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Articles containing the keyword 'procurement'.

Category: Research article

article id 5659, category Research article
Juha Laitila, Anssi Ahtikoski, Jaakko Repola, Johanna Routa. (2017). Pre-feasibility study of supply systems based on artificial drying of delimbed stem forest chips. Silva Fennica vol. 51 no. 4 article id 5659. https://doi.org/10.14214/sf.5659
Highlights: With artificial drying and quick delivery, avoiding dry material losses of harvested timber, it could be possible to reduce the current costs of the prevailing procurement system based on natural drying of stored timber at roadside landings; The maximum cost for the prospective drying process of fresh chips corresponds to, e.g., organization costs or stumpage price of delimbed stems.

This study was aimed at determining the maximum cost level of artificial drying required for cost-efficient operation. This was done using a system analysis approach, in which the harvesting potential and procurement cost of alternative fuel chip production systems were compared at the stand and regional level. The accumulation and procurement cost of chipped delimbed stems from young forests were estimated within a 100 km transport distance from a hypothetical end use facility located in northern Finland. Logging and transportation costs, stumpage prices, tied up capital, dry matter losses and moisture content of harvested timber were considered in the study. Moisture content of artificially dried fuel chips made of fresh timber (55%) was set to 20%, 30% and 40% in the comparisons. Moisture content of fuel chips based on natural drying during storing was 40%. Transporting costs were calculated according to new higher permissible dimensions and weight limits for truck-trailers. The procurement cost calculations indicated that with artificial drying and by avoiding dry material losses of timber, it could be possible to reduce current costs of the prevailing procurement system based on natural drying of timber at roadside landings. The maximum cost level of artificial drying ranged between 1.2–3.2 € MWh–1 depending on the supply chain, moisture content and procurement volume of fuel chips. This cost margin corresponds to, e.g., organization, forwarding and transportation costs or stumpage price of delimbed stems.

