, may lead to both an increase or a decrease in environmental performance. (C) 2017 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Inventory, Green transports, OM and the environment, Contracting, Capacity contracts
National Category
Economics and Business Environmental Sciences
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-64425 (URN)10.1016/j.ejor.2017.01.056 (DOI)000400221000011 ()2-s2.0-85015308634 (Scopus ID)
Available from: 2017-05-29 Created: 2017-05-29 Last updated: 2019-08-29Bibliographically approved
Berling, P. & Marklund, J. (2017). Green Inventory Management (1ed.). In: Yann Bouchery, Charles J. Corbett, Jan C. Fransoo & Tarkan Tan (Ed.), Sustainable supply chains: a research-based textbook on operations and strategy (pp. 189-218). Springer
Open this publication in new window or tab >>Green Inventory Management
2017 (English)In: Sustainable supply chains: a research-based textbook on operations and strategy / [ed] Yann Bouchery, Charles J. Corbett, Jan C. Fransoo & Tarkan Tan, Springer, 2017, 1, p. 189-218Chapter in book (Refereed)
Abstract [en]

Managing inventories, and thereby material flows, is of key importance for achieving efficient and sustainable supply chains. Green inventory management is characterized by complementing the traditional economic (cost) focus with environmental (emissions) considerations. In this chapter we identify and discuss key questions and challenges for green inventory management research. We do so by categorizing the costs and emissions of operating an inventory system into those associated with: ordering and transporting items, holding items in stock, and not satisfying customer demand on time. A literature overview illustrates what issues have been addressed so far in this emerging field. We conclude that there is a promising potential for green inventory management practices to reduce both costs and emissions, but much remains to be done. Not least in terms of developing more general green inventory models for practical use.

Place, publisher, year, edition, pages
Springer, 2017 Edition: 1
Series
Springer Series in Supply Chain Management, ISSN 2365-6395 ; 4
National Category
Economics and Business
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-57311 (URN)10.1007/978-3-319-29791-0_8 (DOI)9783319297897 (ISBN)9783319297910 (ISBN)
Available from: 2016-10-07 Created: 2016-10-07 Last updated: 2016-11-07Bibliographically approved
Berling, P. & Martinez-de-Albeniz, V. (2016). A characterization of optimal base-stock levels for a multistage serial supply chain. Naval Research Logistics, 63(1), 32-46
Open this publication in new window or tab >>A characterization of optimal base-stock levels for a multistage serial supply chain
2016 (English)In: Naval Research Logistics, ISSN 0894-069X, E-ISSN 1520-6750, Vol. 63, no 1, p. 32-46Article in journal (Refereed) Published
Abstract [en]

In this article, we present a multistage model to optimize inventory control decisions under stochastic demand and continuous review. We first formulate the general problem for continuous stages and use a decomposition solution approach: since it is never optimal to let orders cross, the general problem can be broken into a set of single-unit subproblems that can be solved in a sequential fashion. These subproblems are optimal control problems for which a differential equation must be solved. This can be done easily by recursively identifying coefficients and performing a line search. The methodology is then extended to a discrete number of stages and allows us to compute the optimal solution in an efficient manner, with a competitive complexity. (c) 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 32-46, 2016

Keywords
unit decomposition, multi-echelon, inventory
National Category
Transport Systems and Logistics
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-52225 (URN)10.1002/nav.21675 (DOI)000373074400003 ()2-s2.0-84960460651 (Scopus ID)
Available from: 2016-04-25 Created: 2016-04-25 Last updated: 2017-11-30Bibliographically approved
Berling, P. & Martínez-de-Albéniz, V. (2016). Dynamic Speed Optimization in Supply Chains with Stochastic Demand. Transportation Science, 50(3), 1114-1127
Open this publication in new window or tab >>Dynamic Speed Optimization in Supply Chains with Stochastic Demand
2016 (English)In: Transportation Science, ISSN 0041-1655, E-ISSN 1526-5447, Vol. 50, no 3, p. 1114-1127Article in journal (Refereed) Published
Abstract [en]

In this paper, we analyze how to continuously adjust the speed in a supply chain with stochastic demand. For each unit (e.g., truckload, shipping container) in the chain, one must decide at which speed it should be moved downstream, given the state of the system, to minimize total supply chain costs. We decompose the problem into a set of one-dimensional subproblems that can be easily solved and characterize the optimal variable speed policy: under some assumptions, we show that it is optimal to set a speed that is first increasing in the distance to the market, and then decreasing. As a result, at optimality a given unit will experience an accelerating speed and then it will be slowed down, unless a demand occurs, in which case, the speed will be adjusted upward. We finally provide a transportation case study where we estimate the benefits of a variable-speed compared to a fixed-speed policy and show them to be significant both financially and from a CO2-emissions perspective.

