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High productivity in forest harvesting requires efficient forwarding. Planning is complicated by multiple choices of routes and their order, the number and types of assortments, the loading sequence, and pile organization at the landing. This paper develops and tests a decision support tool for forwarder routing with sequential co-loading of assortments. Input data are the harvester production file (including Global Navigation Satellite Systems tracking), placement of landing, and machine specifications. The trail network is generated from the harvester production data when devising routes to pick up all log piles, including specific assortments and volumes. Multiple assortments can be loaded along each route, and a certain loading sequence of assortments is preferred and (or) required. Sorting time during co-loading varies, depending on the assortment combinations and bunk loading pattern. Route planning is modeled using a set-partitioning problem, and the solution method is a metaheuristic based on repeated matching. In addition to routes and loading sequences, solutions include the organization of assortment piles at the landing, depending on the total volume of each assortment. The tool produces similar results to those attained by skilled forwarder operators on five clearcuts (3-11 ha) in northern Sweden, when the results are compared with data from actual forwarder production files. Key words: forest operations, forwarding, routing, skid trails, sequencing Une productivite elevee dans l'exploitation forestiere necessite des porteurs efficaces. La planification est rendue complexe par les multiples choix des itineraires et de leur ordre, le nombre et les types d'assortiments, la sequence de chargement et l'organisation des piles au debarcadere. Cet article developpe et teste un outil d'aide a la decision pour le routage des porteurs avec le co-chargement sequentiel des assortiments. Les donnees d'entree sont le fichier de production de l'abatteuse (y compris le suivi GNSS), le placement de l'atterrissage et les specifications de la machine. Le reseau de pistes est genere a partir des donnees de production de l'abatteuse lors de la conception des itineraires de ramassage de toutes les piles de grumes, y compris les assortiments et les volumes specifiques. Plusieurs assortiments peuvent etre charges le long de chaque route, et une certaine sequence de chargement des assortiments est preferee ou requise. Le temps de triage pendant le co- chargement varie en fonction des combinaisons d'assortiments et du schema de chargement des troncs. La planification des itineraires est modelisee a l'aide d'un probleme de partitionnement d'ensembles, et la methode de solution est une metaheuristique basee sur la correspondance repetee. En plus des itineraires et des sequences de chargement, les solutions incluent l'organisation des piles d'assortiments au debarcadere, en fonction du volume total de chaque assortiment. L'outil produit des resultats similaires a ceux obtenus par des operateurs de porteurs qualifies sur cinq coupes a blanc (3-11 ha) dans le nord de la Suede, lorsque les resultats sont compares aux donnees des fichiers de production reels des porteurs. [Traduit par la Redaction] Mots-cles : operations forestieres, acheminement, routage, pistes de derapage, sequencage, Introduction Efficient forwarding is essential for high productivity in cut-to-length harvesting operations. Planning the wood extraction on a clearcut is a demanding task, with multiple and complex decisions about route [...]

