Bjørnar Aas

• Karalkova, Anastasiya; Aas, Bjørnar; Silva, Victor Anselmo & Cardoso, Eduardo Sampaio (2015). Gaining Flexibility and Responsiveness via Control and Integration of Logistics Information in Upstream Oil and Gas Logistics : Petrobras Case Study. I Jæger, Bjørn (Red.), NOFOMA 2015 : Post Conference Proceedings, Molde, 3-5 June 2015, Nordic Logistics Research Network. Nordic Logistics Research Network. ISSN 9788279622079. s. 128–143. Fulltekst i vitenarkiv Vis sammendrag

  The purpose of this paper is to advance research related to understanding of how flexibility and responsiveness is achieved in highly complex logistics environments during day-to-day operations. The main findings of the study reveal the importance of collaborative environment and integrated information, communication and decision-making structures in achievement of operational flexibility and responsiveness. Keywords: Flexibility, Responsiveness, Coordination, Oil and gas, Logistics, Offshore.

• Stojanović, Đurđica M. & Aas, Bjørnar (2015). Transport outsourcing and transport collaboration relationship : the risk hedging perspective. Serbian Journal of Management. ISSN 1452-4864. 10(1), s. 33–49. doi: 10.5937/sjm10-6676. Fulltekst i vitenarkiv Vis sammendrag

  Although transport outsourcing decision-making and collaborative transport management (CTM) have been “hot topics” for years, their links are still not thoroughly explored. The purpose of this paper is to contribute to a better understanding of the relationship between them. In particular, we focus on the conflicting and complementary features of these concepts with regard to their capability to hedge against transport outsourcing-related risks. Transport outsourcing is often a tool for transferring part of the demand risks from the primary parties in supply chains to transport service providers. However, new relationships introduce some new risks - outsourcing contract risks. It is important to identify, estimate and compare such kinds of risks. Transport collaboration may decrease both the demand risks and the outsourcing contract risks, although the relationship with the latter is more complex. It is used an exploratory research based on a combination of a literature review and empirical examples. Keywords: transport outsourcing, transport collaboration, demand risk and uncertainty, small and medium enterprises

• Vaagen, Hajnalka & Aas, Bjørnar (2014). A multidisciplinary framework for robust planning and decision-making in dynamically changing engineering construction projects. I Grabot, Bernard; Vallespir, Bruno; Gomes, Samuel; Bouras, Abdelaziz & Kiritsis, Dimitris (Red.), Advances in production management systems : innovative and knowledge-based production management in a global-local world : IFIP WG 5.7 International Conference, APMS 2014, Ajaccio, France, September 20-24, 2014, Proceedings, Part I. Springer. ISSN 9783662447383. s. 515–522. doi: 10.1007/978-3-662-44739-0_63. Fulltekst i vitenarkiv Vis sammendrag

  This paper proposes a multidisciplinary framework for robust planning and decision-making in dynamically changing engineering construction projects. The aim is to facilitate 'optimal' levels and 'trade-offs' between the major factors affecting decision-making throughout the project phases, to manage design changes and other disturbances, and to generate the maximum possible value. Offshore shipbuilding case analysis is applied to refine the model and to illustrate its value in decision-making. Keywords: construction project, uncertainty, lean, decision-making, behavior.

• Aas, Bjørnar & Wallace, Stein W. (2012). Management of logistics planning. I Wang, John (Red.), Information technologies, methods, and techniques of supply chain management. Idea Group Publishing. ISSN 9781466609181. s. 255–271. Fulltekst i vitenarkiv Vis sammendrag

  Logistics problems are gradually becoming more complex and a better understanding of logistics management as a subject is a key to deal with the new challenges. A core element of logistics management is logistics planning, which substitutes for low customer service levels, high waste, and the use of buffers and slacks in the execution of logistic activities. Furthermore, the availability of information and problem-solving capabilities are established as the core parts of logistics planning. Based on this, in this paper, a conceptual model for the management of logistics planning is proposed and discussed. In this regard, the model is built on ideas from microeconomics.

