• 2D-packing with an application to stowage in Roll-on Roll-off liner shipping 

      Hansen, Jone; Hukkelberg, Ivar; Fagerholt, Kjetil; Stålhane, Magnus; Rakke, Jørgen Glomvik (Journal article; Peer reviewed, 2016-08-14)
      Roll-on/Roll-off (RoRo) ships represent the primary source for transporting vehicles and other types of rolling material over long distances. In this paper we focus on operational decisions related to stowage of cargoes ...
    • A genetic search-based heuristic for a fleet size and periodic routing problem with application to offshore supply planning 

      Borthen, Thomas; Loennechen, Henrik; Wang, Xin; Fagerholt, Kjetil; Vidal, Thibaut (Journal article; Peer reviewed, 2017-08-22)
      This paper introduces a genetic search-based heuristic to solve an offshore supply vessel planning problem (SVPP) faced by the Norwegian oil and gas company Statoil. The aim is to help the company in determining the optimal ...
    • A New Formulation for the Combined Maritime Fleet Deployment and Inventory Management Problem 

      Dong, Bo; Bektas, Tolga; Chandra, Saurabh; Christiansen, Marielle; Fagerholt, Kjetil (Journal article; Peer reviewed, 2017-09-27)
      This paper addresses the fleet deployment problem and in particular the treatment of inventory in the maritime case. A new model based on time-continuous formulation for the combined maritime fleet deployment and inventory ...
    • A Shortest Path Heuristic for Evaluating the Quality of Stowage Plans in Roll-On Roll-Off Liner Shipping 

      Hansen, Jone R.; Fagerholt, Kjetil; Stålhane, Magnus (Journal article; Peer reviewed, 2017-09-27)
      Roll-on Roll-off shipping companies transport rolling cargo, such as cars, trucks and large construction machines. When sailing, this type of cargo must be attached to the deck using chains, to prevent damaging the cargo. ...
    • A survey on maritime fleet size and mix problems 

      Pantuso, Giovanni; Fagerholt, Kjetil; Hvattum, Lars Magnus (Journal article; Peer reviewed, 2014-06-01)
      This paper presents a literature survey on the fleet size and mix problem in maritime transportation. Fluctuations in the shipping market and frequent mismatches between fleet capacities and demands highlight the relevance ...
    • A variable neighbourhood search heuristic for disruption management in offshore oil and gas logistics 

      Stålhane, Magnus; Albjerk, Nils; Danielsen, Teodor; Krey, Stian; Fagerholt, Kjetil (Journal article; Peer reviewed, 2018-04-18)
      This paper studies operational planning and disruption management in offshore oil and gas logistics. A significant amount of time is currently spent on operational planning, and major costs are caused by disruptions to the ...
    • A vessel pickup and delivery problem from the disruption management in offshore supply vessel operations 

      Albjerk, Nils; Danielsen, Teodor; Krey, Stian; Stålhane, Magnus; Fagerholt, Kjetil (Journal article; Peer reviewed, 2016-06-10)
      This paper considers a vessel pickup and delivery problem that arises in the case of disruptions in the supply vessel logistics in the offshore oil and gas industry. The problem can be modelled as a multi-vehicle pickup ...
    • Benchmark Suite for Industrial and Tramp Ship Routing and Scheduling Problems 

      Hemmati, Ahmad; Hvattum, Lars Magnus; Fagerholt, Kjetil; Norstad, Inge (Journal article; Peer reviewed, 2014-07-01)
      This paper considers a class of cargo ship routing and scheduling problems from industrial and tramp shipping and presents a wide range of benchmark instances that have been created to represent realistic planning problems ...
    • Heuristics for dynamic and stochastic routing in industrial shipping 

      Tirado, Gregorio; Hvattum, Lars Magnus; Fagerholt, Kjetil; Cordeau, Jean-François (Journal article; Peer reviewed, 2013-01)
      Maritime transportation plays a central role in international trade, being responsible for the majority of long-distance shipments in terms of volume. One of the key aspects in the planning of maritime transportation systems ...
    • Maritime fleet deployment with speed optimization and voyage separation requirements 

