liu.seSearch for publications in DiVA
Change search
Refine search result
1 - 35 of 35
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Gunnarsson, Helene
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Optimization approaches to tactical planning problems in the forest industry2004Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    By using decision support tools based on operations research (OR) and optimization in the supply chain in the forest industry, the planning process can be improved and higher profitability can be obtained. The focus of this thesis is on modelling two real-life problems. The problems are united by the facts that they concern tactical (annual) planning in the forest industry, and that the models are developed and tested with real data at Swedish companies.

    In the first paper, a problem of the supply chain of forest fuel is modelled and solved. The problem of deciding when and where forest residues are to be converted into forest fuel, and how the residues are to be t ransported and stored in order to satisfy demand at heating plants is studied. Decisions also include whether or not additional harvest areas and saw-mills are to be contracted. In addition, we consider the flow of products from saw-mills and import harbours, and address the question about which terminals to use. The planning horizon is one year and monthly time periods are considered. The test data is from Sydved Energileveranser AB.

    The second paper is a case study from Södra Cell AB. A combined problem of terminal location and ship routing is studied. The objective is to minimize the costs of distributing pulp products from pulp mills to customers (paper mills). Shipping vessels chartered on short or long term are used to transport products to terminals in Europe. In addition, trains and lorries are used for direct transports to customers from mills. From each terminal, the products are transported to customers by lorry, train, or a combination of both. Decisions about which terminals to use, which shipping routes to use, and which other transportation possibilities to use are included.

    In both problems, relatively large mixed integer programming (MIP) models have been developed and solved using a commercial lp (linear programming) solver. Heuristics have also been developed in both problems in order to obtain faster solutions. Several scenarios of the problems have been tested and evaluated.

    List of papers
    1. Supply chain modelling of forest fuel
    Open this publication in new window or tab >>Supply chain modelling of forest fuel
    2004 (English)In: European Journal of Operational Research, ISSN 0377-2217, Vol. 158, no 1, p. 103-123Article in journal (Refereed) Published
    Abstract [en]

    We study the problem of deciding when and where forest residues are to be converted into forest fuel, and how the residues are to be transported and stored in order to satisfy demand at heating plants. Decisions also include whether or not additional harvest areas and saw-mills are to be contracted. In addition, we consider the flow of products from saw-mills and import harbors, and address the question about which terminals to use. The planning horizon is one year and monthly time periods are considered. The supply chain problem is formulated as a large mixed integer linear programming model. In order to obtain solutions within reasonable time we have developed a heuristic solution approach. Computational results from a large Swedish supplying entrepreneur are reported.

    Keywords
    Supply chain management, Integer programming, Inventory, Transportation
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-14461 (URN)10.1016/S0377-2217(03)00354-0 (DOI)
    Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2013-11-07
    2. A combined terminal location and ship routing problem
    Open this publication in new window or tab >>A combined terminal location and ship routing problem
    2006 (English)In: Journal of the Operational Research Society, ISSN 0160-5682, Vol. 57, no 8, p. 928-938Article in journal (Refereed) Published
    Abstract [en]

    In this paper, we consider a combined terminal location and ship routing problem at Södra Cell AB. The purpose is to supply the customers' annual demand for pulp products while minimizing the distribution costs. Customers are supplied with various pulp products from pulp mills in Scandinavia by ships, trains, or lorries. The ship routes go from the pulp mills to terminals in Europe. From each terminal, the products are transported to customers by lorry, train, or barge. Some customers can be supplied directly from the pulp mills by trains or lorries. We have developed a mathematical model to select which terminals to use and, at the same time, determine the shipping routes. The mixed integer programming model was solved directly using a commercial solver. When the number of routes generated is large, the time required to obtain an optimal solution is too long. Hence, we have developed heuristics in order to obtain an acceptable solution in reasonable time. In addition to the basic case, five different scenarios were tested. Our heuristics provide solutions that are within 0.12% of the optimal ones.

    Keywords
    mixed integer programming, facility location, transportation, ship routing
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-14462 (URN)10.1057/palgrave.jors.2602057 (DOI)
    Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2013-11-07
  • 2.
    Gunnarsson, Helene
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Lundgren, Jan
    Linköping University, Department of Science and Technology.
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Decision support system/tools: Optimization of transportation, storage and chipping of forest fuel2003In: 2nd Forest Engineering Conference,2003, 2003, p. 74-82Conference paper (Other academic)
  • 3.
    Gunnarsson, Helene
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Lundgren, Jan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Supply chain modelling of forest fuel2003In: Systems analysis in forest resources :: proceedings of the eighth symposium, held September 27-30, 2000, Snowmass Village, Colorado, USA / [ed] Greg J. Arthaud and Tara M. Barrett, Kluwer , 2003, p. -326Chapter in book (Other academic)
    Abstract [en]

       Systems analysis in forestry has continued to advance in sophistication and diversity of application over the last few decades. The papers in this volume were presented at the eighth symposium in the foremost conference series worldwide in this subject area. Techniques presented include optimization and simulation modelling, decision support systems, alternative planning techniques, and spatial analysis. Over 30 papers and extended abstracts are grouped into the topical areas of (1) fire and fuels; (2) networks and transportation; (3) forest and landscape planning; (4) ecological modeling, biodiversity, and wildlife; and (5) forest resource applications. This collection will be of interest to forest planners and researchers who work in quantitative methods in forestry.