• Aas, Bjørnar & Wallace, Stein (2010). Management of logistics planning. International Journal of Information Systems and Supply Chain Management (IJISSCM). ISSN 1935-5726. 3(3), s. 1–17. Fulltekst i vitenarkiv Vis sammendrag

  Logistics problems are gradually becoming more complex and a better understanding of logistics management as a subject is a key to deal with the new challenges. A core element of logistics management is logistics planning, which substitutes for low customer service levels, high waste, and the use of buffers and slacks in the execution of logistic activities. Furthermore, the availability of information and problem-solving capabilities are established as the core parts of logistics planning. Based on this, in this paper, a conceptual model for the management of logistics planning is proposed and discussed. In this regard, the model is built on ideas from microeconomics.

• Aas, Bjørnar; Halskau, Øyvind & Wallace, Stein W. (2009). The role of supply vessels in offshore logistics. Maritime Economics & Logistics. ISSN 1479-2931. 11(3), s. 302–325. Fulltekst i vitenarkiv Vis sammendrag

  Oil companies are gradually becoming more focused on optimizing their upstream logistics. However, little research regarding upstream logistics has been published. We argue that more research would be beneficial and that more attention must be given to one of the largest cost elements in the upstream chain - the supply vessels. We explore the supply vessel as a means of transport and carry out a logistics analysis based on their use on the Norwegian continental shelf. Carrying capacity, sailing, loading and unloading capabilities are established as the main features of a supply vessel. Thereafter we discuss relevant logistical trade-offs within and among these features, and also in relation to the environment the vessels operate in. This elaboration clearly shows the complexity involved when searching for the "optimal" supply vessel. The analysis also indicates the design and logistics system features that should be challenged in the future. We believe that the findings in this article will be of considerable value for both practitioners and academics.

• Aas, Bjørnar; Buvik, Arnt & Cakic, Djurdjika (2008). Outsourcing of logistics activities in a complex supply chain : a case study from the Norwegian oil and gas industry. International Journal of procurement management. ISSN 1753-8432. 1(3), s. 280–296. doi: 10.1504/IJPM.2008.017526. Fulltekst i vitenarkiv Vis sammendrag

  This paper argues that the evolution of gradually more complex supply chains makes the logistics outsourcing decision more difficult and that a main reason for this is the increased number of interorganisational links that appear in complex supply chains. A wider Supply Chain Management (SCM) consideration seems to be warranted and the dyadic approach frequently taken in the outsourcing literature is not sufficient to provide adequate decision support in outsourcing decisions. The paper reviews the current literature on how interorganisational links should be regarded in an outsourcing decision process. A business case from the Norwegian oil and gas business is used to illustrate and analyse the broad problem scope and the complexity associated with the decision of possible outsourcing of the Supply Terminal Management (STM) within the framework of Transaction Cost Analysis (TCA) and SCM theory. The outcome of the empirical analysis shows that it is not beneficial to outsource the function when both economic and organisational factors are brought into consideration.

• Aas, Bjørnar; Gribkovskaia, Irina; Halskau, Øyvind & Shlopak, Alexander (2007). Routing of supply vessels to petroleum installations. International Journal of Physical Distribution & Logistics Management. ISSN 0960-0035. 37(2), s. 164–179. Fulltekst i vitenarkiv Vis sammendrag

  Purpose - In the Norwegian oil and gas industry the upstream logistics includes providing the offshore installations with needed supplies and return flow of used materials and equipment. This paper considers a real-life routing problem for supply vessels serving offshore installations at Haltenbanken off the northwest coast of Norway from its onshore supply base. The purpose of the paper is to explore how the offshore installation's limited storage capacity affects the routing of the supply vessels aiming towards creating efficient routes. Design/methodology/approach - A simplified version of the real-life routing problem for one supply vessel is formulated as a mixed integer linear programming model that contains constraints reflecting the storage requirements problem. These constraints ensure that there is enough capacity at the platform decks and that it is possible to perform both pickup and delivery services. Findings - The model has been tested on real-life-sized instances based on data provided by the Norwegian oil company Statoil ASA. The tests show that in order to obtain optimal solutions to the pickup and delivery problem with limited free storage capacities at installations, one has to include in the formulation the new sets of constraints, the storage feasibility and the service feasibility requirements. In addition, two visits to some platforms are necessary to obtain optimality. Research limitations/implications - The main limitation is the present inability to solve large cases. Originality/value - The contribution of this paper is to provide a better insight into a real-life routing problem which has a unique feature arising from the limited deck capacity at the offshore installations that complicates the performance of service. This feature has neither been discussed nor modeled in the vehicle routing literature before, hence the formulation of the problem is original and reveals some interesting results

