scholarly journals Incorporating Regeneration Effort as a Decision Variable in Tactical Harvest Scheduling

2009 ◽  
Vol 24 (2) ◽  
pp. 61-66 ◽  
Author(s):  
Kevin Boston ◽  
John Sessions ◽  
Robin Rose ◽  
Will Hoskins

Abstract A variable green-up period is incorporated into a tactical harvest scheduling model to allow for the regeneration policy to be included as a decision variable. The benefit of this formulation was demonstrated by solving a 91-logging unit forest plan under four different green-up policies.The first three policies used fixed green-up periods of 2, 3, and 4 years. The fourth policy uses a variable green-up period where the model selects the regeneration effort that determines the green-up period stand by stand. This policy allows each harvested stand to choose among a 2-, 3-,or 4-year green-up period. The variable green-up period resulted in a slight improvement in the net present value because its total was approximately $3,000 or $1.11/ac higher for the total planning area, not just the harvested acres when compared with the best solutions when 4-, 3-, and 2-year fixed green-up periods were used. The variable green-up constraint adds a level of complexity to the spatial harvest scheduling problem that is easily incorporated into a variety of heuristic procedures because they do not require that all combinations of harvest units be specified before solving the problem. The results cannot be generalized to other forests because the spatial arrangement of the stands is a major component in the value determination. However, using the methodology presented, forest managers can evaluate their own alternatives that may improve the returns from managing their resources.

2005 ◽  
Vol 29 (4) ◽  
pp. 185-193 ◽  
Author(s):  
Wise H. Batten ◽  
Pete Bettinger ◽  
Jianping Zhu

Abstract Forest plans related to a number of spatial harvest scheduling scenarios were developed for a medium-sized forest holding using a heuristic forest planning technique (tabu search). Green-up periods of 2 to 7 years were assessed in conjunction with the two types of adjacency constraints. The results indicate for this one property that a short green-up period (2–3 years) did not significantly affect the economic value of the forest holding studied. Longer green-up periods and smaller maximum clearcut sizes could reduce the net present value of this forest holding by as much as 5 to 15% depending on the clearcut adjacency rules used. In a validation of the heuristic solutions, we found that the best solution generated with the heuristic (for three separate problems) was within 0.25% of the integer programming solution. South. J. Appl. For. 29(4):185–193.


1988 ◽  
Vol 5 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Douglas C. Macmillan ◽  
Stephen E. Fairweather

Abstract The technique of linear programming (LP) is illustrated by developing a harvest schedule for an industrial forest ownership in northwestern Pennsylvania. The objective was to maximize net present value of the harvest over a five-year planning period. The effect of changes in timber value and growth rate on the optimum schedule was determined. Sensitivity analysis provided additional information the manager could use to make decisions. In order to successfully apply LP, the forester must be able to define the management objective of the harvest schedule and the resource and managerial constraints that will influence its attainment. Data used in the model have to be available and reliable. Many forest enterprises should be in the position to adopt LP since commercial programs for microcomputers are now available for which a high level of computing expertise is not required. North. J. Appl. For. 5:145-148, June 1988.


2010 ◽  
Vol 40 (6) ◽  
pp. 1136-1154 ◽  
Author(s):  
David W. Savage ◽  
David L. Martell ◽  
B. Mike Wotton

We embedded a linear programming timber harvest scheduling model into an aspatial stochastic simulation model of a flammable forest to evaluate two fire risk mitigation strategies. The harvest scheduling model is solved repeatedly to produce harvest schedules within a rolling planning horizon framework. The risk mitigation strategies we examined were (1) whether or not to account for fire in the planning model and (2) replanning interval. We evaluated those strategies under four representative fire regimes. We found that accounting for fire in the planning model reduced the harvest volume variability as fire activity increased (i.e., for average annual burn fractions ≥0.45%), but replanning intervals over a range of 1 to 10 years had little impact on harvest volume variability. We also developed a risk analysis decision-making aid that forest managers can use to help deal with fire-related uncertainty. Our results suggest that risk-averse forest managers should account for fire while planning, especially when burn fractions exceed 0.45%.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 651
Author(s):  
Andrés Hirigoyen ◽  
Mauricio Acuna ◽  
Cecilia Rachid-Casnati ◽  
Jorge Franco ◽  
Rafael Navarro-Cerrillo