  • 4.
    Gunnarsson, Helene
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Department of Finance and Management Science, Norwegian School of Economics and Business Administration.
    Solving a multi-period supply chain problem for a pulp company using heuristics—An application to Södra Cell AB2008In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 116, no 1, p. 75-94Article in journal (Refereed)
    Abstract [en]

    In this paper, the integrated planning of production and distribution for a pulp company is considered. The tactical decisions included regard transportation of raw materials from harvest areas to pulp mills; production mix and contents at pulp mills; inventory; distribution of pulp products from mills to customers and the selection of potential orders and their levels at customers. The planning period is one year and several time periods are included. As a solution approach we make use of two different heuristic approaches. The main reason to use heuristics is the need for quick solution times. The first heuristic is based on a rolling planning horizon where iteratively a fixed number of time periods is taken into consideration. The second heuristic is based on Lagrangian decomposition and subgradient optimization. This provides optimistic bounds of the optimal objective function value that are better than the LP relaxation value, which can be used as a measure of the heuristic (pessimistic) solution quality. In addition, we apply the proposed rolling horizon heuristic in each iteration of the subgradient optimization. A number of cases based on real data is analysed which shows that the proposed solution approach is simple and provides high quality solutions.

  • 5.
    Gunnarsson, Helene
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Solving a multi-period supply chain problem for a pulp industry using Lagrangian heuristics based on time periods2007Report (Other academic)
  • 6.
    Gunnarsson, Helene
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Carlsson, Dick
    A combined terminal location and ship routing problem2004Report (Other academic)
  • 7.
    Gunnarsson, Helene
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Carlsson, Dick
    Integrated production and distribution planning of the supply chain for Södra Cell AB2004Report (Other academic)
  • 8.
    Gunnarsson Lidestam, Helene
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Supply chain optimization in the forest industry2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The scope of this thesis is modelling and solving large-scale planning problems in the supply chain within the forest industry. Five research papers are included, the first three of which focus on the modelling, and the last two on the solution methods. All problems included are tactical multi-commodity problems expressed as mixed integer programming (MIP) models. The work has been done in collaboration with two Swedish companies within the forest industry.

    In Paper I, a problem concerning the supply chain of forest fuel for Sydved Energileveranser AB is modelled and solved. We study the problem of deciding when and where forest residues are to be converted into wood chips, and how the residues and chips are to be transported and stored in order to satisfy energy demand at heating plants. The company has long-term contracts with forest owners and saw mills. Decisions in the model include whether or not additional harvest areas and saw mills are to be contracted and which terminals to use. The planning horizon is one year and monthly time periods are used.

    Papers II--V are based on planning problems at Södra Cell AB. The planning horizon is normally one year. Papers II--III consider only one time period. In Paper II the supply chain from pulp mills to customers is modelled and the combined problem of deciding terminal locations and which ship routes to use is studied. Shipping vessels chartered on short or long term are used to transport products to terminals in Europe. From each terminal, the products are transported to customers by truck, train, or a combination of both. In addition, trains and trucks can be used for transports directly to customers from mills. In Paper III the entire supply chain, from harvest areas to customers, is considered. Decisions included are transportation of raw materials, production mix, the distribution of pulp products, and the selection of potential orders and their quantities at customers. The ship routes are considered as flow links.

    In Papers IV--V the problems in Papers II--III are combined into one model and several time periods are used. Lagrangian heuristics based on Lagrangian decomposition are used as solution methods in both papers. In Paper IV, the approach leads to subproblems for each time period, whereas in Paper V, another approach that results in subproblems for different parts of the supply chain is developed.

    All models are based on real data from the companies. The models are detailed and describe the problems accurately. The solution methods are developed such that the solution time is kept within practical limits. Results from Papers II--III have been used by Södra Cell AB to support the change of the terminal structure as well as in budget planning.

    List of papers
    1. Supply chain modelling of forest fuel
    Open this publication in new window or tab >>Supply chain modelling of forest fuel
    2004 (English)In: European Journal of Operational Research, ISSN 0377-2217, Vol. 158, no 1, p. 103-123Article in journal (Refereed) Published
    Abstract [en]

    We study the problem of deciding when and where forest residues are to be converted into forest fuel, and how the residues are to be transported and stored in order to satisfy demand at heating plants. Decisions also include whether or not additional harvest areas and saw-mills are to be contracted. In addition, we consider the flow of products from saw-mills and import harbors, and address the question about which terminals to use. The planning horizon is one year and monthly time periods are considered. The supply chain problem is formulated as a large mixed integer linear programming model. In order to obtain solutions within reasonable time we have developed a heuristic solution approach. Computational results from a large Swedish supplying entrepreneur are reported.

    Keywords
    Supply chain management, Integer programming, Inventory, Transportation
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-14461 (URN)10.1016/S0377-2217(03)00354-0 (DOI)
    Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2013-11-07
    2. A combined terminal location and ship routing problem
    Open this publication in new window or tab >>A combined terminal location and ship routing problem
    2006 (English)In: Journal of the Operational Research Society, ISSN 0160-5682, Vol. 57, no 8, p. 928-938Article in journal (Refereed) Published
    Abstract [en]

    In this paper, we consider a combined terminal location and ship routing problem at Södra Cell AB. The purpose is to supply the customers' annual demand for pulp products while minimizing the distribution costs. Customers are supplied with various pulp products from pulp mills in Scandinavia by ships, trains, or lorries. The ship routes go from the pulp mills to terminals in Europe. From each terminal, the products are transported to customers by lorry, train, or barge. Some customers can be supplied directly from the pulp mills by trains or lorries. We have developed a mathematical model to select which terminals to use and, at the same time, determine the shipping routes. The mixed integer programming model was solved directly using a commercial solver. When the number of routes generated is large, the time required to obtain an optimal solution is too long. Hence, we have developed heuristics in order to obtain an acceptable solution in reasonable time. In addition to the basic case, five different scenarios were tested. Our heuristics provide solutions that are within 0.12% of the optimal ones.