  • Laitila, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@luke.fi (email)
  • Ahtikoski, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Paavo Havaksen tie 3, FI-90570 Oulu, Finland ORCID ID:E-mail: anssi.ahtikoski@luke.fi
  • Repola, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Eteläranta 55, FI-96300 Rovaniemi, Finland ORCID ID:E-mail: jaakko.repola@luke.fi
  • Routa, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: johanna.routa@luke.fi
article id 1280, category Research article
Juha Laitila, Tapio Ranta, Antti Asikainen, Eero Jäppinen, Olli-Jussi Korpinen. (2015). The cost competitiveness of conifer stumps in the procurement of forest chips for fuel in Southern and Northern Finland. Silva Fennica vol. 49 no. 2 article id 1280. https://doi.org/10.14214/sf.1280
Highlights: Pre-grinding and integrated screening is a way of guaranteeing fuel quality, but, when the stumps’ ash content is six per cent or below, the procurement costs are higher than with grinding of stumps at the plant. Because of high transportation costs, stump harvesting is the most profitable in Southern Finland, where there is greater availability of stumps than in Northern Finland.
The aim of this study was to evaluate cost competitiveness, at regional level, of various systems for stump transportation and grinding, and to compare the results to the procurement costs of delimbed stems from early thinnings at the stand and regional level. The accumulation and procurement costs of stumps and delimbed stems were estimated within a 100-kilometer radius from two power plants located in Kouvola and in Kajaani. The analyses were performed as simulated treatments in clear cuts and thinnings of young stands, using existing productivity and cost functions, alternative ash percentages for stump wood, and yield calculations based on the forest industry regeneration felling stand data and the sample plots data of the National Forest Inventory of Finland. The results were expressed as Euros per solid cubic meter (€ m–3) and Euros per megawatt hour (€ MWh–1). The results highlight the need to improve stump fuel quality and increase the heating value. The procurement cost of stumps was about 1 € MWh–1 lower in Kouvola compared to Kajaani, when using conceivable ash content of 6% for stumps ground at the plant, and ash content of 1.5% for stumps pre-ground at the roadside landing. The procurement costs of stumps were, on average, 0.55 € MWh–1 lower compared to delimbed stems in Kouvola, and on average 0.6 € MWh–1 higher in Kajaani. Pre-grinding and integrated screening is a feasible way to guarantee the fuel quality expressed as ash content already at roadside landings, but the procurement costs are higher compared to grinding stumps at the plant, when the ash content of ground stumps is 6% or less.
  • Laitila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@metla.fi (email)
  • Ranta, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@lut.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.asikainen@metla.fi
  • Jäppinen, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: eero.jappinen@lut.fi
  • Korpinen, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: olli-jussi.korpinen@lut.fi
article id 51, category Research article
Sanna Hautamäki, Antti Mutanen, Jari Viitanen. (2012). Substitution in the Finnish forest industry’s roundwood procurement. Silva Fennica vol. 46 no. 3 article id 51. https://doi.org/10.14214/sf.51
In this study, the interaction and substitution between domestic and imported roundwood in the Finnish forest industry’s wood procurement is analysed by timber assortments. The results from the translog cost function approach and quarterly data of the total wood procurement and its components during the euro regime indicate that, to a certain extent, the Finnish forest industry has had the possibility of substituting imported roundwood volumes between countries in the Baltic Sea region. Contrary to earlier studies, also in the case of Russian birch pulpwood, the most important imported timber assortment, the results suggest that Russian birch pulpwood has rather substituted for than complemented the domestic supply in Finland. The increase in roundwood export duties in Russia has had a statistically significant effect on the trade in birch pulpwood and spruce sawlogs. Moreover, the results confirm the earlier findings of a rigid demand for roundwood in Finnish roundwood markets.
  • Hautamäki, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail:
  • Mutanen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.mutanen@metla.fi (email)
  • Viitanen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail:
article id 514, category Research article
Jukka Malinen. (2003). Locally adaptable non-parametric methods for estimating stand characteristics for wood procurement planning. Silva Fennica vol. 37 no. 1 article id 514. https://doi.org/10.14214/sf.514
The purpose of this study was to examine the use of the local adaptation of the non-parametric Most Similar Neighbour (MSN) method in estimating stand characteristics for wood procurement planning purposes. Local adaptation was performed in two different ways: 1) by selecting local data from a database with the MSN method and using that data as a database in the basic k-nearest neighbour (k-nn) MSN method, 2) by selecting a combination of neighbours from the neighbourhood where the average of the predictor variables was closest to the target stand predictor variables (Locally Adaptable Neighbourhood (LAN) MSN method). The study data used comprised 209 spruce dominated stands located in central Finland and was collected with harvesters. The accuracy of the methods was analysed by estimating the tree stock characteristics and the log length/diameter distribution produced by a bucking simulation. The local k-nn MSN method was not notably better than the k-nn MSN method, although it produced less biased estimates on the edges of the input space. The LAN MSN method was found to be a more accurate method than the k-nn methods.
  • Malinen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland ORCID ID:E-mail: jukka.malinen@joensuu.fi (email)
article id 698, category Research article
Kalle Kärhä, Sami Oinas. (1998). Satisfaction and company loyalty as expressed by non-industrial private forest owners towards timber procurement organizations in Finland. Silva Fennica vol. 32 no. 1 article id 698. https://doi.org/10.14214/sf.698
The satisfaction and company loyalty as expressed by non-industrial, private forest (NIPF) owners towards timber procurement organizations were clarified via a mail questionnaire. The results denoted that there is a positive correlation between the levels of forest owners’ expectations (EXP) and perceived performance (PERF). In addition, the lower EXP and the higher PERF were, the greater was the overall satisfaction index (SAT). About two thirds of forest owners were characterized by a negative SAT value or then they were dissatisfied with the performance of the procurement organization in their last timber-sales transaction. Furthermore, the results obtained indicated that the SAT index significantly influences the company loyalty expressed by NIPF owners – their willingness to give favourable reports of the company to the others, and their willingness to engage in future timber-sales transactions with the same company. Nonetheless, the SAT index did not affect the market share of a particular company, and this could be partly accounted for by the similar level of performance among the companies and the lack of competition in the timber trade. Finally, the results revealed several dimensions of timber procurement, and some seller segments to which companies could pay more attention to in order to be able to achieve better satisfaction levels and the loyalty of NIPF owners in the future. One approach to successfully addressing these challenges could be the adopting of a satisfaction decision support system (SatDSS).
  • Kärhä, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland ORCID ID:E-mail: karha@forest.joensuu.fi (email)
  • Oinas, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland ORCID ID:E-mail:

Category: Article

article id 7142, category Article
Seppo Ervasti. (1964). Suomen sahateollisuuden kausivaihtelu. 2. Tutkimustulokset. Acta Forestalia Fennica vol. 76 no. 2 article id 7142. https://doi.org/10.14214/aff.7142
English title: Seasonal variation in the sawmill industry of Finland II. Investigation results.

Seasonal variation in the sawmill industry of Finland was studied in an investigation based on questionnaires answered by a random sample of sawmills concerning the time period of 1958-1960. The method is described in detail in a separate article in Acta Forestalia Fennica issue 75 no. 1.