      Borander, Venke; Straume, Anders; Dong, Bo; Fagerholt, Kjetil; Wang, Xin (Journal article; Peer reviewed, 2018-09-20)
      A shipping company operates a heterogeneous fleet of ships to service a given number of voyages on a number of trade routes over the planning horizon. Each ship has a predefined speed range within which it can sail. Fuel ...
    • Maritime routing and speed optimization with emission control areas 

      Fagerholt, Kjetil; Gausel, Nora Therese; Rakke, Jørgen Glomvik; Psaraftis, Harilaos (Journal article; Peer reviewed, 2015-03)
      Strict limits on the maximum sulphur content in fuel used by ships have recently been imposed in some Emission Control Areas (ECAs). In order to comply with these regulations many ship operators will switch to more expensive ...
    • Maximizing the rate of return on the capital employed in shipping capacity renewal 

      Mørch, Ove; Fagerholt, Kjetil; Pantuso, Giovanni; Rakke, Jørgen Glomvik (Journal article; Peer reviewed, 2017)
      Decisions regarding investments in capacity expansion/renewal require taking into account both the operating fitness and the financial performance of the investment. While several operating requirements have been considered ...
    • Offshore supply planning in a rolling time horizon 

      Fernandez Cuesta, Eirik; Andersson, Henrik; Fagerholt, Kjetil (Journal article; Peer reviewed, 2018-09-20)
      This paper presents a real transportation problem stemming from offshore oil and gas logistics and shows how optimization models used in a rolling horizon simulation framework can be very valuable to assess and improve the ...
    • On two speed optimization problems for ships that sail in and out of emission control areas 

      Fagerholt, Kjetil; Psaraftis, Harilaos (Journal article; Peer reviewed, 2015)
      This paper deals with two speed optimization problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulfur emissions. For ships crossing in and out of ECAs, such as deep-sea vessels, ...
    • Operational planning for routes and schedules for a fleet of fuel supply vessels 

      Christiansen, Marielle; Fagerholt, Kjetil; Rachaniotis, Nikos; Stålhane, Magnus (Journal article; Peer reviewed, 2017-09)
      This paper considers a real operational problem of routing and scheduling a fleet of fuel supply vessels used to service customer ships anchored outside a major port. The problem can be formulated as a rich multi-trip ...
    • Optimization in offshore supply vessel planning 

      Halvorsen-Weare, Elin Espeland; Fagerholt, Kjetil (Journal article; Peer reviewed, 2016)
      This paper considers the offshore supply vessel (OSV) planning problem, which consists of determining an optimal fleet size and mix of OSVs as well as their weekly routes and schedules for servicing offshore oil and gas ...
    • Planning for charters: A stochastic maritime fleet composition and deployment problem 

      Wang, Xin; Fagerholt, Kjetil; Wallace, Stein W. (Journal article; Peer reviewed, 2017-08-04)
      This paper introduces a chartering problem that arises in the shipping industry. The chartering decisions determine the time-charter contracts to enter into, in particular, how many ships of each type to charter in, and ...
    • Robust planning and disruption management in roll-on roll-off liner shipping 

      Sola Fischer, Andreas; Nokhart, Håkon Stavn; Olsen, Henrik; Fagerholt, Kjetil; Rakke, Jørgen Glomvik; Stålhane, Magnus (Journal article; Peer reviewed, 2016)
      This paper presents different strategies for handling disruptions in fleet deployment in roll-on roll-off liner shipping, which basically consists of assigning a fleet of vessels to predefined voyages at minimum cost. A ...
    • Vessel routing and scheduling under uncertainty in the liquefied natural gas business 

      Halvorsen-Weare, Elin Espeland; Fagerholt, Kjetil; Rönnqvist, Mikael (Journal article; Peer reviewed, 2013)
      Liquefied natural gas (LNG) is natural gas transformed into liquid state for the purpose of transportation mainly by specially built LNG vessels. This paper considers a real-life LNG ship routing and scheduling problem ...