    Keywords
    mixed integer programming, facility location, transportation, ship routing
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-14462 (URN)10.1057/palgrave.jors.2602057 (DOI)
    Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2013-11-07
    3. Integrated production and distribution planning for S¨odra Cell AB
    Open this publication in new window or tab >>Integrated production and distribution planning for S¨odra Cell AB
    2007 (English)In: Journal of Mathematical Modelling and Algorithms, ISSN 1570-1166, Vol. 6, no 1, p. 25-45Article in journal (Refereed) Published
    Abstract [en]

    In this paper we consider integrated planning of transportation of raw material, production and distribution of products of the supply chain at Södra Cell AB, a major European pulp mill company. The strategic planning period is one year. Decisions included in the planning are transportation of raw materials from harvest areas to pulp mills, production mix and contents at pulp mills, distribution of pulp products from mills to customer via terminals or directly and selection of potential orders and their levels at customers. Distribution is carried out by three different transportation modes; vessels, trains and trucks. We propose a mathematical model for the entire supply chain which includes a large number of continuous variables and a set of binary variables to reflect decisions about product mix and order selection at customers. Five different alternatives regarding production mix in a case study carried out at Södra Cell are analyzed and evaluated. Each alternative describes which products will be produced at which pulp mills.

    Keywords
    supply chain management; production planning; modelling; transportation; distribution, integer programming
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:liu:diva-14463 (URN)10.1007/s10852-006-9048-z (DOI)
    Available from: 2007-05-14 Created: 2007-05-14
    4. Solving a multi-period supply chain problem for a pulp company using heuristics—An application to Södra Cell AB
    Open this publication in new window or tab >>Solving a multi-period supply chain problem for a pulp company using heuristics—An application to Södra Cell AB
    2008 (English)In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 116, no 1, p. 75-94Article in journal (Refereed) Published
    Abstract [en]

    In this paper, the integrated planning of production and distribution for a pulp company is considered. The tactical decisions included regard transportation of raw materials from harvest areas to pulp mills; production mix and contents at pulp mills; inventory; distribution of pulp products from mills to customers and the selection of potential orders and their levels at customers. The planning period is one year and several time periods are included. As a solution approach we make use of two different heuristic approaches. The main reason to use heuristics is the need for quick solution times. The first heuristic is based on a rolling planning horizon where iteratively a fixed number of time periods is taken into consideration. The second heuristic is based on Lagrangian decomposition and subgradient optimization. This provides optimistic bounds of the optimal objective function value that are better than the LP relaxation value, which can be used as a measure of the heuristic (pessimistic) solution quality. In addition, we apply the proposed rolling horizon heuristic in each iteration of the subgradient optimization. A number of cases based on real data is analysed which shows that the proposed solution approach is simple and provides high quality solutions.

    Place, publisher, year, edition, pages
    Elsevier, 2008
    Keywords
    Supply chain modelling, Production planning, Heuristics, Lagrangian decomposition
    National Category
    Social Sciences
    Identifiers
    urn:nbn:se:liu:diva-14850 (URN)10.1016/j.ijpe.2008.07.010 (DOI)000261007900006 ()
    Note

    Original publication: Helene Gunnarsson and Mikael Rönnqvist, Solving a multi-period supply chain problem for a pulp company using heuristics—An application to Södra Cell AB, 2008, International Journal of Production Economics. http://dx.doi.org/10.1016/j.ijpe.2008.07.010. Copyright: Elsevier B.V., http://www.elsevier.com/

    Available from: 2008-09-26 Created: 2008-09-26 Last updated: 2017-12-13Bibliographically approved
    5. Solving a multi-period supply chain problem for a pulp industry using Lagrangian heuristics based on physical stages
    Open this publication in new window or tab >>Solving a multi-period supply chain problem for a pulp industry using Lagrangian heuristics based on physical stages
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14465 (URN)
    Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2010-01-13
  • 9.
    Gunnarsson (Lidestam), Helene
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lundgren, Jan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Supply chain modelling of forest fuel2004In: European Journal of Operational Research, ISSN 0377-2217, Vol. 158, no 1, p. 103-123Article in journal (Refereed)
    Abstract [en]

    We study the problem of deciding when and where forest residues are to be converted into forest fuel, and how the residues are to be transported and stored in order to satisfy demand at heating plants. Decisions also include whether or not additional harvest areas and saw-mills are to be contracted. In addition, we consider the flow of products from saw-mills and import harbors, and address the question about which terminals to use. The planning horizon is one year and monthly time periods are considered. The supply chain problem is formulated as a large mixed integer linear programming model. In order to obtain solutions within reasonable time we have developed a heuristic solution approach. Computational results from a large Swedish supplying entrepreneur are reported.

  • 10.
    Gunnarsson Lidestam, Helene
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Solving a multi-period supply chain problem for a pulp industry using Lagrangian heuristics based on time periodsManuscript (Other (popular science, discussion, etc.))
  • 11.
    Gunnarsson (Lidestam), Helene
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Carlsson, Dick
    Södra Cell AB, Växjö, Sweden.
    A combined terminal location and ship routing problem2006In: Journal of the Operational Research Society, ISSN 0160-5682, Vol. 57, no 8, p. 928-938Article in journal (Refereed)
    Abstract [en]

    In this paper, we consider a combined terminal location and ship routing problem at Södra Cell AB. The purpose is to supply the customers' annual demand for pulp products while minimizing the distribution costs. Customers are supplied with various pulp products from pulp mills in Scandinavia by ships, trains, or lorries. The ship routes go from the pulp mills to terminals in Europe. From each terminal, the products are transported to customers by lorry, train, or barge. Some customers can be supplied directly from the pulp mills by trains or lorries. We have developed a mathematical model to select which terminals to use and, at the same time, determine the shipping routes. The mixed integer programming model was solved directly using a commercial solver. When the number of routes generated is large, the time required to obtain an optimal solution is too long. Hence, we have developed heuristics in order to obtain an acceptable solution in reasonable time. In addition to the basic case, five different scenarios were tested. Our heuristics provide solutions that are within 0.12% of the optimal ones.