In recent years, increasing attention has been drawn to improving productivity in logging passages while reducing negative impact on soil and water. The position of landings and extraction routes is crucial in these efforts, as it has a huge impact on efficient and sustainable forwarder passages. In this paper, we propose a two-phase approach to identify the best possible landing locations integrated with log extraction route design. The first phase identifies potential landing zones adjacent to forest roads. It considers practical restrictions such as slopes, stoniness, and closeness to infrastructure. The second phase uses an optimization model to evaluate the potential impact of each zone and aggregate zones, selecting one or two complete landings. This model is a relaxation of a formulation for an extraction route design; it is used to minimize a weighted objective of the total driving distance, avoid steep terrains and impact on soil and water. The proposed approach has been tested on a set of harvest areas in southern Sweden. The results not only show the potential to identify feasible landing zones but also identify a shorter driving distance and hence lower contractual cost with optimized positioning. The possibility to increase efficiency in forest operations by performing scenario analysis and thus forwarding distances with different landing sites is among the results. Key words: forest operations, decision support system, optimization, forest landings, forwarding operations. Au cours des dernieres annees, une attention croissante a ete accordee a l'amelioration de la productivite des operations forestieres tout en reduisant les impacts negatifs sur l'eau et le sol. La localisation des jetees et des routes de sortie est cruciale dans le cadre de ces efforts etant donne que cela a un impact enorme sur l'efficacite et la durabilite des chemins utilises par les porteurs. Dans cet article, nous proposons une approche qui comporte deux phases pour identifier la meilleure localisation possible des jetees integree a la conception des chemins de sortie des billes. La premiere phase sert a identifier les zones potentielles de jetees adjacentes aux chemins forestiers. Elle tient compte des restrictions pratiques, telles que les pentes, la pierrosite et la proximite des infrastructures. La seconde phase utilise un modele d'optimisation pour evaluer l'impact potentiel de chaque zone et regrouper les zones en choisissant une ou deux jetees completes. Ce modele est une relaxation d'une formulation pour la conception des chemins de sortie; il est utilise pour minimiser un objectif pondere de la distance totale de deplacement, eviter les terrains abrupts et les impacts sur l'eau et le sol. L'approche proposee a ete testee sur un ensemble d'aires de coupe dans le sud de la Suede. Les resultats demontrent non seulement la capacite d'identifier les zones de jetees realisables mais identifie aussi une distance de conduite plus courte et par consequent un cout contractuel plus bas avec un positionnement optimise. La possibilite d'augmenter l'efficacite des operations forestieres en effectuant une analyse de scenarios et par consequent de distances de debardage avec differents sites de jetees fait partie des resultats. [Traduit par la Redaction] Mots-cles: operations forestieres, systeme d'aide a la decision, optimisation, jetees forestieres, debardage., Introduction The location of landing(s) in forest operations is the decoupling point between harvest and transport operations. A landing should be close to the harvest area to enable efficient forwarding [...]

In forest transportation in Quebec, transportation rates are typically based on an estimated trip or travel time duration during which a truck travels loaded from an origin to a destination and then returns empty to the origin. These transportation rates implicitly consider fuel consumption for fuel surcharge costs in negotiation, but for most shippers and carriers, fuel consumption remains a rough estimate, leading to underestimation or overestimation of actual consumption. In this paper, we propose a new fuel consumption model and a more detailed trip time computation to support accurate estimations. The model takes into account road network characteristics that affect fuel consumption, such as road elevation profiles, including slopes that significantly affect fuel consumption compared to flat roads, and curves where trucks change speed, as well as intersections where trucks need to stop or slow down. The road network of the province of Quebec (Canada) is represented in a route network that integrates all the characteristics considered by the fuel consumption model. The model is validated in a case study using a timber truck equipped with GPS and information about overall fuel consumption between a set of refueling points. Utilizing the fuel consumption model and a route planner enables accurate estimation of fuel consumption and, consequently, associated greenhouse gas (GHG) emissions and travel times. A case study involving three companies is then conducted to analyze how more detailed information can inform new transportation rates. [ABSTRACT FROM AUTHOR]