The seasonal variations in purchase of roundwood was largest in big sawmills, which purchase the main part of the timber as standing sales and buy most of the wood from the State Forest auctions at the end of September. Also, they can afford to reserve their material earlier than the smaller companies. The saw logs are mainly felled in the winter in Finland because the climatic conditions and availability of labour are best at that time. Small sawmills begin fellings a little earlier than the larger ones.

In long-transport of timber the proportion of floating decreased from 47% in 1958 to 38% in 1960. At the same time, proportion of truck transport increased from 48% to 55%. Small sawmills use almost exclusively land transport. They received almost three-fourths of their logs between January and May, because the sawing is concentrated in the first half of the year. Therefore, floating does not suit for their transport method. The larger the sawmill, the later is the seasonal peak of log deliveries. The output of the big sawmills is distributed more evenly thoughout the year. The smaller the sawmill, the quicker is the turnover of raw material and the smaller the sawlog inventories.

The seasonal variation in output is sharper at small sawmills where sawing is concentrated in the first half of the year. The seasonal peak of the early spring is due to the aim at getting the sawn wood to dry early enough for shipments in the summer. Air drying takes an average of 4 ½ months. Kiln drying is more common at the larger sawmills, and gives them more flexibility. Due to the large seasonal variation in operation, the capacity of the small mills is poorly utilized. Domestic sales of sawn wood levels up the seasonality of the deliveries. Export sales are concentrated at the end and turn of the year. Also, the seasonal peak of expenditure occurs in the winter, but that of income in the summer.

The PDF includes a summary in English.

  • Ervasti, ORCID ID:E-mail:
article id 5619, category Article
Pertti Harstela. (1997). Decision support systems in wood procurement. A review. Silva Fennica vol. 31 no. 2 article id 5619. https://doi.org/10.14214/sf.a8520

Many kinds of planning systems have been labelled decision support systems (DSS), but few meet the most important features of real DSSs in planning and control of wood procurement. It has been concluded that many reasons exist to develop DSSs for wood procurement. The purchasing of timber seems to be one of the most promising areas for DSS, because there is no formal structure for these operations and decisions deal with human behaviour. Relations between DSSs and different features of the new approaches in wood procurement are also discussed, and hypotheses for future studies suggested.

  • Harstela, ORCID ID:E-mail:
article id 5617, category Article
Teijo Palander. (1997). A local DLP-GIS-LP system for geographically decentralized wood procurement planning and decision making. Silva Fennica vol. 31 no. 2 article id 5617. https://doi.org/10.14214/sf.a8518

Linear programming (LP) is an important method for allocation of wood inventory stock. It is, for instance, used alone in tactical planning systems, which currently are in wide use at the higher hierarchical level in the functionally decentralized planning of the Finnish forest industry. Unfortunately, LP as a solution method has not been capable of handling spatial data that seem to characterize planning systems in geographical decentralization. In the present study, GIS was used to assimilate data from different wood procurement functions, to calculate transportation distances and cost figures, and to write the data in ASCII files, which were then used as input for the LP model. Using the experiments and methods of GIS on a planning system developed according to participatory planning, the results of this study suggest that the participatory method was faster than the conventional LP method, when solved using actual data. The participatory method was also capable of providing the same global optimum for a wood allocation problem. The implications of these results for improving operational and tactical planning of wood procurement in Finland are discussed.

  • Palander, ORCID ID:E-mail:
article id 5617, category Article
Teijo Palander. (1997). A local DLP-GIS-LP system for geographically decentralized wood procurement planning and decision making. Silva Fennica vol. 31 no. 2 article id 5617. https://doi.org/10.14214/sf.a8518

Linear programming (LP) is an important method for allocation of wood inventory stock. It is, for instance, used alone in tactical planning systems, which currently are in wide use at the higher hierarchical level in the functionally decentralized planning of the Finnish forest industry. Unfortunately, LP as a solution method has not been capable of handling spatial data that seem to characterize planning systems in geographical decentralization. In the present study, GIS was used to assimilate data from different wood procurement functions, to calculate transportation distances and cost figures, and to write the data in ASCII files, which were then used as input for the LP model. Using the experiments and methods of GIS on a planning system developed according to participatory planning, the results of this study suggest that the participatory method was faster than the conventional LP method, when solved using actual data. The participatory method was also capable of providing the same global optimum for a wood allocation problem. The implications of these results for improving operational and tactical planning of wood procurement in Finland are discussed.