  • 12.
    Gunnarsson Lidestam, Helene
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Carlsson, Dick
    Södra Cell AB, Växjö, Sweden.
    Integrated production and distribution planning for S¨odra Cell AB2007In: Journal of Mathematical Modelling and Algorithms, ISSN 1570-1166, Vol. 6, no 1, p. 25-45Article in journal (Refereed)
    Abstract [en]

    In this paper we consider integrated planning of transportation of raw material, production and distribution of products of the supply chain at Södra Cell AB, a major European pulp mill company. The strategic planning period is one year. Decisions included in the planning are transportation of raw materials from harvest areas to pulp mills, production mix and contents at pulp mills, distribution of pulp products from mills to customer via terminals or directly and selection of potential orders and their levels at customers. Distribution is carried out by three different transportation modes; vessels, trains and trucks. We propose a mathematical model for the entire supply chain which includes a large number of continuous variables and a set of binary variables to reflect decisions about product mix and order selection at customers. Five different alternatives regarding production mix in a case study carried out at Södra Cell are analyzed and evaluated. Each alternative describes which products will be produced at which pulp mills.

  • 13.
    Johansson, Jens
    et al.
    Projektledare Miljöstyrningsrådet.
    Hoflin, Malin
    Projektassistent Miljöstyrningsrådet.
    Hollinder, Anders
    Energistrateg, Uppsala kommun.
    Hård af Segerstad, Louise
    Vice VD, Albaeco.
    Dalenstam, Eva
    Projektledare Miljöstyrningsrådet.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, Faculty of Science & Engineering.
    Norefjell, Fredric
    Jur. kand. & Ek. Mag, SP Sveriges tekniska forskningsinstitut, Borås.
    Pamlin, Dennis
    VD, 21st Century Frontiers.
    Thornéus, Joakim
    Projektledare för EPD,Miljöstyrningsrådet.
    Wadman, Sven
    Innovationsrådgivare,Mittuniversitetet, Östersund.
    Wall, Göran
    Docent Emeritus, Fysisk resursteori,Chalmers Tekniska Högskola.
    Miljöstyrningsrådets tankesmedja för transformativa lösningar i inköp och upphandling2014Report (Other academic)
    Abstract [sv]

    Transformativa upphandlingar är inget upphandlingsförfarande som finns beskrivet och reglerat i direktiv och lagar. Det transformativa inköpsarbetet är ett långsiktigt arbete som behöver påbörjas långt innan upphandlaren skriver ihop förfrågningsunderlaget, med andra ord handlar det om ett strategiskt inköpsarbete.

    Tankesmedjan är ett initiativ där individer från kommuner, landsting, statliga myndigheter, akademi och andra relevanta organisationer samlas för att undersöka hur dagens globala utmaningar kan vändas till möjligheter genom transformativa lösningar inom offentlig upphandling och inköp. Detta sker för att bidra till att uppnå de långsiktiga hållbarhetsmål som formulerats på internationell nivå, EU-nivå, nationell nivå och även i allt större utsträckning på lokal nivå.

    Tankesmedjans arbete med transformativa lösningar i inköp och upphandling utgår från den upphandlande organisationens behov i förhållande till hållbar utveckling.

    Tankesmedjans syfte är att se till alla aktiviteter som tillfredsställer organisationens behov av transformativa lösningar. Det kan vara lösningar som leder till innovationer men perspektivet är inte avgränsat till innovationer utan är ett helhetsperspektiv på alla möjliga lösningar.

    Tankesmedjan initierades och koordinerades av Miljöstyrningsrådet från början av 2013 och fram till Miljöstyrningsrådets nedläggning i juli 2014.

    Denna skrift är inte en vetenskaplig rapport och inte heller en utredning, det är snarare en stafettpinne. Den handlar om vad Tankesmedjan arbetat med under knappa omständigheter och hur vägen framåt för tankesmedjans fortsatta arbete ser ut nu när Tankesmedjan lämnas över till nästa aktör.

    Kanske kan skriften även tjäna som inspirationskälla till alla köpande organisationer att söka transformativa lösningar i inköp och upphandling.

  • 14.
    Lidestam, Helene
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Production Economics .
    Evaluating the public procurement for bus transports in terms of emissions and costs2008In: INFORMS Annual Meeting 2008,2008, 2008, p. 12-15Conference paper (Other academic)
  • 15.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics . Linköping University, The Institute of Technology.
    Evaluating the public procurement of bus transports in terms of emissions and costs2009Conference paper (Other academic)
    Abstract [en]

    The contracts resulting from a public procurement of bus transports in Sweden are very detailed. The specifications of, for example, used bus sizes can lead to unnecessary large buses in the sense that many of them are half empty. Other public procurement processes that could result in more flexible and less specified contracts and in turn reduced CO2-emissions will therefore be tested and evaluated by optimization models. Computational results from a large Swedish bus transport company are reported.