Improving productivity in forest logging operations while reducing negative impact on soil and streams has gained increasing attention. Positioning primary extraction routes is crucial in these efforts, as it has a huge impact on efficient and sustainable forwarder passages. To minimize the total forwarding distance and avoid steep terrain and impact on soil and water, we developed a decision support system, including a detailed optimization model and solution method. The main source of information consisted of a detailed digital terrain model, depth-to-water maps, and forest volume density. The information was supplemented with the extent of the stand, position of the landing(s), nature and culture conservation sites, and any known unavoidable crossings in the terrain (e.g., streams). Because fast solution time was a critical requirement, we developed a decomposition method based on Lagrangian relaxation. The system was evaluated in two case studies in Sweden. In the first case, the optimization model performance was analyzed at 30 final harvesting sites. In the second case, experienced forest company staff evaluated the primary extraction routes at 19 harvest sites in operational conditions. The results indicated that the model allowed for faster planning, shorter driving distances, and the potential to reduce negative impact on soil and water. Key words: forest operations, decision support system, optimization, routing, network design, forwarding operations. L'amelioration de la productivite de l'exploitation forestiere tout en reduisant l'impact negatif sur le sol et les cours d'eau attire de plus en plus d'attention. L'emplacement des routes primaires d'extraction est crucial dans le cadre de ces efforts etant donne que cela a un impact enorme sur l'efficacite et la durabilite des deplacements des porteurs. Un systeme d'aide a la decision qui inclut un modele detaillee d'optimisation et une methode de solution a ete developpe afin de minimiser la distance totale de debardage et d'eviter les reliefs escarpes ainsi que reduire l'impact negatif sur le sol et l'eau. La principale information comprenait un modele numerique detaille de terrain, des cartes indiquant la profondeur de la nappe phreatique et la densite du volume ligneux. L'information a ete completee avec l'etendue du peuplement, la position des jetees, les sites dedies a la conservation de la nature et presentant un interet culturel ainsi que tout croisement inevitable connu sur le terrain (p. ex. les cours d'eau). Un temps de resolution rapide du modele etait une exigence cruciale, d'ou l'elaboration d'une methode de decomposition fondee sur la relaxation lagrangienne. Le systeme a ete evalue dans deux etudes de cas en Suede. Dans le premier cas, la performance du modele d'optimisation a ete analysee dans 30 sites de coupe finale. Dans le second cas, le personnel experimente de la compagnie forestiere a evalue les routes primaires d'extraction dans 19 sites de coupe dans des conditions operationnelles. Les resultats indiquent que la planification est plus rapide, que les distances de deplacement sont plus courtes et qu'il serait possible de reduire l'impact negatif sur le sol et l'eau. [Traduit par la Redaction] Mots-cles: exploitation forestiere, systeme d'aide a la decision, optimisation, trace, conception de reseaux, operations de debardage., Introduction In recent years, improving productivity in forest logging operations while reducing negative impact on soil and streams has gained increasing attention. In the latter case, ground conditions at regeneration [...]

Transportation is a key forest logistics component and is a large proportion of the overall cost. Often, the transportation cost is determined by contractual agreements and based on the loaded distance from a supply to a demand point. Many alternative routes provide different distances (e.g., shortest route, fastest route, minimum fuel consumption), but these distances are approximate in the contractual agreement; hence, there is a mismatch between approximated costs and actual pay. It is necessary to match supply with demand when planning to use optimization models, as these models must cover many supply and demand points. From this point, many distances need to be established. These can be generated dynamically before optimization or generated a priori as static distance tables. The former can take a long time, whereas the latter needs to use aggregated zones that remain static over time because supply points, such as harvest areas, change continually. To enable fast optimization, distances between zones and demand points can be precomputed; however, they represent only estimated distances between the actual supply point and the demand points. We propose a hybrid method to improve quality and estimate accurate distances in a quick process, using a large case study from a company in Sweden with a standardized system that directly uses computed reference distances as contractually agreed. Results show that many distance estimation approaches give poor cost estimates (1–20%) and increase transportation costs (0.2–0.6%). [ABSTRACT FROM AUTHOR]