Place, publisher, year, edition, pages
Institute for Operations Research and the Management Sciences (INFORMS), 2016
Keywords
variable speed, expediting, environmental impact
National Category
Business Administration
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-40550 (URN)10.1287/trsc.2014.0561 (DOI)
Available from: 2015-03-02 Created: 2015-03-02 Last updated: 2017-12-04Bibliographically approved
Jahre, M., Kembro, J., Rezvanian, T., Ergun, O., Håpnes, S. J. & Berling, P. (2016). Integrating supply chains for emergencies and ongoing operations in UNHCR. Journal of Operations Management, 45(Special Issue), 57-72
Open this publication in new window or tab >>Integrating supply chains for emergencies and ongoing operations in UNHCR
Show others...
2016 (English)In: Journal of Operations Management, ISSN 0272-6963, E-ISSN 1873-1317, Vol. 45, no Special Issue, p. 57-72Article in journal (Refereed) Published
Abstract [en]

Humanitarian organizations (HOs) often base their warehouse locations on individuals' experience and knowledge rather than on decision-support tools. Many HOs run separate supply chains for emergency response and ongoing operations. Based on reviews of humanitarian network design literature combined with an in-depth case study of United Nations High Commissioner for Refugees (UNHCR), this paper presents a warehouse location model for joint prepositioning that incorporates political and security situation factors. Although accessibility, co-location, security, and human resources are crucial to the practice of humanitarian operations management, such contextual factors have not been included in existing network optimization models before. We found that when quantified, and modeled, such factors are important determinants of network configuration. In addition, our results suggest that joint prepositioning for emergency response and ongoing operations allows for expansion of the global warehouse network, and reducing cost and response time.

Keywords
Facility location, Network configuration, Prepositioning, UNHCR
National Category
Transport Systems and Logistics Social Sciences Interdisciplinary
Research subject
Technology (byts ev till Engineering); Economy
Identifiers
urn:nbn:se:lnu:diva-56110 (URN)10.1016/j.jom.2016.05.009 (DOI)000382599100005 ()2-s2.0-84982190158 (Scopus ID)
Available from: 2016-09-08 Created: 2016-08-31 Last updated: 2018-01-10Bibliographically approved
Berling, P. & Eng-Larsson, F. (2016). Pricing and timing of consolidated deliveries in the presence of an express alternative: financial and environmental analysis. European Journal of Operational Research, 250(2), 590-601
Open this publication in new window or tab >>Pricing and timing of consolidated deliveries in the presence of an express alternative: financial and environmental analysis
2016 (English)In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 250, no 2, p. 590-601Article in journal (Refereed) Published
Abstract [en]

Shipment consolidation has been advocated by researchers and politicians as a means to reduce cost and improve environmental performance of logistics activities. This paper investigates consolidated transport solutions with a common shipment frequency. When a service provider designs such a solution for its customers, she faces a trade-off: to have the most time-sensitive customers join the consolidated solution, the frequency must be high, which makes it difficult to gather enough demand to reach the scale economies of the solution; but by not having the most time-sensitive customers join, there will be less demand per time unit, which also makes it difficult to reach the scale economies. In this paper we investigate the service provider’s pricing and timing problem and the environmental implications of the optimal policy. The service provider is responsible for multiple customers’ transports, and offers all customers two long-term contracts at two different prices: direct express delivery with immediate dispatch at full cost, or consolidated delivery at a given frequency at a reduced cost. It is shown that the optimal policy is largely driven by customer heterogeneity: limited heterogeneity in customers’ costs leads to very different optimal policies compared to large heterogeneity. We argue that the reason so many consolidation projects fail may be due to a strategic mismatch between heterogeneity and consolidation policy. We also show that even if the consolidated solution is implemented, it may lead to a larger environmental impact than direct deliveries due to inventory build-up or a higher-than-optimal frequency of the consolidated transport

Keywords
OR in environment and climate change, Shipment consolidation, Incentives, Supply chain management
National Category
Business Administration
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-47358 (URN)10.1016/j.ejor.2015.09.041 (DOI)000369196400021 ()2-s2.0-84954026078 (Scopus ID)
Available from: 2015-11-23 Created: 2015-11-23 Last updated: 2017-12-01Bibliographically approved
Berling, P. & Forslund, H. (Eds.). (2016). Proceedings från logistikföreningen Plans forsknings- och tillämpningskonferens. Paper presented at Logistikföreningen Plans forsknings- och tillämpningskonferens, Växjö, October 19-20, 2016. Växjö: Logistikföreningen Plan
Open this publication in new window or tab >>Proceedings från logistikföreningen Plans forsknings- och tillämpningskonferens
2016 (Swedish)Conference proceedings (editor) (Other academic)
Place, publisher, year, edition, pages
Växjö: Logistikföreningen Plan, 2016
National Category
Business Administration
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-60226 (URN)
Conference
Logistikföreningen Plans forsknings- och tillämpningskonferens, Växjö, October 19-20, 2016
Available from: 2017-01-25 Created: 2017-01-25 Last updated: 2017-02-06Bibliographically approved
Berling, P. & Xie, Z. (2014). Approximation algorithms for optimal purchase/inventory policy when purchase price and demand are stochastic. Or-Spektrum, 36(4), 1077-1095
Open this publication in new window or tab >>Approximation algorithms for optimal purchase/inventory policy when purchase price and demand are stochastic
2014 (English)In: Or-Spektrum, ISSN 0171-6468, E-ISSN 1436-6304, Vol. 36, no 4, p. 1077-1095Article in journal (Refereed) Published
Abstract [en]