• Aas, Bjørnar; Gribkovskaia, Irina; Halskau, Øyvind & Shlopak, Alexander (2006). Routing of supply vessels serving oil and gas installations in the Norwegian Sea, Economic order quantities assuming generalised order costs. NOFOMA. Fulltekst i vitenarkiv

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• Karalkova, Anastasiya; Aas, Bjørnar; Silva, Victor Anselmo & Cardoso, Eduardo Sampaio (2014). Coordination of upstream oil and gas logistics : integrated logistics operations center. Fulltekst i vitenarkiv
• Vaagen, Hajnalka & Aas, Bjørnar (2014). A multidisciplinary framework for robust planning and decision-making in dynamically changing engineering construction projects. Fulltekst i vitenarkiv
• Aas, Bjørnar (2009). Offshore logistics. Fulltekst i vitenarkiv
• Aas, Bjørnar (2009). New opportunities in logistics management. Fulltekst i vitenarkiv
• Aas, Bjørnar (2009). Finn balansen for logistikken. Fulltekst i vitenarkiv
• Aas, Bjørnar (2009). New opportunities in logistics management. Fulltekst i vitenarkiv
• Aas, Bjørnar (2008). Presentasjon av doktoravhandling: "Upstream logistics in offshore petroleum production". Fulltekst i vitenarkiv
• Aas, Bjørnar (2008). Hva ligger i styrende oppgaver? - Informasjon og påvirkning. Fulltekst i vitenarkiv
• Aas, Bjørnar; Wallace, Stein W. & Halskau, Øyvind (2008). The role of supply vessels in offshore logistics. Fulltekst i vitenarkiv
• Aas, Bjørnar (2008). Logistikkutfordringer og integrert logistikkplanlegging. Fulltekst i vitenarkiv
• Aas, Bjørnar & Wallace, Stein W. (2008). Management of logistics planning. Fulltekst i vitenarkiv Vis sammendrag

  We propose a conceptual framework for management of logistics planning. Logistics problems are gradually becoming more complex and the proposed framework contributes to a better understanding of logistics management as a subject. We believe that the application of the proposed framework could lead to more cost-efficient logistics planning. A case study from the oil-and gas industry is presented.

• Aas, Bjørnar; Buvik, Arnt & Cakic, Djurdjika (2007). Outsourcing of supply terminal management; a logistics activity in the supply chains for the oil and gas installations in the Norwegian Sea. Fulltekst i vitenarkiv Vis sammendrag

  For the last decades, the core competence concept has got great attention and the idea has been that it is preferable for companies to outsource activities not considered as "core business". Notwithstanding, several theoretical contributors have emphasized the many difficulties related to outsourcing decisions and several empirical studies have demonstrated that many companies keep their non-core logistics activities in-house. The authors of this article argue that the evolution of gradually more complex supply chains makes the logistics outsourcing decision more difficult and that a main reason for this is the increased number of inter-organizational links that appear in complex supply chains. A wider supply chain management consideration seems to be warranted and the dyadic approach frequently taken in the outsourcing literature is not sufficient to provide adequate decision support in outsourcing decisions. The authors review the current literature on how inter-organizational links should be regarded in an outsourcing decision process. A business case from the Norwegian oil and gas business is used to illustrate and analyse the broad problem scope and the complexity associated to the decision of possible outsourcing of the supply terminal management within the framework of transaction costs analysis and supply chain management theory. The outcome of the empirical analysis shows that it is not beneficial to outsource the supply terminal management when both economic and organizational factors are brought into consideration.

• Wallace, Stein W. & Aas, Bjørnar (2007). Supplying off-shore activities : from problem analysis to modeling. Fulltekst i vitenarkiv Vis sammendrag

  Off-shore oil and gas production is a major activity in Norway and other coastal nations. Supplying these activities with equipment and people is a major undertaking, both during drilling operations and production, particularly if the weather conditions are harsh. This presentation will focus on the activities in The Norwegian Sea, where production takes place at depths exceeding 1000 meters of water, and where weather can stop all supplies for weeks. The purpose of the talk is to outline the real case, discuss how modeling can take place, and what the major issues turned out to be. We end up focusing on how to describe wave forecasts as stochastic processes in cooperation with professional meteorologists, and how to use these forecasts for routing and loading vessels in light of uncertain weather conditions. A different issue turned out to be what parts of the supply chain should be outsourced in such an uncertain environment with extremely high failure (shortage) costs. There is also an issue of how to perform vehicle routing when both the vessels and the customers are capacity constrained. The goal in this presentation is not to present solutions, but rather to illustrate the modeling process.