Abstract Background Epidural anaesthesia and analgesia are indicated for oesophageal surgery. A rare but serious complication is spinal haematoma, which can occur on insertion, manipulation or withdrawal of catheters. Evidence and guidelines are vague regarding which tests are appropriate and how to interpret their results. We aimed to describe how routine coagulation test results change during oesophagectomy’s perioperative course. Methods Following ethical approval, we retrospectively identified patients who had undergone oesophagectomy between 2002 and 2012. Blood test results and details of operations, haemorrhage and complications were recorded and analysed with Excel and R. A literature search was conducted using the PubMed terms ‘epidural’ AND ‘coagulation’ AND English language. Relevant articles published in 2000 and after were included. Results Three hundred and seven patients received a thoracic epidural infusion with bupivacaine and morphine while 51 received an intravenous morphine infusion. Tests taken preoperatively and before the planned withdrawal of the epidural catheter demonstrated increases in all three measures: aPTT (activated partial thromboplastin time), PT-INR (prothrombin international normalised ratio) and platelet count (Plc). Postoperative thrombocytopenia was almost non-existent while aPTT or PT-INR was elevated above the reference range in 129/307 patients: aPTT was elevated in 116/307 while PT-INR was elevated in 32/307. This is too small a sample to allow meaningful estimation of risk of spinal haematoma: it may be as high as 2.3%. The literature search returned 275 articles, of which 57 were relevant. Twenty-one concerned the natural history of postoperative coagulation; 16, the incidence of and risk factors for spinal haematoma; and 5, evaluation of specific blood tests. Postoperative coagulation is characterised by thrombocytosis and transient moderately abnormal routine coagulation test results. Viscoelastic tests are not validated in the stable postoperative setting. Conclusions Screening for coagulopathy before removal of epidural catheters is of unclear benefit since elevated aPTT and PT-INR are usual and may not indicate hypocoagulation. A thorough clinical assessment is important. We nevertheless recommend caution when being presented with elevated routine tests of coagulation before withdrawing an epidural catheter: viscoelastic haemostatic tests may have a role in testing before withdrawal of epidural catheters but they are so far not validated. Future research should include advanced coagulation analysis as soon as a patient is unfortunate enough to have a spinal haematoma.

Each year, more than three million animals are transported from farms to abattoirs in Sweden. Animal transport is related to economic and environmental costs and a negative impact on animal welfare. Time and the number of pick-up stops between farms and abattoirs are two key parameters for animal welfare. Both are highly dependent on efficient and qualitative transportation planning, which may be difficult if done manually. We have examined the benefits of using route optimization in cattle transportation planning. To simulate the effects of various planning time windows and transportation time regulations and number of pick-up stops along each route, we have used data that represent one year of cattle transport. Our optimization model is a development of a model used in forestry transport that solves a general pick-up and delivery vehicle routing problem. The objective is to minimize transportation costs. We have shown that the length of the planning time window has a significant impact on the animal transport time, the total driving time and the total distance driven; these parameters that will not only affect animal welfare but also affect the economy and environment in the pre-slaughter logistic chain. In addition, we have shown that changes in animal transportation regulations, such as minimizing the number of allowed pick-up stops on each route or minimizing animal transportation time, will have positive effects on animal welfare measured in transportation hours and number of pick-up stops. However, this leads to an increase in working time and driven distances, leading to higher transportation costs for the transport and negative environmental impact.

When a company is integrated vertically, it can manage and plan its overall value chain in one direct and integrated approach. However in many cases, companies follow a decoupled approach where forests and production plants optimize separately their processes in a supply-driven strategy. In Chile, the two largest forest companies are vertically integrated (i.e., they own forest and mills that produce logs, lumber, plywood, pulp, paper, and bioenergy, etc.). Historically, they have coordinated their value chains using a make-to-stock strategy, for which the forest is the main driver of the value chain activities. In this paper, we propose an integrated planning approach to show the impacts of a demand-driven integration of the value chain in the forest industry. To compare this strategy with the decoupled strategy, we propose a mixed integer programming (MIP) model for the integrated strategy. To illustrate our proposal, we use forest and production information from a Chilean forest company. The decoupled strategy, where the forest and industry planning are planned separately, uses two models. The first model deals with the forest management and harvesting decisions and maximizes the expected net present value (NPV) of logs. In this model, the planning horizon covers one full forest rotation, which in Chile corresponds to about 25 years. The second model maximizes the NPV of the downstream operations for a shorter business planning horizon (five years) constrained by the