scholarly journals Simulation-Based Cost Analysis of Industrial Supply of Chips from Logging Residues and Small-Diameter Trees

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Raul Fernandez-Lacruz ◽  
Anders Eriksson ◽  
Dan Bergström

Research Highlights: The use of terminals can increase supply costs by 5–11% (when compared to direct supply), but terminals help secure supply during peak demand and cope with operational problems in the supply fleet in cases where direct supply chains would be unable to meet demand on time. Background and Objectives: This work analyses the supply cost of chipped logging residues and small-diameter trees, from chipping at roadside storages to delivery to the end-user. Factors considered include demand curves (based on the requirements of a theoretical combined heat and power plant or biorefinery); demand volume; and mode of supply (direct or combined via terminal). The impact of longer trucking distances from the sites, and supply integration between forest and other land (varying relocation distances) was also assessed. Materials and Methods: The operational environment and work of a theoretical chip supplier in northern Sweden were modelled and simulated in ExtendSim®. Results: The mean supply cost of chips was 9% higher on average for combined chains than for direct chains. Given a high demand, 8% of the annual demand could not be delivered on time without using a terminal. High supply integration of forest and other land reduced supply costs by 2%. Contractors’ annual workloads were evened out by direct supply to the biorefinery (which has a relatively steady demand) or supply via-terminal independently of the end-user. Keeping distinct chips from different sites (implying that trucks were not always fully loaded) instead of mixing chips from different sites until the trucks were fully loaded increased supply costs by 12%. Conclusions: Terminals increase supply costs, but can enable demand to be met on time when direct supply chains alone might fail. Integrated supply planning could reduce supply costs by increasing the utilization of residual biomass from other land.

1993 ◽  
Vol 23 (5) ◽  
pp. 799-809 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Harry Coates ◽  
Les A. Jozsa ◽  
Paul K. Diggle

This study assessed the impact of feeding injuries by snowshoe hare (Lepusamericanus Erxleben) and red squirrel (Tamiasciurushudsonicus Erxleben) on diameter growth, height growth, and wood quality of juvenile lodgepole pine (Pinuscontorta Dougl. var latifolia Engelm.) at Prince George and in the Cariboo Region, British Columbia. In the Prince George control stand, severe girdling damage (50–99% stem circumference) suppressed diameter and height growth of small-diameter (4.1–6.0 cm) trees, but had no effect on larger stems (6.1–8.0 cm). In the spaced stand, diameter and height increments also declined significantly with degree of partial girdling, particularly in small-diameter (3.1–5.0 cm) trees. Paradoxically, diameter increment increased significantly with degree of partial girdling in both stands at the Cariboo study area. Presumably squirrels prefer to feed on vigorous stems, and the lost growth of these trees may be substantial. There was no significant difference in amount of compression wood nor total solvent and water extractives between undamaged and damaged trees. Fiber lengths in wound-associated wood were consistently 19–21% lower than in controls. Damaged trees had greater average ring width and density than undamaged trees. The average increase in relative density of damaged over undamaged trees was 0.0343. These results suggest that a severe degree of partial girdling (which likely occurs more often in small-diameter trees) may significantly affect growth of lodgepole pine, particularly small (<5.0 cm DBH) trees.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Gunnar Eriksson ◽  
Dimitris Athanassiadis ◽  
Dan Bergström ◽  
Tomas Nordfjell ◽  
Urban Bergsten

Increasing use of woody fuels requires that nontraditional types of raw materials are exploited, including logging residues and small-diameter trees. Although medium-scale combustors often use pellets, they could conceivably use dried chips of sufficiently narrow size distribution (henceforth pellet chips). The influence of the following factors on the relative cost-effectiveness of producing pellets and pellet chips was investigated for three plant sites in northern Sweden: (1) harvesting and transporting of forest residues; (2) the potential of existing energy plants to supply drying heat in periods of capacity surplus; (3) the distance to potential end-users. Data from the national forest inventory were used to estimate raw material costs. The resulting production costs were 144–176 $ per oven-dry tonnes (OD t) for pellets (27.4–33.5 $ MWh−1) and 143–173 $ OD t−1(27.2–33.0 $ MWh−1) for pellet chips, with harvesting, forwarding, chipping, and transporting of logging residues to the sites amounting to 114–122 $ OD t−1(21.7–23.2 $ MWh−1) for both fuels. Even though the differences in production costs were minor, the production of pellet chips requires significantly less electricity input per OD t of produced fuel. For cost reductions improved methods for wood fuel procurement, compacting and transporting of chips, small-scale low-temperature drying and foliage and bark separation are needed.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 579 ◽  
Author(s):  
Jannike Sophie Unger ◽  
Christoph Glasner