• Aas, Bjørnar; Gribkovskaia, Irina; Shlopak, Alexander & Halskau, Øyvind (2006). Routing of supply vessels serving oil and gas installations in the Norwegian Sea. Fulltekst i vitenarkiv Vis sammendrag

  In the Norwegian oil and gas industry the upstream logistics includes providing the offshore installations with needed supplies and return flow of used materials and equipment. A part of these activities is planning of routes for supply vessels. This paper considers a real-life routing problem for supply vessels serving offshore installations at Haltenbanken outside the northwest coast of Norway from the supply base in Kristiansund. For the time being, the planning takes place for one vehicle at a time. Thus, we present the problem as a single vehicle routing problem with pickups and deliveries (SVRPPD). When solving this class of problems it was commonly assumed that all customers are visited once on a vehicle route shaped as a cycle. However, relaxation of the “one-visit” assumption can lead to different routing options that encompass the traditional cycle and may be superior in terms of travelling cost. In such non-traditional general solutions each customer is allowed to be visited either once for combined pickup and delivery, or twice, when the first visit is used for the delivery and pickup is performed on the second visit on the way back to the depot. Further, the reallife problem considered has a unique feature arising from the limited deck capacity at the offshore installations that complicates the performance of service and has never been treated in the literature on routing planning. This paper introduces a mixed integer linear programming model yielding general solutions for SVRPPD extended with a new set of constraints. The constraints ensure that there is enough free space at the platform deck and at the supply vessel deck to perform delivery and pickup operations. The model is tested on reallife sized instances based on data provided by the Norwegian oil company Statoil. Results of the tests show that in order to obtain optimal solutions to the SVRPPD with limited free storage capacities at installations one has to include in the formulation the possibility of two visits at platforms, the storage feasibility and the service feasibility requirements.

• Aas, Bjørnar (2006). Containers and load carriers used in the supply of offshore installations. Fulltekst i vitenarkiv
• Aas, Bjørnar (2006). Logistikkutfordringer. Fulltekst i vitenarkiv
• Aas, Bjørnar (2006). Neste generasjon forsyningsbåter. Fulltekst i vitenarkiv
• Halskau, Øyvind; Aas, Bjørnar & Gribkovskaia, Irina (2004). Pick-up and deliveries from a depot with capacity restrictions at the customers. Fulltekst i vitenarkiv
• Aas, Bjørnar & Wallace, Stein W. (2009). Management of logistics planning. Høgskolen i Molde. ISSN 9788279621171. Fulltekst i vitenarkiv Vis sammendrag

  We argue that logistics problems are gradually becoming more complex and that a better understanding of logistics management as a subject is a key to deal with the new challenges. A core element of logistics management is logistics planning. Logistics planning substitutes for low customer service levels, waste and the use of buffers and slacks in the execution of logistic activities. Furthermore, the availability of information and problem-solving capability are established as the core parts of logistics planning. Based on this, a conceptual model built on ideas from microeconomics is proposed and discussed. The outcome of the discussion shows that the knowledge that can be extracted from the proposed model is of high value for both practitioners and academics.

• Aas, Bjørnar; Dugnas, Karolis & Oterhals, Oddmund (2008). Modex - movable deck extender for offshore supply vessels : logistics impacts. Møreforsking Molde AS. Fulltekst i vitenarkiv Vis sammendrag

  The size of the deck area of an offshore supply vessel is an important issue. In some cases it is the most crucial design parameter for an operator's decision to order a vessel. Therefore, operators who need large deck capacity will find the MODEX TM solution interesting as this extends the deck area. The report focuses on the vessel operator (end customer) and will elaborate on the benefits of investing in such solution. It is particularly the logistics aspect that will be crucial to the product's usefulness. MODEX TM will provide increased load capacity and greater freedom to utilize the deck area. In addition, it is assumed that higher flexibility will also increase the vessel's ability to meet varying demand for transport, caused by periods of bad weather. Such benefits are weighed up against some negative logistiscs impacts and increased costs of hiring a supply vessel equipped with MODEX TM solution. How the solution affects the HSE aspects is discussed as well. The report concludes with a summary and recommendations, with the limitation that the analysis is mainly based on qualitative reasoning and qualitative understanding of the offshore supply problem.