Quantifying the impact of carbon (C) and timber prices on harvest scheduling and economic returns is essential to define strategies for the sustainable management of short-rotation plantations so that they can provide timber products and contribute to C sequestration. In this paper, we present a mixed-integer linear programming model that optimizes harvest scheduling at the forest level, C sequestration, and Net Present Value (NPV) over a planning period of up to 15 years. The model included revenue from the sale of timber (pulplogs) and credits from the net C sequestered during the life of the stands. In addition, plantation establishment, management, harvesting, and transportation costs were included in the analysis. The study area comprised 88 Eucalyptus grandis W. Hill and Eucalyptus dunnii Maiden stands located in Uruguay, totaling a forest area of nearly 1,882 ha. The study investigated the impact of C and timber prices on NPV, harvest schedules, stands’ harvest age, timber flows to customers, and C sequestered per period. The maximum NPV among all the scenarios evaluated (USD 7.53 M) was calculated for a C price of 30 USD t−1, an interest rate of 6%, and a timber price of 75 USD m−3. This was USD 2.14 M higher than the scenario with the same parameters but that included only revenue from timber. C prices also impacted stands’ harvest age, C sequestration, and timber flows delivered to end customers. On average, in scenarios that included C prices, timber flows and C sequestration increased by 15.4 and 12.1%, respectively, when C price increased from 5 to 30 USD t−1. These results demonstrate that harvest scheduling, harvest age, and NPV are very sensitive to C and timber, and that the best economic returns are obtained when the stands are managed to maximize timber production and C sequestration.


2017 ◽  
Vol 2 (1) ◽  
pp. 21-30
Author(s):  
Muhammad Jamil ◽  
Januari Frizki Bella

Adapun tujuan dari Penelitian ini adalah untuk mengetahui kelayakan usaha industri pengolahan kecap Aneka Guna apabila dilihat dari segi kelayakan finansial. Penelitian ini menggunakan metode studi kasus. Lokasi penelitian yaitu di Kota Langsa dengan pertimbangan bahwa lokasi tersebut merupakan daerah yang terdapat industri pengolahan kecap asin dan mudah di jangkau oleh penulis. Waktu penelitian dilaksanakan pada Bulan Juni - Oktober 2014. Tenaga kerja yang digunakan berjumlah 27 orang, 20 tenaga kerja pria dan 7 orang tenaga kerja wanita. Jumlah penggunaan tenaga kerja selama 5 tahun sebesar 3759 HKP. Total biaya produksi yang dikeluarkan oleh pengusaha dalam usaha pembuatan kecap didaerah penelitian selama 5 tahun adalah Rp. 2.076.988.000,-. Pendapatan kotor yang diperoleh pengusaha sebesar Rp. 8.199.690.000,- dan pendapan bersih yang diperoleh sebesar Rp. 6.122.702.000,-                 Kota Langsa hanya memiliki 1 pengusaha pengolahan kecap asin dan dijadikan sebagai pengusaha sampel yaitu usaha industri pengolahan kecap asin Aneka Guna. Hasil perhitungan di peroleh Net Present Value (NPV) sebesar Rp. 263.281.290 (lebih besar dari nol), sedangkan Internal Rate of Return (IRR) sebesar 84% lebih besar dari tingkat bunga yang berlaku (D.F. = 18%), sedangkan Net B/C Ratio sebesar 3,27 (lebih dari pada 1) dan Pay Back Priod (PBP) 1 Tahun 6 Bulan (lebih kecil dari umur ekonomis).  


Author(s):  
Ainārs GRĪNVALDS

The stand selection for cutting in tactical planning should be done according to the same principles like in strategic planning – to maximize net present value. The simple way of how to transfer the net present value maximization principle from strategic planning to tactical planning was created in Sweden. The method is based on annual changes in the net present value by postponing final felling. Forest inventory data and forestry modelling system was used for calculation of changes in net present value for pine, spruce, birch, aspen and black alder stands. And changes in net present value were described by regression function with factors from stand parameters. The regression function allows calculating annual changes in net present value for each stand. And stands with higher decrease in net present value have higher cutting priority. Stands selected for the final felling in strategic plan were compared with the stands selected in tactical plan with two methods, first, by using annual changes in the net present value, second, by traditional planning principles. Stands selected by annual changes in the net present value were similar to stands that were selected for cutting in strategic plan, but stands selected by traditional planning principles – not.


2017 ◽  
Vol 13 (3) ◽  
pp. 240
Author(s):  
Novdin M Sianturi

Abstrak: Pengelolaan sampah di Kota Pematangsiantar masih bertumpu pada pendekatan akhir (kumpul-angkut-buang), dengan tingkat pelayanan yang rendah, sehingga untuk meningkatkan pelayanan sampah, perlu dilakukan pemilahan di tempat penampungan sementara (TPS). Penelitian ini bertujuan untuk mengkaji sistem pengelolaan sampah dengan melakukan pemilihan di TPS dapat meningkatkan pelayanan aset persampahan sampai tahun  2015 secara teknis operasional dan dari aspek keuangan. Analisa teknis operasional aset pengelolaan sampah mulai dari pewadahan, pengumpulan dan pengangkutan sedangkan analisa keuangan dan analisa kelayakan menggunakan Net Present Value, Internal Rate of Return, Benefit/Cost Ratio, dan Payback Period. Dari hasil analisa tersebut diperoleh suatu sistem pengelolaan sampah dengan pemilihan di TPS berdasarkan zona pelayanan dengan skala prioritas secara bertahap daritahun 2013-2017, dapat meningkatkan cakupan pelayanan sampah eksisting rata-rata 6,69 %, cakupan pelayanan TPS eksisting rata-rata 8,29 %, dan cakupan pelayanan truk pengangkut sampah eksisting rata-rata 12,03 %. Investasinya layak, diperoleh Net Cashflow pada tahun 2020 sebesar Rp 1.720.242.284,-, NPV suku bunga 15 % bernilai positif, IRR > MARR 15 %,  B/C Ratio > 1, dan PP 4,7 tahun, lebih pendek dari periode investasi 10 tahun. Dari Metode penelitian ini maka pengumpulan data, observasi lapangan dan pengukuran contoh timbulan sampah dengan sampel 4 TPS perumahan yang terlayani pengangkutan.