This work assesses the costs of exploiting the biomass feedstock chaff. Chaff is a harvest residue generated during the conventional grain harvesting process and usually remains on the field. In this paper, the costs of collecting and supplying chaff to the end user with different harvesting methods and supply chains are analyzed. The costs are estimated for a base case defining a set of general assumptions. The impact of these assumptions is analyzed in a sensitivity analysis by means of tornado diagrams. A full costing method based on the VDI guideline 2067 part 1 is applied for the cost estimation. The cost analysis reveals that ceasing the fractioning of grain, straw and chaff during harvesting and transporting them as a mixture reduces the harvesting costs significantly. The costs are decreased due to a reduction in agricultural operations and processing large amounts of material. The lowest total costs originate from the production of chaff-straw bales. Harvesting chaff as a single fraction leads to the highest costs with the investigated supply chains. Comparing the costs of chaff supply to potential revenues shows that an exploitation of the harvest residue can be economically feasible.


2021 ◽  
Author(s):  
Rumeng He ◽  
Xuhu Wang ◽  
Tao Liu ◽  
Lijun Guo ◽  
Baitian Wang ◽  
...  

Abstract With climate change, understanding tree responses to climate is important for predicting trees’ growth, and plant competition as a nonnegligible biotic factor plays a key role in such response. However, few studies have investigated how competition affects the response of Pinus tabulaeformis plantations to climate . In our study, we investigated nine 29-year-old P. tabulaeformis plantation plots (three density gradients). The dendroecological method was used to analyze the impact of competition on trees response to drought and interannual climate variation. Stand density index was used to indicate the intensity of competition. The results showed that competition modified the climate-growth relationship. Competition increased trees’ sensitivity to drought but the relationship between competition and sensitivity to drought was nonlinear. The competition effect slightly increased under intense competition conditions. Additionally, competition reduced trees’ sensitivity to interannual climate variation. After 1999, the effect of competition was obvious. The sensitivity of small-diameter trees, especially those in middle- and high-density stands, declined. Thus, in the future these trees presumably may exhibit a reduced sensitivity to interannual climate variation and a greater sensitivity to drought.


2020 ◽  
Vol 38 (7A) ◽  
pp. 1069-1076
Author(s):  
Layth T. Ali ◽  
Raid S. Abid Ali ◽  
Zeyad S. M. Khaled

Cost overrun in construction projects is a common phenomenon in Iraq. This might occur due to diversity of factors. This study aims to identify the factors influencing construction projects cost that are potentially controllable by main contractors. A field study through a questionnaire survey was directed to a sample of related Iraqi professional engineers from general contracting companies at both public and private sectors. Their opinions on the impact and frequency of each factor were investigated. The questionnaire offered (59) factors classified in (8) categories namely; legislations, financial and economic, design, contractual, site management, material, labor and equipment. The factors were ranked according to the highest Relative Importance Index (RII). The study revealed (10) major factors that are potentially controllable by main contractors namely; labor productivity, sub-contractors and suppliers performance, equipment productivity, site organization and distribution of equipment, experience and training of project managers, scheduling and control techniques, planning for materials supply, planning for equipment supply, materials delivery and planning for skilled labor recruitment. Recommendations to aid contractors and owners in early identification of these factors are also included in this study.


Logistics ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 12
Author(s):  
Lakshmy Subramanian

Health supply chains aim to improve access to healthcare, and this can be attained only when health commodities appropriate to the health needs of the global population are developed, manufactured, and made available when and where needed. The weak links in the health supply chains are hindering the access of essential healthcare resulting in inefficient use of scarce resources and loss of lives. A chain is only as strong as its weakest link, and demand forecasting is one of the weakest links of health supply chains. Also, many of the existing bottlenecks in supply chains and health systems impede the accurate forecasting of demand, and without the ability to forecast demand with certainty, the stakeholders cannot plan and make commitments for the future. Forecasts are an important feeder for budgeting and logistics planning. Under this backdrop, the study examines how improved forecasting can lead to better short-term and long-term access to health commodities and outlines market-related risks. It explores further how incentives are misaligned creating an uneven distribution of risks, leading to the inability to match demand and supply. For this purpose, a systematic literature review was performed, analyzing 71 articles from a descriptive and content approach. Findings indicate the emerging trends in global health and the consequences of inaccurate demand forecasting for health supply chains. The content analysis identifies key factors that can pose a varying degree of risks for the health supply chain stakeholders. The study highlights how the key factors emerge as enablers and blockers, depending on the impact on the overall health supply chains. The study also provides recommendations for actions for reducing these risks. Consequently, limitations of this work are presented, and opportunities are identified for future lines of research. Finally, the conclusion confirms that by adopting a combination of approaches, stakeholders can ensure better information sharing, identify avenues of diversifying risks, and understand the implications.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
S Houwaart