• Aas, Bjørnar; Dugnas, Karolis & Oterhals, Oddmund (2008). MODEX - bevegelig, ekstra lastedekk for forsyningsfartøy : vurdering av logsitikkeffekter. Møreforsking. Fulltekst i vitenarkiv Vis sammendrag

  For operatører av forsyningsfartøy er størrelsen på dekksarealet en viktig parameter, og vil i noen tilfelle være den designparameteren som er avgjørende for hvilket fartøy man velger å kontrahere. Derfor, for operatører med behov for stor dekkskapasitet, vil et forsyningsfartøy utstyrt med MODEX (MOvable Deck EXtender) være interessant da dette gir en økning av dekksarealet. Rapporten fokuserer på sluttkunden (fartøy operatør) og vil underbygge nytteverdien av å investere i en slik løsning. Det er særlig logistikkfaglige aspekt som vil være avgjørende for produktets nytteverdi. MODEX vil gi økt lasteevne og større frihet til utnyttelse av dekksarealet. I tillegg antas det at fleksibiliteten også vil øke fartøyets evne til å møte varierende etterspørsel etter transport forårsaket av for eksempel perioder med dårlig vær. Slike fordeler veies opp i mot eventuelle andre negative logistikkonsekvenser og økte kostnader relatert til innleie av et forsyningsfartøy utstyrt med MODEX-løsning. Hvordan løsningen påvirker HMS aspekter drøftes også. Rapporten avsluttes med en oppsummering og anbefalinger, med forbehold om at analysen i hovedsak er basert på kvalitative resonnementer og en kvalitativ forståelse av forsyningsproblematikken.

• Aas, Bjørnar (2008). Upstream logistics in offshore petroleum production. Høgskolen i Molde - Vitenskapelig høgskole i logistikk. ISSN 9788279620983. Fulltekst i vitenarkiv
• Gribkovskaia, Irina; Halskau, Øyvind & Aas, Bjørnar (2005). Routing of supply vessels serving oil and gas installations in the Norwegian Sea. Høgskolen i Molde. ISSN 9788279620662. Fulltekst i vitenarkiv Vis sammendrag

  This paper considers a routing problem for a single vehicle with pick-up and delivery demands (SVRPPD) where all delivery demands start from a depot and all pickup demands are brought back to the depot serving a set of customers. Such problems are encountered in many practical situations. Traditionally such problems have been treated under an explicit assumption of backhauls - all delivery demands performed first and then all pickup demands at the end of the route - or tacitly - when such demands are mixed along the route, all customers are served one and only one time. However, recent research has shown that these traditional ways of solving such problems not always lead to the optimal result. If one relaxes the tacit assumption that all customers only shall be visited once, several different routing options can appear. One such solution can be a so-called lasso-solution. In such solution the first customer on a route is visited twice. On the first visit, only the delivery service is performed, hence creating more free space on the vehicle. On the way back to the depot, the same customer is visited a second time, now in order to perform the pickup service. Other types of sub-graphs can also be superior to the lasso solution and/or the traditional solutions. In this paper we relax the assumption that each installation only can be visited once and offer a mathematical model for solving SVRPPD. Further, tacitly in the SVRPPD it is always assumed that there are no capacity restrictions for storing goods at the customers' sites. We consider such a situation and offer an extended mathematical programming model for the SCRPPD with capacity restrictions at the customers. We apply these models to a real case. The case considered in this paper is taken from the Norwegian off-shore activities where a set of off-shore installations outside the west-coast of Norway are served by the use of supply vessels. In this real problem the oil and gas installations have limited space for storing cargo on the installations' deck. All the mathematical models presented and applied to the situation yield different optimal solutions to the real routing problem, showing the necessity of the extensions. Not very much research has been done on such kind of problems and a lot of new challenges and possibilities arise

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