Author(s):  
Wahyu Setiawan ◽  
Atikah Nurhayati ◽  
Titin Herawati ◽  
Asep Agus Handaka

Gill net is one of the fishing gear used by Jatigede Reservoir fisherman. The purpose of this research is to analyzed the feasibility of fish catching business with gill net in Jatigede Reservoir. This research was conducted by used data collection method (observation, questioner, literature study) and method of data analysis (feasibility business analysis). The benefits of this research is expected to be informations and references for the research who will expand a fishing business with gill net at Jatigede Reservoir. The result of feasibility of fish catching business with gill net at Jatigede Reservoir is profit value Rp. 70.890.000, Break Event Point price and production (all species of fish) Rp. 4.154/kg and 2.136kg in a year, Benefit Cost Ratio 3,37, Payback Period 2 months and Net Present Value >1 Rp. 52.820.243, the fish catching business using gill net at Jatigede Reservoir is feasible to be developed.


2017 ◽  
Vol 16 (2) ◽  
pp. 38
Author(s):  
Rama Dwi Aryandi ◽  
Ari Sandhyavitri ◽  
Reni Suryanita

Penelitian ini bertujuan untuk menganalisis tingkat pelayanan simpang berdasarkan data lalu lintas simpang tersebut apakah derajat jenuhnya sudah melewati ambang batas DS = 0,75, jika nilai DS>0,75, akan dikaji penerapan beberapa alternatif penanganan untuk meningkatkan tingkat pelayanan simpang, untuk kemudian dipilih lagi alternatif terbaik untuk jangka pendek, menengah dan panjang. Metode pengumpulan data yang digunakan dalam penelitian ini adalah metode traffic counting, sedangkan untuk pengkajian alternatif penanganan simpang secara teknik menggunakan metode MKJI 1997, secara ekonomi menggunakan metode LAPI ITB, analisa nilai waktu dengan nilai waktu hasil penelitian Dirjen Bina Marga dan analisa biaya investasi dengan analisa Benefit Cost Ratio dan Net Present Value.  Dari tiga alternatif manajemen lalu lintas yang diajukan, hanya alternatif ke-3 yaitu kombinasi peniadaan hambatan samping, pelarangan belok kiri dan optimasi traffic light  yang menghasilkan nilai DS<0,75 untuk kondisi eksisting, sedangkan untuk tahun 2020 nilai DS-nya adalah 0,79 untuk Hari Selasa dan 0,83 untuk Hari Rabu. Sedangkan dengan alternatif pembangunan flyover, untuk jangka pendek atau 5 tahun nilai BCR dan NPV-nya 1,25 dan 48,9 milyar rupiah, tahun ke-10  2,29 dan 256,4 milyar rupiah, serta tahun ke-15 3,35 dan 472,19 milyar rupiah, sehingga dapat disimpulkan bahwa pembangunan flyover adalah solusi penanganan terbaik untuk menignkatkan kinerja Simpang Pasar Pagi Arengka.


2018 ◽  
Vol 3 (2) ◽  
pp. 160
Author(s):  
Halkadri Fitra ◽  
Salma Taqwa ◽  
Charoline Cheisviyanny ◽  
Abel Tasman ◽  
Nurzi Sebrina

Penelitian ini bertujuan untuk melihat kelayakan aspek keuangan usaha grosir sembako Badan Usaha Milik Desa (Nagari) Kamang Hilia Sejahtera di Kenagarian Kamang Hilia Kecamatan Kamang Magek Kabupaten Agam Provinsi Sumatera Barat yang dilakukan pada tahun 2018. Penelitian bersifat deskriptif kuantitatif dengan menggunakan metode cash flow analysis, payback period, net present value, profitability index, internal rate of return, dan average rate of return. Hasil penelitian menunjukkan bahwa nilai net cash flow Badan Usaha Milik Desa (Nagari) Kamang Hilia Sejahtera adalah positif yaitu Rp.21.774.000, nilai payback period adalah 1,15 tahun, nilai net present value positif sebesar Rp.10.680.034,47, nilai profitability index adalah positif 1,37, sedangkan nilai internal rate of return adalah 46,7% dan nilai average rate of return adalah 57,23%. Berdasarkan standar penilaian maka semua metode yang digunakan memberikan kesimpulan bahwa usaha grosir sembako milik Badan Usaha Milik Desa (Nagari) Kamang Hilia Sejahtera dalam kategori layak untuk dilaksanakan.


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