  • 16.
    Lidestam, Helene
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Logistics .
    Offentlig upphandling av busstransporter - En kartläggning av tidigare forskning2008Report (Other academic)
  • 17.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics . Linköping University, The Institute of Technology.
    Optimering av försörjningskedja: Artikeln beskriver optimering av försörjningskedjor vid Södra Cell AB och är en sammanfaning av en artikel Helene Lidestam (f. Gunnarsson) och Mikael Rönnqvist.tt -2009Report (Other (popular science, discussion, etc.))
  • 18.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Sustainable bus transports through less detailed contracts2014In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 61, p. 141-146Article in journal (Refereed)
    Abstract [en]

    The purpose of this paper is to investigate both environmental effects and cost effects of using less specified contracts regarding bus sizes in public bus transports. The process of choosing the best bid in the public procurement of bus transports is easier if the demands of the qualifications are well specified and detailed. On the other hand, detailed contracts can force the entrepreneurs to use less environmentally friendly and uneconomical alternatives. A mathematical model with binary variables is developed to evaluate the environmental and the economical effects of more optimized bus sizes. Computational results from a bus service provider are reported. The results of the model indicate that the emissions decrease considerably by using less detailed contracts. The results of a sub case indicate that the costs could be reduced as well, depending on how efficient the additional buses can be planned. The process of choosing the best bid in the public procurement process will be more complicated when the contracts are less detailed compared to current situations.

  • 19.
    Lidestam, Helene
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Abrahamsson, Mats
    Linköping University, Department of Management and Engineering, Logistics Management. Linköping University, The Institute of Technology.
    Environmental evaluation of public procurement for bus transports2010In: Management of environmental quality, ISSN 1477-7835, E-ISSN 1758-6119, Vol. 21, no 5, p. 645-658Article in journal (Refereed)
    Abstract [en]

    Purpose – The process of choosing the best part in the public procurement of bus transports is easier if the demands of the qualifications are well specified and detailed. On the other hand, detailed contracts will lead to limitations and could force the entrepreneurs to use uneconomical, but most of all, less environmentally friendly alternatives. The effects of using less specified contracts in order to achieve more environmentally friendly bus traffic have been tested and evaluated by optimization models. The paper aims to discuss these issues.

    Design/methodology/approach – A mathematical model with binary variables is developed to evaluate the environmental effects of more optimized bus sizes. Computational results from a bus service provider are reported. Different scenarios have been tested in order to evaluate the environmental effects of less detailed contracts.

    Findings – The results of the mathematical model indicate that all parts involved in the public procurement process, the public authority, the entrepreneur and the customers, will gain from more flexible and less detailed contracts.

    Research limitations/implications – The bus system in this study is limited to data from one region in Sweden. However, a pre-study indicates that this region is representative with regard to public procurement of bus transports in Sweden as well as in major parts of Europe.

    Originality/value – In terms of the total environmental impact from the public transport system, the paper focuses on the importance of creating relevant and less detailed contracts in public procurement. A mathematical model and data from a Swedish bus service provider have been used.

  • 20.
    Lidestam, Helene
    et al.
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Abrahamsson, Mats
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Optimerad offentlig uphandling av busstjänster: Miljökonsekvenser av dagens detaljerade upphandling av busstrafik2010Report (Other academic)
    Abstract [sv]

    Resultatet från beräkningarna indikerar att det finns en attraktiv potential i att ändra upphandlingsform till mer flexibla och mindre detaljerade kontrakt som är värd att undersöka vidare, inte minst i termer av mindre emissioner, men också i form av lägre kostnader. En potential som är gynnsam för alla parter som är inblandade i den offentliga upphandlingsprocessen av busstransporter, myndigheter, bussentreprenörer samt kunderna. Resultatet, som är logiskt har sin grund i ett effektivare resursutnyttjande av bussarna, d.v.s. en anpassning av busstorlek efter behov.Den allmänna fallstudien visade på sänkta nivåer av CO2-emissioner då kontrakten var mer flexibla och innehöll färre restriktioner när det gäller val av busstyp. Nivåerna av CO2-emissioner minskade med 34 % då man jämförde det mest flexibla scenariot (scenario 4) med nuvarande situation i aktuellt område i Västtrafik (scenario 1). Resultaten från den specifika fallstudien indikerar att även kostnaderna kan minskas beroende på hur effektivt tilläggsbussarna kan planeras. Resultaten indikerar att emissionerna kan minska med upp till 47 % genom att använda mindre bussar i trafiken och att kostnaderna i värsta fall kommer att stiga med 10%. Vi kan i vilket fall som helst konstatera att det finns möjligheter att även minska kostnaderna genom att förbättra planeringsmöjligheterna. Detta skulle t.ex. kunna göras genom att expandera det område som ska planeras i syfte att bättre kunna dra fördel av samordningseffekter och stordriftsfördelar. Andra transportentreprenörer, såsom exempelvis taxiverksamhet, skulle kunna användas i tillägg till de ordinarie bussarna för att kunna öka flexibiliteten och kunna utnyttja bussarna mer effektivt. Fyllnadsgraden på bussarna i allmänhet kan förmodligen höjas om omloppen kan planeras utifrån en önskan om en jämn nivå av passagerare. Antalet på- och avstigande gällande de studerade bussturerna i den specifika fallstudien varierar mycket längs med turerna. Möjligheten att använda parkeringsplatser utmed turerna i tillägg till att använda bussgarage skulle minska antalet kilometer med tomma bussar. Ovanstående möjligheter kan utgöra riktningar för fortsatt forskning inom området för att ytterligare visa på möjligheterna att reducera både CO2-emissionerna såväl som kostnaderna betydligt. I syfte att få en mer heltäckande bild av området skulle andra aspekter såsom passagerarnas inställning till bussresande och fullsatta bussar samt beteende vid resande kunna beaktas i fortsatt forskning.Resultaten från våra beräkningar visar att detaljerade krav i kontrakten som är resultatet av den offentliga upphandlingsprocessen leder till ökade CO2-emissioner och troligtvis generellt högre kostnader. Därför anser vi det vara högst motiverat för politikerna att utvärdera det svenska systemet. Denna forskning kommer därför att bidra till det övergripande målet att reducera CO2-emissionerna. Aktörerna inom bussbranschen borde även vara intresserade av att få insikt i hur färre restriktioner i kontrakten kommer att påverka dem.Resultaten visar också styrkan i projektets systemansats, där vi har vidgat systemgränserna och gjort våra beräkningar för systemet som helhet. Det har tillåtit oss att betrakta systemet som aktörsneutralt vilket innebär att vi inte begränsas i vår44forskning av t. ex. legala hinder, organisatoriska barriärer, planeringsmässiga problem och praktiska begränsningar. Istället har vi optimerat systemet som helhet i syfte att minimera CO2-emissionerna och därefter kompletterat med beräkningar gällande vilka företagsekonomiska konsekvenser en implementering av ett sådant system skulle medföra, först därefter har vi lyft fram de eventuella problem som i så fall måste lösas.Riktningar för fortsatt forskning skulle kunna vara att jämföra data från denna region med andra regioner i Sverige. Ett annat närliggande problem är att finna den optimala storleken på bussarna i tillägg till att beakta en bussflotta av en given storlek.