availability of the logs from the first model. In the integrated approach, all parts of the value chain (forest, transportation, and mills) are driven by final product demand and where the objective is to maximize the profit of the company (NPV of the entire value chain). The demand is only given for the shorter business planning horizon. The two strategies are evaluated using the MIP model, and NPV is used to determine the best practice. According to the results, the NPV can increase up to 5.0% when the proposed integrated strategy is implemented compared to a decoupled strategy. Moreover, the profit for the business period increases up to 8.5%. Key words: value chain management, forest industry, push and pull strategies, long term forest planning, mixed integer programming. Lorsqu'une compagnie est integree verticalement, elle a la possibilite d'utiliser une approche directe et integree pour gerer et planifier de facon globale sa chaine de valeur. Cependant, dans plusieurs cas, les compagnies adoptent une approche decouplee oU les forets et les usines de production optimisent leurs processus separement selon une strategie dictee par l'approvisionnement. Au Chili, les deux plus importantes compagnies forestieres sont integrees verticalement, c.-a-d. qu'elles possedent des forets et des usines qui produisent des grumes, du bois d'oeuvre, du contreplaque, de la pate, du papier, de la bioenergie, etc. Historiquement, elles ont coordonne leurs chaines de valeur en adoptant une strategie de production sur stock selon laquelle la foret est le principal moteur des activites de la chaine de valeur. Dans cet article, nous proposons une approche de planification integree pour illustrer les impacts d'une integration de la chaine de valeur controlee par la demande dans l'industrie forestiere. Pour comparer cette strategie avec la strategie decouplee, nous proposons un modele de programmation partiellement en nombres entiers pour la strategie integree. Pour illustrer notre proposition, nous utilisons les informations au sujet de la foret et de la production d'une compagnie forestiere chilienne. Les strategies decouplees oU la planification forestiere et la planification industrielle sont effectuees separement utilisent deux modeles. Le premier modele porte sur les decisions d'amenagement et d'exploitation de la foret et maximise la valeur actualisee nette (VAN) attendue des grumes. Dans ce modele, l'horizon de planification s'etend sur une revolution complete de la foret qui correspond a environ 25 ans au Chili. Le second modele maximise la VAN des activites en aval sur un horizon de planification des affaires plus court (cinq ans) en ayant comme contrainte la disponibilite des grumes selon le premier modele. Dans l'approche integree, tous les maillons de la chaine de valeur (foret, transport et usines) dependent de la demande du produit final et l'objectif consiste a maximiser les profits de la compagnie (VAN de l'ensemble de la chaine de valeur). La demande est fixee seulement pour l'horizon plus court de planification des affaires. Les deux strategies sont evaluees a l'aide du modele de programmation partiellement en nombres entiers et la VAN est utilisee pour determiner les meilleures pratiques. Selon les resultats, l'augmentation de la VAN peut atteindre 5 % lorsque la strategie integree qui est proposee est appliquee comparativement a la strategie decouplee. De plus, l'augmentation des profits pour la periode planification des affaires peut atteindre 8,5 %. [Traduit par la Redaction] Mots-cles : gestion de la chaine de valeur, industrie forestiere, strategies pousser-tirer, planification forestiere a long terme, programmation partiellement en nombres entiers., Introduction The value chain (VC) in the forest industry starts with harvesting operations, where different log types (e.g., saw logs, pulp logs, and fuel logs) are produced in the bucking [...]

To keep businesses competitive in world markets, the number of farms in most countries is decreasing while farm size is increasing, and parcels making up the farm area are extremely fragmented. It is common for farms to expand faster than available arable land near the farm center, leading to longer distances between the farm center and field areas. Consequently, logistic costs increase and affect the farm's profitability and the environment. Moreover, there is often substantial overlap between different farms, which implies that it is possible for farmers to collaborate with each other. We developed and proposed three optimization models to describe different levels of collaboration and sharing restrictions. Many practical considerations need to be weighed, such as the soil type and crops used. We collected detailed information on farms, parcels, and cost drivers in seven large instances for our case study in Sweden. One instance had 1431 farms and 32,091 parcels with 96 crop types. The resulting optimization models were very large; special pre‐processing and optimization techniques were developed for their solutions. The theoretical potential for collaboration in logistic cost reduction was very large, ranging from approximately 10% to 50% depending on the form of the collaboration. Because a large part of costs comes from less use of diesel for transport resources, the reduction in cost is directly related to a reduction in CO2 emissions. [ABSTRACT FROM AUTHOR]