We consider a purchase/inventory control problem in which the purchase price and demand are stochastic, a common situation encountered by firms that replenish in a foreign currency or from commodity markets. More specifically, we assume that the demand follows a Poisson arrival process and that the log-price evolves according to a general Wiener process. Under these circumstances, the optimal policy is a state dependent base-stock policy that can be described as a series of threshold prices. An iterative procedure for determining the optimal thresholds has been derived earlier but, even for the simplest price process, the solution quickly becomes numerically intractable. To deal with this, we propose an approximation that allows us to derive simple heuristics for finding thresholds that are close to optimal. For certain price processes the heuristics are just a series of closed-form expressions. The computational complexity is reduced significantly, and the numerical study shows that the new heuristics perform considerably better than earlier suggested heuristics.

Keywords
Stochastic purchase price, Inventory control, Approximation algorithms, Base-stock levels
National Category
Business Administration
Research subject
Economy, Ekonomistyrning
Identifiers
urn:nbn:se:lnu:diva-37914 (URN)10.1007/s00291-014-0369-4 (DOI)000342206700010 ()2-s2.0-84907686852 (Scopus ID)
Available from: 2014-10-30 Created: 2014-10-30 Last updated: 2017-12-05Bibliographically approved
Berling, P. & Farvid, M. (2014). Lead-time investigation and estimation in divergent supply chains. Paper presented at 17th International Symposium on Inventories, Budapest, Hungary, aug 2012. International Journal of Production Economics, 157(SI), 177-189
Open this publication in new window or tab >>Lead-time investigation and estimation in divergent supply chains
2014 (English)In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 157, no SI, p. 177-189Article in journal (Refereed) Published
Abstract [en]

This paper investigates the delay experienced by retailers in a distribution system due to shortages at the central warehouse. Simple formulae are developed to estimate the mean and variance of this delay. The formulae are based on replacing the stochastic lead-time demand with a stochastic demand rate, and they differ in how this demand rate is estimated. An extensive numerical study shows improved accuracy compared to existing methods with similar computational complexity. The numerical study also shows that the batch quantities and the service level have a large influence on the delay. Both the mean and variance of a retailer’s delay decrease with the service level and increase with the batch quantities used at the warehouse and at the retailer. No other variables seem to have a significant impact on the delay.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Lead-time, Stochastic, Inventory control, Multi echelon, (R, nQ)-policy
National Category
Transport Systems and Logistics
Research subject
Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-32597 (URN)10.1016/j.ijpe.2014.04.030 (DOI)000345734100020 ()2-s2.0-84922677015 (Scopus ID)
Conference
17th International Symposium on Inventories, Budapest, Hungary, aug 2012
Available from: 2014-03-04 Created: 2014-03-04 Last updated: 2017-12-05Bibliographically approved
Berling, P. & Marklund, J. (2014). Multi-echelon inventory control: an adjusted normal demand model for implementation in practice. International Journal of Production Research, 52(11), 3331-3347
Open this publication in new window or tab >>Multi-echelon inventory control: an adjusted normal demand model for implementation in practice
2014 (English)In: International Journal of Production Research, ISSN 0020-7543, E-ISSN 1366-588X, Vol. 52, no 11, p. 3331-3347Article in journal (Refereed) Published
Abstract [en]

This paper presents an approximation model for coordinated control of one-warehouse multiple-retailer inventory systems, where all locations use continuous review (RnQ) policies. The motivation stems from close collaboration with a supply chain management software company, Syncron International, and one of their customers. A core objective has been to develop an accurate method for determining near-optimal reorder points that can be directly applied to real-life systems. The approach is based on decomposing the complex multi-echelon problem into N + 1 single-echelon problems, using a near-optimal-induced backorder cost at the central warehouse. Important extensions made compared to earlier work include the addition of procedures to adjust for lead-time variability, and for undershooting the reorder point when customers’ order sizes vary. The result is a flexible model that is computationally and conceptually simple enough to be implemented in practice. A numerical study, including real data from the case company, illustrates that the new model outperforms existing methods in the literature. Compared to the current methods used by the case company, it offers significant improvements in both service-level fulfilment and system-wide inventory holding costs. Implementations of the model into the Syncron software are in progress.

Keywords
Inventory control, Stochastic models, Safety stocks, Heuristics, Vendor-managed inventory, Supply chain management
National Category
Transport Systems and Logistics Business Administration
Research subject
Technology (byts ev till Engineering), Industrial economy; Economy, Business administration; Economy, Logistics
Identifiers
urn:nbn:se:lnu:diva-32277 (URN)10.1080/00207543.2013.873555 (DOI)
Note

A corrigendum to this article was published in 2017:

(2017) Corrigendum, International Journal of Production Research, 55:17, 5183, DOI: 10.1080/00207543.2017.1322671

Available from: 2014-02-12 Created: 2014-02-12 Last updated: 2018-03-26Bibliographically approved
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