  • 21.
    Lidestam, Helene
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Ronnqvist, Mikael
    Norwegian School of Economic and Business Administration.
    Use of Lagrangian decomposition in supply chain planning2011In: Mathematical and computer modelling, ISSN 0895-7177, E-ISSN 1872-9479, Vol. 54, no 9-10, p. 2428-2442Article in journal (Refereed)
    Abstract [en]

    The integrated planning of transportation of raw material, production and distribution of products of the supply chain for a large pulp company is studied. The planning period is one year and a number of time periods are considered. The tactical decisions included in the model regard transportation of raw materials from harvest areas to pulp mills, production mix and contents at pulp mills, distribution of pulp products from mills to customers either via terminals or directly, and the selection of potential orders and their levels at customers. A mixed integer linear programming model for the supply chain problem is developed. The main solution method in this paper is a Lagrangian heuristic method based on Lagrangian decomposition. The heuristic divides the problem into two subproblems representing different physical stages in the supply chain, each including several time periods. The advantage of the proposed solution approach is that it generates feasible solutions of high quality in short time. A number of cases based on real data is analysed.

  • 22.
    Lidestam, Helene
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering.
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Solving a multi-period supply chain problem for a pulp company using Lagrangian heuristics based on physical stages2008In: Beyond Business Logistics, Helsinki, Finland: Anniversary NOFOMA , 2008, p. 233-248Conference paper (Other academic)
    Abstract [en]

      

  • 23.
    Lindholm, Anna
    et al.
    Lund University, Sweden.
    Giselsson, Pontus
    Lund University, Sweden.
    Quttineh, Nils-Hassan
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Johnsson, Charlotta
    Lund University, Sweden.
    Forsman, Krister
    Perstorp AB, Sweden.
    Production Scheduling in the Process Industry2013In: Proceedings for 22nd International Conference on Production Research, 2013, 2013Conference paper (Refereed)
    Abstract [en]

    The purpose of this paper is to formulate an optimization model for the production scheduling problem at continuous production sites. The production scheduling activity should produce a monthly schedule that accounts for orders and forecasts of all products. The plan should be updated every day, with feedback on the actual production the previous day. The actual daily production may be lower than the planned production due to disturbances, e.g. disruptions in the supply of a utility. The work is performed in collaboration with Perstorp, a world-leading company within several sectors of the specialty chemicals market. Together with Perstorp, a list of specifications for the production scheduling has been formulated. These are formulated mathematically in a mixed-integer linear program that is solved in receding horizon fashion. The formulation of the model aims to be general, such that it may be used for any process industrial site.

  • 24.
    Lindholm, Anna
    et al.
    Lund University, Sweden.
    Johnsson, Charlotta
    Lund University, Sweden.
    Quttineh, Nils-Hassan
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Henningsson, Mathias
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Wikner, Joakim
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Tang, Ou
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Nytzén, Nils-Petter
    Perstorp AB, Sweden.
    Forsman, Krister
    Perstorp AB, Sweden.
    Hierarchical Scheduling and Utility Disturbance Management in the Process Industry2013In: Proceedings for IFAC Conference on Manufacturing Modelling, Management and Control (MIM2013), 2013, Elsevier, 2013, p. 140-145Conference paper (Refereed)
    Abstract [en]

    The integration of scheduling and control in the process industry is a topic that has been frequently discussed during the recent years, but many challenges remain in order to achieve integrated solutions that can be implemented for large-scale industrial sites. In this paper we consider production control under disturbances in the supply of utilities at integrated sites together with the integration towards production scheduling. Utilities, such as steam and cooling water, are often shared between the production areas of a site, which enables formulation of an optimization problem for determining the optimal supply of utilities to each area at the occurrence of a disturbance. Optimization in two timescales is suggested to handle the scheduling and disturbance management problems in a hierarchical fashion. The suggested structure has been discussed with companies within the chemical process industry. A simple example is provided to show how the structure may be used

  • 25.
    Lindholm, Anna
    et al.
    Lund University, Sweden.
    Quttineh, Nils-Hassan
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Hierarchical Production Scheduling: A Case Study at Perstorp2014In: 24th European Symposium on Computer Aided Process Engineering / [ed] Jiří Jaromír Klemeš, Petar Sabev Varbanov and Peng Yen Liew, Elsevier, 2014, p. 511-516Conference paper (Refereed)
    Abstract [en]

    Planning and scheduling are functions that have large economic impact in the chemical process industry. For integrated sites with many interconnected production areas, obtaining production schedules that respect all production-related constraints is a complex task. One important issue is the constraints due to disturbances in utilities, such as steam and cooling water. These are often site-wide disturbances that may make it impossible to maintain desired production rates in several production areas at a site. In this study, scheduling at two levels of the functional hierarchy at a site of a world lead chemical industry, Perstorp, is handled. The activities are denoted production scheduling (PS) and detailed production scheduling (DPS). Real data of incoming orders and utility disturbances are used to produce a production schedule and detailed production schedule for one month. The PS and DPS problems are formulated as optimization problems, where production-related constraints such as production rate constraints, inventory limitations, and start-up costs are included. The objective functions of the PS and DPS problems are formulated to reflect the importance of different issues at the site. The procedure aims to show how the hierarchical optimization framework may be used to provide decision support for how to operate the production at a site in order to maximize profit while minimizing the effects of site-wide disturbances.