Abstract End-user (e.g. patients or the public) testing of information material is becoming more common in the German public health care system. However, including the end-user (in this case patients) in an optimisation process and thus enabling a close collaboration while developing PIMs is still rare. This is surprising, given the fact that patients provide the exact perspective one is trying to address. Within the isPO project, a patient organization is included as a legal project partner to act as the patient representative and provide the patient's perspective. As such, the patient organization was included in the PHR approach as part of the PIM-optimisation team. During the optimisation process, the patients gave practical insights into the procedures of diagnosing and treating different types of cancer as well as into the patient's changing priorities and challenges at different time points. This was crucial information for the envisioned application of the individual PIMs and their hierarchical overview. Moreover, the developed PIM-checklist enabled the patients to give detailed feedback to the PIMs. With their experience of being in the exact situation in which the PIMs will be applied, their recommendations, especially on the wording and layout of the materials, have been a valuable contribution to the PIM optimisation process. In this part of the seminar, we will take a closer look at the following skill building aspects: What is gained from including patients as end-users in the development and optimization of PIM?How can we reach patients to contribute to a PIM optimization process? Which requirements and prerequisites do patients have to provide to successfully work on an optimisation team?How to compromise and weigh opinions when different ideas occur? Altogether, this part will construct a structured path of productive patient involvement and help to overcome uncertainties regarding a collaboration with patient organizations.


2021 ◽  
Vol 13 (11) ◽  
pp. 6372
Author(s):  
Vincenzo Varriale ◽  
Antonello Cammarano ◽  
Francesca Michelino ◽  
Mauro Caputo

The digital transformation of supply chains should revolutionize entire management processes and improve various aspects of sustainability. In particular, the plans of Industry 4.0 aim towards a digitization of several procedures by exploiting emerging technologies such as the Internet of Things, RFID and blockchain. The purpose of this study is to highlight how order and disruption events processes can be improved with the adoption of emerging technologies and how this reflects on the improvement of sustainability aspects. The study is based on the comparison of two simulation scenarios between three actors in the cheese supply chain. In particular, a first traditional scenario “as is” is simulated without the use of new technologies and is compared to a second scenario “to be” that adopts IoT, RFID and blockchain. The results show an improvement in time performance for managing both perfect and non-compliant orders. The developed framework highlights the impact of new technologies on sustainability aspects, showing further managerial implications.


2021 ◽  
Vol 13 (3) ◽  
pp. 1464
Author(s):  
Patrick Brandtner ◽  
Farzaneh Darbanian ◽  
Taha Falatouri ◽  
Chibuzor Udokwu

The COVID-19 pandemic has been one of the biggest disruptive events of recent decades and has had a global effect on society and the economy. The political regulations resulting from COVID-19 also led to significant changes in physical grocery shopping. However, the specific impact of COVID-19 on consumer satisfaction at the customer end of retail supply chains, i.e., the point-of-sale (PoS), has not yet been addressed. By gathering and analyzing consumer satisfaction data (ratings) and sentiments (evaluation comments) available on the open web, the current study evaluates the impact of COVID-19 on consumer satisfaction at the PoS. Focusing on the five biggest retail chains in Austria, the results show that there was a general and significant decline in consumer satisfaction due to the pandemic. The results also show a high impact of political regulations on consumer satisfaction. Furthermore, the text-mining based analysis of evaluation comments indicate that store layout and facilities, as well as product availability and waiting time had a great impact on consumer satisfaction. In total, over 533,000 consumer satisfaction ratings and over 153,000 textual comments have been analyzed, providing the basis for a comprehensive and sound discussion of the impact of COVID-19 on consumer satisfaction and perceptions. Future research could focus on applying the used data analysis technique and the adapted consumer sentiment dimensions in different settings, such as countries other than Austria or smaller retail chains.


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