  • Palander, ORCID ID:E-mail:
article id 5547, category Article
Tiina Tolvanen-Sikanen, Pertti Harstela, Lauri Sikanen. (1995). A game theoretic simulation model for quality oriented timber supply to sawmills. Silva Fennica vol. 29 no. 1 article id 5547. https://doi.org/10.14214/sf.a9198

The first aim of this study was to develop a simulation model describing the flow of different timber qualities to different firms. The second aim was to study preliminary the factors which affect timber distributions. In addition, we tested the hypothesis that in a small sawmill firm the traditional way of organizing timber procurement does not direct effectively good quality logs to the special production. The game theoretic approaching and the principles of Monte-Carlo simulation were applied in development of the simulation model. The most important factors of the model were tried to find for further studies with sensitive analysis. Empirical validation brought forth promising results in the area of one municipality. The buyer’s awareness of a marked stand, the seller’s willingness to sell a marked stand, the buyer’s ability to pay for wood and the proportion of first quality pine logs in a marked stand affected the distribution of pine logs. The results also supported the hypothesis that the traditional system, in which sawmills or their own forest departments procure themselves all timber needed, is not the most effective way to direct enough good quality timber to the special production.

  • Tolvanen-Sikanen, ORCID ID:E-mail:
  • Harstela, ORCID ID:E-mail:
  • Sikanen, ORCID ID:E-mail:
article id 7510, category Article
Arto Rummukainen, Heikki Alanne, Esko Mikkonen. (1995). Wood procurement in the pressure of change. Acta Forestalia Fennica no. 248 article id 7510. https://doi.org/10.14214/aff.7510

Linear optimization model was used to calculate seven wood procurement scenarios for years 1990, 2000 and 2010. Productivity and cost functions for seven cutting, five terrain transport, three long distance transport and various work supervision and scaling methods were calculated from available work study reports. All methods are based on Nordic cut to length conditions. Finland was divided in three parts for description on harvesting conditions. Twenty imaginary wood processing points and their wood procurement areas were created for these areas. The procurement systems, which consists of the harvesting conditions and work productivity function, were described as a simulation model. In the LP-model the wood procurement system has to fulfil the volume and wood assortment requirements of processing points by minimizing the procurement cost. The model consists of 862 variables and 560 restrictions.

Results show that it is economical to increase the mechanical work in harvesting. Cost increment alternatives effect only little on profitability of manual work. The areas of later thinnings and seed tree- and shelterwood cuttings increase on cost of first thinnings. In mechanized work one method, 10-tonne one grip harvester and forwarder, is gaining advantage among other methods. Working hours of forwarder are decreasing opposite to the harverster. There is only little need to increase the number of harvesters and trucks or their drivers from today’s level. Quite large fluctuations in level of procurement and cost can be handled by constant number of machines, by alternating the number of season workers and by driving machines in two shifts. It is possible, if some environmental problems of large-scale summer time harvesting can be solved.

  • Rummukainen, ORCID ID:E-mail:
  • Alanne, ORCID ID:E-mail:
  • Mikkonen, ORCID ID:E-mail:
article id 7630, category Article
Esko Mikkonen. (1983). Eräiden matemaattisen ohjelmoinnin menetelmien käyttö puun korjuun ja kuljetuksen sekä tehdaskäsittelyn menetelmävalinnan apuvälineenä. Acta Forestalia Fennica no. 183 article id 7630. https://doi.org/10.14214/aff.7630
English title: The usefulness of some techniques of the mathematical programming as a tool for the choice of timber harvesting system.

The applicability of five mathematical programming methods, namely standard linear programming, parametric programming, goal programming, mixed integer programming and integer programming is discussed as a planning tool for the choice of wood procurement method.

Theoretically, the goal programming approach seems to be the best routine for mathematical handling of problems related to wood procurement. The parametric approach must include enough large post-optimality analysis routine. If the effect of the variables expressed with different measures is to be studied, interpretation of the economic information given by the approach becomes a problem. The other drawback is that the approach does not allow determination of the hierarchy of the goals objectively as they depend on the subjective preferences of the decision maker.

From the practical point of view, standard linear programming is the best method if the objective function can be formulated in economic terms, for instance. If there are several goals to be attained or satisfied the best method is goal programming.

According to the sub-studies, every method under consideration can be used as a solution routine for the minimization of wood procurement costs. In cost minimization the best methods are goal programming and standard linear programming. The best method for harvesting system evaluation purposes is parametric because it allows varied cost calculations within a certain cost range. The best method for harvesting equipment investment planning is mixed integer programming with binary decision variables.

The more complicated and restricted the problem environment is, the better the mathematical programming approach will be, also in harvesting related problems.

The PDF includes a summary in English.

  • Mikkonen, ORCID ID:E-mail:

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