  • 26.
    Quttineh, Nils-Hassan
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Using rolling horizon techniques in the planning process for a chemical process industry2014In: Pre-Prints, Vol.1, 18th International Working Seminars on Production Economics, Innsbruck, Austria, February 2014., 2014, p. 381-393Conference paper (Refereed)
    Abstract [en]

    We present a mathematical optimization model that can be used as a decision support tool for the supply chain planning at Perstorp Oxo AB, a global company in the process industry. At their site in Stenungsund, Perstorp Oxo AB produce chemicals to customers in a variety of branches and for further refinement at other Perstorp sites in Gent, Castellanza and Perstorp. The customers are mainly in branches such as food and feed, leather and textile, plastic and safety glass production. Since Perstorp Oxo sells products to customers worldwide, two large inventory facilities are located in Antwerp (Belgium) and Tees (United Kingdom) for five product types each and two smaller facilities in Philadelphia (USA) and Aveiro (Portugal) for one type respectively. The developed model is a mixed-integer linear program, where the objective function maximizes the profit. A solution to the model shows the quantities to be transported between the different sites, production rates, inventory levels, setups and purchases from external suppliers, each with its respective cost. Based on actual sales data from Perstorp Oxo AB, we use rolling horizon techniques to simulate how customer demands vary over a time horizon of one year, and show that our optimization model is able to find feasible and profitable production plans. The results show that there is a potential to increase profit margin by using a decision support tool based on an optimization model.

  • 27.
    Quttineh, Nils-Hassan
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Ahlstedt, Mårten
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Olsson, Sven
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Supply Chain Planning at a Chemical Process Industry2013In: Proceedings for Decision Science Institute (DSI 2013), The 44th Annual Meeting, 2013, Decision Sciences Institute , 2013, p. 671895 - 1-671895 - 19Conference paper (Other academic)
    Abstract [en]

    The purpose of this paper is to develop a mathematical optimization model that can be used as a decision support tool for the supply chain planning at Perstorp Oxo AB, a global company in the process industry. At their site in Stenungsund, Perstorp Oxo AB produce chemicals to customers in a variety of branches and for further refinement at other Perstorp sites in Gent, Castellanza and Perstorp. The customers are mainly in branches such as food and feed, leather and textile, plastic and safety glass production. Since Perstorp Oxo sells products to customers worldwide, two large inventory facilities are located in Antwerp (Belgium)and Tees (United Kingdom) for five product types each and two smaller facilities in Philadelphia (USA) and Aveiro (Portugal) for one type respectively. The developed model is a mixed-integer linear program, where the objective function maximizes the profit margin, that is, the difference between the selling price and the cost of production, transportation, inventory carrying and outsourcing. A solution to the model shows the quantities to be transported between the different sites, production rates, inventory levels, setups and purchases from external suppliers, each with its respective cost. The results of a baseline scenario show that there is a potential to increase profit margin by using a decision support tool based on an optimization model.

  • 28.
    Rudberg, Martin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Waldemarsson, Martin
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Strategic Perspectives on Energy Management: A Case Study in the Process Industry2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 104, p. 487-496Article in journal (Refereed)
    Abstract [en]

    It has been anticipated that energy management will gain increased interest amongst companies in a near future. Yet, even in energy-intensive companies, like process industries, energy management is seldom treated strategically. The purpose of this study is thus to investigate the necessary prerequisites for putting energy management on the strategic agenda in energy-intensive process industries. This is done by the means of a literature review and a case study, and the analysis is based on how energy management is treated from three perspectives; a strategic perspective, an energy system utilisation perspective, and an alternative revenue perspective. The case study shows, similar to other process industry companies, that the strategic importance of energy management, to a large extent, is neglected. The research also indicates necessary prerequisites, for each perspective, for highlighting the strategic importance of energy management for a typical company in the process industry sector.

  • 29.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy issues in supply chain and production planning in the steel industry: A case study at SSAB2014Manuscript (preprint) (Other academic)
    Abstract [en]

    How can a different planning of production and supply chain increase energy efficiency and effectiveness? This descriptive and rather exploratory case study investigates these possibilities by mapping the production system and its supporting energy system at a steel company’s production site. Several possibilities for improvement in the planning processes have been located and evaluated. Our findings resulted in identifying four different improvement areas: 1) planning slab furnaces, 2) utilizing embedded heat and shortening lead times, 3) broader frame when scheduling for decreasing waste at set-ups, and 4) demandresponse opportunities related to electricity price variations. The first improvement area: planning of the slab furnaces, shows the largest potential, both in terms of energy savings and reduced costs. The second and the third improvement areas are similar to each other in terms of potential energy savings, but if the lead-time also could be decreased in the second it would be more economically beneficial than the other. Additional possibilities are found in the fourth improvement area where electricity demand response actions by rescheduling the energy-intensive production into times of low electricity price might save electricity costs. To conclude, the company could reach both higher energy efficiency and profitability simultaneously, by utilizing the energy- and the production systems combined in a more efficient and effective way.

  • 30.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy issues in supply chain and production planning in the steel industry: A case study at SSAB2014In: in Grubbström, R.W, Hinterhuber, H.H., (Eds), PrePrints, Vol. 1, 18th International Working Seminar on Production Economics, Innsbruck, Austria, 2014, p. 489-501Conference paper (Other academic)
    Abstract [en]

    This paper investigates the possibilities of merging suitable processes for energy management into operations management processes within a steel company. The descriptive and rather exploratory case study maps the production system and its supporting energy system within one of the company’s production sites. Several possibilities for improvement in the planning processes have been located and evaluated. Our findings resulted in that four different improvement areas could be identified: planning furnace ovens, utilizing embedded heat and shortening lead times, wider scheduling for decreasing waste at set-ups, and demand-response opportunities related to electricity price variations. Improved planning of the furnace ovens shows the largest potential, both in terms of energy savings and reduced costs. To utilize embedded heat and to reduce waste at set-ups are similar to each other in terms of potential energy savings, but if the lead-time also could be decreased the economical benefits would excel. There are moreover possible economical benefits of electricity demand response actions by rescheduling the energy-intensive production into times of low electricity price. To conclude, the company could reach both higher environmental performance and economical profitability simultaneously, and thus utilizing the energy- and the production systems combined in a more efficient and effective way.

  • 31.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    How energy affects supply chain planning at a pulp company2013In: 22nd International Conference on Production Research (ICPR 22), 2013Conference paper (Refereed)
    Abstract [en]

    Integrated planning of the supply chain at a multi-site pulp company has previously been considered, in whichenergy are included with respect to its revenue generating capabilities. When energy intense raw materials notonly give fiber to the pulp process but also generate an energy surplus, there is room for different planningapproaches to maximize the total profit. This paper deeply analyses the model with more analytical scenariosand reveals promising changes that can be done in terms of both refining the current planning, but also byimproving the production system and its corresponding energy system. The scenarios considered involvemarket changes for energy demand and price, and alternative production opportunities. The scenarios arecross-analyzed and compared in order to reveal additional relations that are worthy to consider. The findingstherefore point out the usefulness of the model and its advantages.

  • 32.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, Faculty of Science & Engineering.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    How energy price changes can affect production- and supply chain planning – A case study at a pulp company2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 203, p. 15p. 333-347Article in journal (Refereed)
    Abstract [en]

    The process industry in general is very energy-intensive, and therefore models focusing on energy can be very important in order to reach higher profitability. In this study, an optimization model of the supply chain in a pulp company, where energy is included with respect to its revenue generating capabilities, is used. Using real company data, and through an analysis of the model’s results, we show that higher profitability can be achieved when integrating energy into the planning process. Our findings show that when energy-intensive raw materials not only provide fibre to the pulp process but also generate an energy surplus, there is room for different planning approaches in order to maximize the total profit. This paper reveals promising changes that can be made for improving the current planning process. The scenarios considered involve market changes for energy demand and price, and also alternative production opportunities. A cross-analysis compares the scenarios in order to reveal additional relations that are important to consider. Depending on a price change of energy, the model prioritizes in its selection of pulp products to produce. From this we provide guidelines on where and when to increase or decrease pulp production. The model shows that the company can increase its total profit no matter which of the included energy parameters that increase in price. The paper contributes to previous research by enhancing the usefulness of this model for not only the case company as such, but also by illustrating and describing how the approach applied can be useful for other cases within the energy intensive industry.

  • 33.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Rudberg, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Including energy in supply chain planning at a pulp company2012In: Proceedings of the Fourth International Conference on Applied Energy (ICAE) 2012, 2012Conference paper (Refereed)
    Abstract [en]

    In this paper we consider integrated planning of the supply chain at a multi-site pulp company. In addition to the traditional focus on pulp products, also energy aspects are considered, both in the form of raw material and as revenue generating products. The idea is that energy intense raw materials not only gives fiber to the pulp process but also generates an energy surplus that can be used in different ways to create additional value or revenues. The planning horizon is one year and monthly time periods are considered. Decisions included in the planning are purchase and transportation of raw materials from harvest areas to pulp mills, production allocation by dividing the production among the pulp mills, energy mix by choosing the energy input at the pulp mills and distribution of products from mills to customer. An MILP model for the entire supply chain is proposed. A number of different scenarios including real data from the case company are analyzed and evaluated. The aim of the study is thus to investigate the effects on profitability while taking energy issues in consideration.

  • 34.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Rudberg, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Including energy in supply chain planning at a pulp company2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 1056-1065Article in journal (Refereed)
    Abstract [en]

    In this paper we consider integrated planning of the supply chain at a multi-site pulp company. In addition to the traditional focus on pulp products, also energy aspects are considered, both in the form of raw material and as revenue generating products. The idea is that energy intense raw materials not only gives fibre to the pulp process but also generates an energy surplus that can be used in different ways to create additional value or revenues. The planning horizon is one year and monthly time periods are considered. Decisions included in the planning are; purchase and transportation of raw materials from harvest areas to pulp mills, production allocation by dividing the production among the pulp mills, energy mix by choosing the energy input at the pulp mills, and distribution of products from mills to customer. An MILP model for the entire supply chain is proposed. A number of different scenarios including real data from the case company are analyzed and evaluated. The aim of the study is thus to investigate the effects on profitability while taking energy issues into consideration.

  • 35.
    Waldemarsson, Martin
    et al.
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Rudberg, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Lidestam, Helene
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, The Institute of Technology.
    Energy management in process industries:current practices and future challenges2010In: Proceedings of the 17th EurOMA Conference, 2010, 2010Conference paper (Other academic)
    Abstract [en]

    Previous research indicates a great potential within process industries regarding the use, distribution, and supply of energy, affecting manufacturing costs and revenues. The purpose of this study is thus to analyze, and to provide suggestions for improvements for, energy management in a process industry company. This will be done by mapping the energy flow and usage for a case company. The results of this study indicate that a strategic perspective on energy issues is necessary in order to reach the full potential of energy savings and for establishing an effective energy management system.

1 - 35 of 35
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf